Credit: Fizkes/Shutterstock

Over the course of this pandemic, significant progress has been made in treating COVID-19 and helping to save lives. That progress includes the development of life-preserving monoclonal antibody infusions and repurposing existing drugs, to which NIH’s Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) public-private partnership has made a major contribution.

But for many months we’ve had hopes that a safe and effective oral medicine could be developed that would reduce the risk of severe illness for individuals just diagnosed with COVID-19. The first indication that those hopes might be realized came from the announcement just a month ago of a 50 percent reduction in hospitalizations from the Merck and Ridgeback drug molnupiravir (originally developed with an NIH grant to Emory University, Atlanta). Now comes word of a second drug with potentially even higher efficacy: an antiviral pill from Pfizer Inc. that targets a different step in the life cycle of SARS-CoV-2, the novel coronavirus that causes COVID-19.

The most recent exciting news started to roll out earlier this month when a Pfizer research team published in the journal Science some promising initial data involving the antiviral pill and its active compound [1]. Then came even bigger news a few days later when Pfizer announced interim results from a large phase 2/3 clinical trial. It found that, when taken within three days of developing symptoms of COVID-19, the pill reduced by 89 percent the risk of hospitalization or death in adults at high risk of progressing to severe illness [2].

At the recommendation of the clinical trial’s independent data monitoring committee and in consultation with the U.S. Food and Drug Administration (FDA), Pfizer has now halted the study based on the strength of the interim findings. Pfizer plans to submit the data to the FDA for Emergency Use Authorization (EUA) very soon.

Pfizer’s antiviral pill is a protease inhibitor, originally called PF-07321332, or just 332 for short. A protease is an enzyme that cleaves a protein at a specific series of amino acids. The SARS-CoV-2 virus encodes its own protease to help process a large virally-encoded polyprotein into smaller segments that it needs for its life cycle; a protease inhibitor drug can stop that from happening. If the term protease inhibitor rings a bell, that’s because drugs that work in this way already are in use to treat other viruses, including human immunodeficiency virus (HIV) and hepatitis C virus.

In the case of 332, it targets a protease called Mpro, also called the 3CL protease, coded for by SARS-CoV-2. The virus uses this enzyme to snip some longer viral proteins into shorter segments for use in replication. With Mpro out of action, the coronavirus can’t make more of itself to infect other cells.

What’s nice about this therapeutic approach is that mutations to SARS-CoV-2’s surface structures, such as the spike protein, should not affect a protease inhibitor’s effectiveness. The drug targets a highly conserved, but essential, viral enzyme. In fact, Pfizer originally synthesized and pre-clinically evaluated protease inhibitors years ago as a potential treatment for severe acute respiratory syndrome (SARS), which is caused by a coronavirus closely related to SARS-CoV-2. This drug might even have efficacy against other coronaviruses that cause the common cold.

In the study published earlier this month in Science [1], the Pfizer team led by Dafydd Owen, Pfizer Worldwide Research, Cambridge, MA, reported that the latest version of their Mpro inhibitor showed potent antiviral activity in laboratory tests against not just SARS-CoV-2, but all of the coronaviruses they tested that are known to infect people. Further study in human cells and mouse models of SARS-CoV-2 infection suggested that the treatment might work to limit infection and reduce damage to lung tissue.

In the paper in Science, Owen and colleagues also reported the results of a phase 1 clinical trial with six healthy people. They found that their protease inhibitor, when taken orally, was safe and could reach concentrations in the bloodstream that should be sufficient to help combat the virus.

But would it work to treat COVID-19 in an infected person? So far, the preliminary results from the larger clinical trial of the drug candidate, now known as PAXLOVID, certainly look encouraging. PAXLOVID is a formulation that combines the new protease inhibitor with a low dose of an existing drug called ritonavir, which slows the metabolism of some protease inhibitors and thereby keeps them active in the body for longer periods of time.

The phase 2/3 clinical trial included about 1,200 adults from the United States and around the world who had enrolled in the clinical trial. To be eligible, study participants had to have a confirmed diagnosis of COVID-19 within a five-day period along with mild-to-moderate symptoms of illness. They also required at least one characteristic or condition associated with an increased risk for developing severe illness from COVID-19. Each individual in the study was randomly selected to receive either the experimental antiviral or a placebo every 12 hours for five days.

In people treated within three days of developing COVID-19 symptoms, the Pfizer announcement reports that 0.8 percent (3 of 389) of those who received PAXLOVID were hospitalized within 28 days compared to 7 percent (27 of 385) of those who got the placebo. Similarly encouraging results were observed in those who got the treatment within five days of developing symptoms. One percent (6 of 607) on the antiviral were hospitalized versus 6.7 percent (41 of 612) in the placebo group. Overall, there were no deaths among people taking PAXLOVID; 10 people in the placebo group (1.6 percent) subsequently died.

If all goes well with the FDA review, the hope is that PAXLOVID could be prescribed as an at-home treatment to prevent severe illness, hospitalization, and deaths. Pfizer also has launched two additional trials of the same drug candidate: one in people with COVID-19 who are at standard risk for developing severe illness and another evaluating its ability to prevent infection in adults exposed to the coronavirus by a household member.

Meanwhile, Britain recently approved the other recently developed antiviral molnupiravir, which slows viral replication in a different way by blocking its ability to copy its RNA genome accurately. The FDA will meet on November 30 to discuss Merck and Ridgeback’s request for an EUA for molnupiravir to treat mild-to-moderate COVID-19 in infected adults at high risk for severe illness [3]. With Thanksgiving and the winter holidays fast approaching, these two promising antiviral drugs are certainly more reasons to be grateful this year.

References:

[1] An oral SARS-CoV-2 M(pro) inhibitor clinical candidate for the treatment of COVID-19.Owen DR, Allerton CMN, Anderson AS, Wei L, Yang Q, Zhu Y, et al. Science. 2021 Nov 2: eabl4784.

[2] Pfizer’s novel COVID-19 oral antiviral treatment candidate reduced risk of hospitalization or death by 89% in interim analysis of phase 2/3 EPIC-HR Study. Pfizer. November 5, 2021.

[3] FDA to hold advisory committee meeting to Discuss Merck and Ridgeback’s EUA Application for COVID-19 oral treatment. Food and Drug Administration. October 14, 2021.

Links:

COVID-19 Research (NIH)

Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) (NIH)

A Study of PF-07321332/Ritonavir in Nonhospitalized Low-Risk Adult Participants With COVID-19 (ClinicalTrials.gov)

A Post-Exposure Prophylaxis Study of PF-07321332/Ritonavir in Adult Household Contacts of an Individual With Symptomatic COVID-19 (ClinicalTrials.gov)

I got my booster shot last week. The process was extremely quick and easy, and I felt great afterwards. I received my first dose of the Moderna vaccine in December 2020 and the second dose in January 2021. So, it was definitely time for me to get my Moderna booster. If you haven’t already, please consider getting a COVID-19 booster shot to protect your health entering the winter holiday season. Credit: NIH

Credit: bbernard/Shutterstock

The winter holidays are approaching, and among the many things to be grateful for this year is that nearly 200 million Americans are fully vaccinated for COVID-19. That will make it safer to spend time with friends and family, though everyone should remain vigilant just to be on the safe side. Though relatively uncommon, breakthrough infections are possible. That’s why the Centers for Disease Control and Prevention (CDC) recommends booster shots for several at-risk groups, including folks 65 years and older, those with underlying medical conditions, and people whose occupations place them at high risk of exposure.

One of the main studies providing the evidence for CDC’s recommendation was recently published in the New England Journal of Medicine [1]. It found that vaccine-induced immunity, while still quite protective against infection and severe illness from COVID-19, can wane after several months.

The study is yet another highly informative report from Israel, where public health officials launched a particularly vigorous national vaccination campaign in December 2020. More than half of adult Israelis received two doses of the Pfizer vaccine within the first three months of the campaign. By May 2021, Israel had extremely small numbers of confirmed COVID-19 cases—just a few dozen per day.

But the numbers crept back up in June 2021. The rise also included a substantial number of breakthrough infections in vaccinated individuals. The vast majority of those cases in June—98 percent—were caused by the emerging Delta variant.

Researchers led by Yair Goldberg, Technion-Israel Institute of Technology, Haifa, wondered whether this resurgence of COVID-19 could be fully explained by the rise of the more infectious Delta variant. Or, they wondered, did the waning of immunity over time also play a role?

To find out, the researchers looked to over 4.7 million fully vaccinated Israeli adults, more than 13,000 of whom had breakthrough infections from July 11 to 31, 2021 with SARS-CoV-2. The researchers looked for an association between the rate of confirmed infections and the time that had passed since vaccination. Without any significant waning of immunity, one shouldn’t see any difference in infection rates among people who were fully vaccinated at the earliest opportunity versus those vaccinated later.

The results were clear: the rate of confirmed COVID-19 infection revealed a slow but steady waning of immunity over time. Among individuals 60 years or older who were fully vaccinated last January, the number of confirmed breakthrough infections was 3.3 per 1,000 people during the three weeks of the study. Those who were vaccinated in February and March had lower infection rates of 2.2 per 1,000 and 1.7 per 1,000, respectively. The data revealed a similar pattern in those aged 40 to 59 and those aged 16 to 39.

An important question is whether these breakthrough infections were serious enough to require hospitalization. While such cases were much less common, more than 400 of those with confirmed COVID-19 breakthroughs went on to develop severe illness. And, again, the data show a similar pattern of waning immunity. The rate of severe COVID-19 among adults 60 years of age or older who were fully vaccinated in January was 0.34 cases per 1,000 persons. The rate of severe illness dropped to 0.26 cases per 1,000 among those vaccinated in February and 0.15 cases per 1,000 for those vaccinated in March. The researchers report that the number of severe COVID-19 cases among the younger fully vaccinated groups were too small to draw any conclusions.

While the Delta variant surely has played a role in the resurgence of COVID-19 in recent months, these findings suggest that waning immunity also is an important factor. Understanding these dynamics is essential for making critical policy decisions. In fact, these data were a key factor in the decision by the Israeli Ministry of Health in July 2021 to approve administration of COVID-19 booster shots for individuals who’d been vaccinated at least 5 months before.

Back in the U.S., if you were among those who got your vaccine on the early side—good for you. If it’s been more than six months since your original shots, and if you are in one of the risk groups, you should consider a COVID-19 booster shot to remain optimally protected in the months ahead. I’ll be getting my Moderna booster this week. While you’re at it, consider getting your annual flu shot taken care of, too. The CDC guidelines state that it’s perfectly OK to get your COVID-19 and flu shots at the same time.

Reference:

[1] Waning immunity after the BNT162b2 vaccine in Israel. Goldberg Y, Mandel M, Bar-On YM, Bodenheimer O, Freedman L, Haas EJ, Milo R, Alroy-Preis S, Ash N, Huppert A. N Engl J Med. 2021 Oct 27.Links:

COVID-19 Research (NIH)COVID-19 Vaccine Booster Shots (Centers for Disease Control and Prevention)Frequently Asked Influenza (Flu) Questions: 2021-2022 Season (CDC)

To see how COVID-19 vaccines are working in the real world, Israel has provided particularly compelling data. The fact that Israel is relatively small, keeps comprehensive medical records, and has a high vaccination rate with a single vaccine (Pfizer) has contributed to its robust data collection. Now, a new Israeli study offers some insight into those relatively uncommon breakthrough infections. It confirms that breakthrough cases, as might be expected, arise most often in individuals with lower levels of neutralizing antibodies.

The findings reported in The New England Journal of Medicine focused on nearly 1,500 of about 11,500 fully vaccinated health care workers at Sheba Medical Center, Ramat Gan, Israel [1]. All had received two doses of the Pfizer mRNA vaccine. But, from December 19, 2020 to April 28, 2021, they were tested for a breakthrough infection due to a known exposure to someone with COVID-19 or possible symptoms of the disease.

Just 39 confirmed breakthrough cases were found, indicating a breakthrough infection rate of just 0.4 percent. That’s consistent with rates reported in previous studies. Most in the Israeli study who tested positive for COVID-19 had mild or no symptoms and none required hospitalization.

In the new study, researchers led by Gili Regev-Yochay at Sheba Medical Center’s Infection Control and Prevention Unit, characterized as many breakthrough infections as possible among the health care workers. Almost half of the infections involved members of the hospital nursing staff. But breakthrough cases also were found in hospital administration, maintenance workers, doctors, and other health professionals.

The average age of someone with a breakthrough infection was 42, and it’s notable that only one person was known to have a weakened immune system. The most common symptoms were respiratory congestion, muscle aches (myalgia), and loss of smell or taste. Most didn’t develop a fever. At six weeks after diagnosis, 19 percent reported having symptoms of Long COVID syndrome, including prolonged loss of smell, persistent cough, weakness, and fatigue. About a quarter stayed home from work for longer than the required 10 days, and one had yet to return to work at six weeks.

For 22 of the 39 people with a breakthrough infection, the researchers had results of neutralizing antibody tests from the week leading up to their positive COVID-19 test result. To look for patterns in the antibody data, they matched those individuals to 104 uninfected people for whom they also had antibody test results. These data showed that those with a breakthrough infection had consistently lower levels of neutralizing antibodies circulating in their bloodstream to SARS-CoV-2, the coronavirus that causes COVID-19. In general, higher levels of neutralizing antibodies are associated with greater protection and lower infectivity—though other aspects of the immune system (memory B cells and cell-mediated immunity) also contribute.

Importantly, in all cases for which there were relevant data, the source of the breakthrough infection was thought to be an unvaccinated person. In fact, more than half of those who developed a breakthrough infection appeared to have become infected from an unvaccinated member of their own household.

Other cases were suspected to arise from exposure to an unvaccinated coworker or patient. Contact tracing found no evidence that any of the 39 health care workers with a breakthrough infection passed it on to anyone else.

The findings add to evidence that full vaccination and associated immunity offer good protection against SARS-CoV-2 infection and severe illness. Understanding how SARS-CoV-2 immunity changes over time is key for charting the course of this pandemic and making important decisions about COVID-19 vaccine boosters.

Many questions remain. For instance, it’s not clear from the study whether lower neutralizing antibodies in those with breakthrough cases reflect waning immunity or, for reasons we don’t yet understand, those individuals may have had a more limited immune response to the vaccine. Also, this study was conducted before the Delta variant became dominant in Israel (and now in the whole world).

Overall, these findings provide more reassurance that these vaccines are extremely effective. Breakthrough infections, while they can and do occur, are a relatively uncommon event. Here in the U.S., the Centers for Disease Control and Prevention (CDC) has recently estimated that infection is six times less likely for vaccinated than unvaccinated persons [2]. That those with immunity tend to have mild or no symptoms if they do develop a breakthrough case, however, is a reminder that these cases could easily be missed, and they could put vulnerable populations at greater risk. It’s yet another reason for all those who can to get themselves vaccinated as soon as possible or consider a booster shot when they become eligible.

References:

[1] Covid-19 breakthrough infections in vaccinated health care workers. Bergwerk M, Gonen T, Lustig Y, Amit S, Lipsitch M, Cohen C, Mandelboim M, Levin EG, Rubin C, Indenbaum V, Tal I, Zavitan M, Zuckerman N, Bar-Chaim A, Kreiss Y, Regev-Yochay G. N Engl J Med. 2021 Oct 14;385(16):1474-1484.

[2] Rates of COVID-19 cases and deaths by vaccination status, COVID Data Tracker, Centers for Disease and Prevention. Accessed October 25, 2021.

Links:

COVID-19 Research (NIH)

Sheba Medical Center (Ramat Gan, Israel)

Credit: Shutterstock

Any of the available COVID-19 vaccines offer remarkable personal protection against the coronavirus SARS-CoV-2. So, it also stands to reason that folks who are vaccinated will reduce the risk of spreading the virus to family members within their households. That protection is particularly important when not all family members can be immunized—as when there are children under age 12 or adults with immunosuppression in the home. But just how much can vaccines help to protect families from COVID-19 when only some, not all, in the household have immunity?

A Swedish study, published recently in the journal JAMA Internal Medicine, offers some of the first hard figures on this topic, and the findings are quite encouraging [1]. The data show that people without any immunity against COVID-19 were at considerably lower risk of infection and hospitalization when other members of their family had immunity, either from a natural infection or vaccination. In fact, the protective effect on family members went up as the number of immune family members increased.

The findings come from a team led by Peter Nordström, Umeå University, Sweden. Like in the United States, vaccinations in Sweden initially were prioritized for high-risk groups and people with certain preexisting conditions. As a result, Swedish families have functioned, often in close contact, as a mix of immune and susceptible individuals over the course of the pandemic.

To explore these family dynamics in greater detail, the researchers relied on nationwide registries to identify all Swedes who had immunity to SARS-COV-2 from either a confirmed infection or vaccination by May 26, 2021. The researchers identified more than 5 million individuals who’d been either diagnosed with COVID-19 or vaccinated and then matched them to a control group without immunity. They also limited the analysis to individuals in families with two to five members of mixed immune status.

This left them with about 1.8 million people from more than 800,000 families. The situation in Sweden is also a little unique from most Western nations. Somewhat controversially, the Swedish government didn’t order a mandatory citizen quarantine to slow the spread of the virus.

The researchers found in the data a rising protective effect for those in the household without immunity as the number of immune family members increased. Families with one immune family member had a 45 to 61 percent lower risk of a COVID-19 infection in the home than those who had none. Those with two immune family members enjoyed more protection, with a 75 to 86 percent reduction in risk of COVID-19. For those with three or four immune family members, the protection went up to more than 90 percent, topping out at 97 percent protection. The results were similar when the researchers limited the analysis to COVID-19 illnesses serious enough to warrant a hospital stay.

The findings confirm that vaccination is incredibly important not only for individual protection, but also for reducing transmission, especially within families and those with whom we’re in close physical contact. It’s also important to note that the findings apply to the original SARS-CoV-2 variant, which was dominant when the study was conducted. But we know that the vaccines offer good protection against Delta and other variants of concern.

These results show quite clearly that vaccines offer protection for individuals who lack immunity, with important implications for finally ending this pandemic. This doesn’t change the fact that all those who can and still need to get fully vaccinated should do so as soon as possible. If you are eligible for a booster shot, that’s something to consider, too. But, if for whatever reason you haven’t gotten vaccinated just yet, perhaps these new findings will encourage you to do it now for the sake of those other people you care about. This is a chance to love your family—and love your neighbor.

Reference:

[1] Association between risk of COVID-19 infection in nonimmune individuals and COVID-19 immunity in their family members. Nordström P, Ballin M, Nordström A. JAMA Intern Med. 2021 Oct 11.

Links:

COVID-19 Research (NIH)

Peter Nordström (Umeå University, Sweden)

Credit: Say Yes! COVID Test

With most kids now back in school, parents face a new everyday concern: determining whether their child’s latest cough or sneeze might be a sign of COVID-19. If so, parents will want to keep their child at home to protect other students and staff, while also preventing the spread of the virus in their communities. And if it’s the parent who has a new cough, they also will want to know if the reason is COVID-19 before going to work or the store.

Home tests are now coming online to help concerned people make the right choice quickly. As more COVID-19 home tests enter the U.S. marketplace, research continues to help optimize their use. That’s why NIH and the Centers for Disease Control and Prevention (CDC) are teaming up in several parts of the country to provide residents age 2 and older with free home-testing kits for COVID-19. These reliable, nasal swab tests provide yes-or-no answers in about 15 minutes for parents and anyone else concerned about their possible exposure to the novel coronavirus.

The tests are part of an initiative called Say Yes! COVID Test (SYCT) that’s evaluating how best to implement home-testing programs within range of American communities, both urban and rural. The lessons learned are providing needed science-based data to help guide public health officials who are interested in implementing similar home-testing programs in communities throughout their states.

After successful eight-week pilot programs this past spring and summer in parts of North Carolina, Tennessee, and Michigan, SYCT is partnering this fall with four new communities. They are Fulton County, Georgia and Honolulu County, Hawaii, along with other communities in the South and in the Midwest that will be announced later this month.

The Georgia and Hawaii partnerships, launched on September 20, are already off to a flying start. In Fulton County, home to Atlanta and several small cities, 21,673 direct-to-consumer orders (173,384 tests) have already been received. In Honolulu County, demand for the tests has exceeded all expectations, with 91,000 orders received in the first week (728,000 tests). The online ordering has now closed in Hawaii, and the remaining tests will be distributed on the ground through the local public health department.

SYCT offers the Quidel QuickVue® At-Home COVID-19 test, which is supplied through the NIH Rapid Acceleration of Diagnostics (RADx) initiative. The antigen test uses a self-collected nasal swab sample that is placed in a test tube containing solution, followed by a test strip. Colored lines that appear on the test strip indicate a positive or negative result—similar to a pregnancy test.

The program allows residents in participating counties to order free home tests online or for in-person pick up at designated sites in their community. Each resident can ask for eight rapid tests, which equals two weekly tests over four weeks. An easy-to-navigate website like this one and a digital app, developed by initiative partner CareEvolution, are available for residents to order their tests, sign-up for testing reminders, and allow voluntary test result reporting to the public health department.

SYCT will generate data to answer several important questions about self or home-testing. They include questions about consumer demand, ensuring full community access, testing behavior, willingness to report test results, and, above all, effectiveness in controlling the spread of SARS-CoV-2, the coronavirus that causes COVID-19

Researchers at the University of North Carolina-Chapel Hill; Duke University, Durham, NC; and the University of Massachusetts, Amherst, will help crunch the data and look for guiding themes. They will also conduct a study pre- and post-intervention to evaluate levels of SARS-CoV-2 in the community, including using measures of virus in wastewater. In addition, researchers will compare their results to other counties similar in size and infection rates, but that are not participating in a free testing initiative.

The NIH and CDC are exploring ways to scale a SYCT-like program nationally to communities experiencing surges in COVID-19. The Biden Administration also recently invoked the Defense Production Act to purchase millions of COVID-19 home tests to help accelerate their availability and offer them at a lower cost to more Americans. That encompasses many different types of people, including concerned parents who need a quick-and-accurate answer on whether their children’s cough or sneeze is COVID-19.

Links:

COVID-19 Research (NIH)

Say Yes! COVID TestRapid Acceleration of Diagnostics (RADx) (NIH)

NIH Support: National Institute of Biomedical Imaging and Bioengineering; National Heart, Lung, and Blood Institute; National Institute on Minority Health and Health Disparities

Credit: fizkes/Shutterstock; adapted from Siegler, JAMA Netw Open. 2021

As long and difficult as this pandemic has been, I remain overwhelmingly grateful for the remarkable progress being made, including the hard work of so many people to develop rapidly and then deploy multiple life-saving vaccines. And yet, grave concerns remain that vaccine hesitancy—the reluctance of certain individuals and groups to get themselves and their children vaccinated—could cause this pandemic to go on much longer than it should.

We’re seeing the results of such hesitancy in the news every day, highlighting the rampant spread of COVID-19 that’s stretching our healthcare systems and resources dangerously thin in many places. The vast majority of those currently hospitalized with COVID-19 are unvaccinated, and most of those tragic 2,000 deaths each day could have been prevented. The stories of children and adults who realized too late the importance of getting vaccinated are heartbreaking.

With these troubling realities in mind, I was encouraged to see a new study in the journal JAMA Network Open that tracked vaccine hesitancy over time in a random sample of more than 4,600 Americans. This national study shows that vaccine hesitancy isn’t set in stone. Over the course of this pandemic, hesitancy has decreased, and many who initially said no are now getting their shots. Many others who remain unvaccinated lean toward making an appointment.

The findings come from Aaron Siegler and colleagues, Emory University, Atlanta. They were interested in studying how entrenched vaccine hesitancy would be over time. The researchers also wanted to see how often those who were initially hesitant went on to get their shots.

To find out, they recruited a diverse, random, national sampling of individuals from August to December 2020, just before the first vaccines were granted Emergency Use Approval and became widely available. They wanted to get a baseline, or starting characterization, on vaccine hesitancy. Participants were asked two straightforward questions, “Have you received the COVID-19 vaccine?” and “How likely are you to get it in the future?” From March to April 2021, the researchers followed up by asking participants the same questions again when vaccines were more readily available to many (although still not all) adults.

The survey’s initial results showed that nearly 70 percent of respondents were willing to get vaccinated at the outset, with the other 30 percent expressing some hesitancy. The good news is among the nearly 3,500 individuals who answered the survey at follow-up, about a third who were initially vaccine hesitant already had received at least one shot. Another third also said that they’d now be willing to get the vaccine, even though they hadn’t just yet.

Among those who initially expressed a willingness to get vaccinated, about half had done so at follow up by spring 2021 (again, some still may not have been eligible). Forty percent said they were likely to get vaccinated. However, 7 percent of those who were initially willing said they were now less likely to get vaccinated than before.

There were some notable demographic differences. Folks over age 65, people who identified as non-Hispanic Asians, and those with graduate degrees were most likely to have changed their minds and rolled up their sleeves. Only about 15 percent in any one of these groups said they weren’t willing to be vaccinated. Most reluctant older people ultimately got their shots.

The picture was more static for people aged 45 to 54 and for those with a high school education or less. The majority of those remained unvaccinated, and about 40 percent still said they were unlikely to change their minds.

At the outset, people of Hispanic heritage were as willing as non-Hispanic whites to get vaccinated. At follow-up, however, fewer Hispanics than non-Hispanic whites said they’d gotten their shots. This finding suggests that, in addition to some hesitancy, there may be significant barriers still to overcome to make vaccination easier and more accessible to certain groups, including Hispanic communities from Central and South America.

Willingness among non-Hispanic Blacks was consistently lowest, but nearly half had gotten at least one dose of vaccine by the time they completed the second survey. That’s comparable to the vaccination rate in white study participants. For more recent data on vaccination rates by race/ethnicity, see this report from the Kaiser Family Foundation.

Overall, while a small number of respondents grew more reluctant over time, most people grew more comfortable with the vaccines and were more likely to say they’d get vaccinated, if they hadn’t already. In fact, by the end of the study, the hesitant group had shrunk from 31 to 15 percent. It’s worth noting that the researchers checked the validity of self-reported vaccination using antibody tests and the results matched up rather well.

This is all mostly good news, but there’s clearly more work to do. An estimated 70 million eligible Americans have yet to get their first shot, and remain highly vulnerable to infection and serious illness from the Delta variant. They are capable of spreading the virus to other vulnerable people around them (including children), and incubating the next variants that might provide more resistance to the vaccines and therapies. They are also at risk for Long COVID, even after a relatively mild acute illness.

The work ahead involves answering questions and addressing concerns from people who remain hesitant. It’s also incredibly important to reach out to those willing, but unvaccinated, individuals, to see what can be done to help them get their shots. If you happen to be one of those, it’s easy to find the places near you that have free vaccines ready to administer. Go to vaccines.gov, or punch 438829 on your cell phone and enter your zip code—in less than a minute you will get the location of vaccine sites nearby.

Nearly 400 million COVID-19 vaccine doses have been administered in communities all across the United States. More than 600,000 more are being administered on average each day. And yet, more than 80,000 new infections are still reported daily, and COVID-19 still steals the lives of about 2,000 mostly unvaccinated people each day.

These vaccines are key for protecting yourself and ultimately beating this pandemic. As these findings show, the vast majority of Americans understand this and either have been vaccinated or are willing to do so. Let’s keep up the good work, and see to it that even more minds will be changed—and more individuals protected before they may find it’s too late.

Reference:

[1] Trajectory of COVID-19 vaccine hesitancy over time and association of initial vaccine hesitancy with subsequent vaccination. Siegler AJ, Luisi N, Hall EW, Bradley H, Sanchez T, Lopman BA, Sullivan PS. JAMA Netw Open. 2021 Sep 1;4(9):e2126882.

Links:

COVID-19 Research (NIH)

COVID-19 Vaccinations in the United States (Centers for Disease Control and Prevention, Atlanta)

Aaron Siegler (Emory University, Atlanta)

NIH Support: National Institute for Allergy and Infectious Diseases

More than 180 million Americans, including more than 80 percent of people over age 65, are fully vaccinated against the SARS-CoV-2 virus responsible for COVID-19. There’s no question that full vaccination is the best way to protect yourself against this devastating virus and reduce your chances of developing severe or long-lasting illness if you do get sick. But, to stay ahead of this terrible virus, important questions do remain. A big one right now is: How soon will booster shots be needed and for whom?

The answers to this question will continue to evolve as more high-quality data become available. But here’s what we know right now for the Pfizer-BioNTech booster. Late last week, Dr. Rochelle Walensky, the Director of the Centers for Disease Control and Prevention (CDC), recommended that:

Those 65 years and older and residents in long-term care settings should receive a booster shot at least 6 months after being fully vaccinated with the Pfizer-BioNTech vaccine,People aged 50–64 years with underlying medical conditions should receive a booster shot at least 6 months after being fully vaccinated with the Pfizer-BioNTech vaccine,Individuals aged 18–49 years with underlying medical conditions may receive a booster shot at least 6 months after getting fully vaccinated with their Pfizer-BioNTech vaccine, based on their individual benefits and risks.Frontline workers who received the Pfizer-BioNTech vaccine may receive a booster. This group includes anyone age 18 through 64 whose frequent institutional or occupational exposure to SARS-CoV-2 puts them at high risk of COVID-19. [1]

Taken together, these CDC recommendations are in line with those issued two days earlier by the Food and Drug Administration (FDA) [2].

Some of the most-compelling data that was under review came from an Israeli study, published recently in the New England Journal of Medicine, that explored the benefit of booster shots for older people [3]. Israel, with a population of around 9 million, has a national health system and one of the world’s highest COVID-19 vaccination rates. That country’s vaccination campaign, based solely on Pfizer-BioNTech, was organized early in 2021, and so its experience is about three months ahead of ours here in the U.S. These features, plus some of the world’s largest integrated health record databases, have made Israel an important source of early data on how the Pfizer-BioNTech mRNA vaccine can be expected to work in the real world over time.

Earlier this year, Israeli public health officials noted evidence for an increased number of breakthrough infections, some of which were severe. So, at the end of July 2021, Israel approved the administration of third doses, or “boosters,” of the Pfizer-BioNTech vaccine for people ages 60 and up who had received their second dose at least five months before.

To find out how well these booster shots worked to bolster immune protection against COVID-19, researchers looked to more than 1.1 million fully vaccinated people who were at least 60 years old. They compared the rate of confirmed COVID-19 infection and severe illness from the end of July to the end of August among people who’d received a booster at least 12 days earlier with those who hadn’t gotten boosters.

Nearly 13,500 older individuals who’d been fully vaccinated before March 2021, got a breakthrough infection during the two months of study. Importantly, the rate of confirmed infection in the group that got boosters was 10 times lower on average than in the group that didn’t get boosters. The data on severe illness looked even better. Of course, there could be other factors at play that weren’t accounted for in the study, but the findings certainly suggest that a third Pfizer shot is safe and effective for older people.

Though the Israeli studies on booster shots are a little ahead of the international pack, we are starting to see results from the research underway in the U.S. Last week, for example, Johnson & Johnson announced new data in support of boosters to improve and extend immune protection in those who received its single-dose COVID-19 vaccine [4]. For people who received the Moderna mRNA vaccine, the company has already submitted its data to the FDA for booster authorization. A decision is expected soon.

As the critical evidence on boosters continues to emerge, the most important way to avoid another winter surge of COVID-19 is to follow all public health recommendations. Most importantly, that includes getting fully vaccinated if you haven’t already, and encouraging others around you to do the same. If you’re currently eligible for a booster shot, they are available at 80,000 locations across the nation, and can help you stay healthy and well for the coming holiday season.

For others eager to do everything possible to protect themselves, their families, and their communities against this terrible virus—but who are not yet eligible for a booster—sit tight for now. The data on booster shots are still coming in for folks like me who were immunized with the Moderna or Johnson & Johnson vaccines. It’s likely that the FDA and CDC will widen their recommendations in the coming weeks.

In the meantime, the Delta variant is still out there and circulating. That makes it critical to maintain vigilance. Wear a mask in indoor spaces, keep a physical distance from others, and remember to wash your hands frequently. We are all really tired of COVID-19, but patience is still required as we learn more about how best to stay ahead of this virus.

References:

[1] CDC statement on ACIP booster recommendations. Centers for Disease Control and Prevention news release. September 24, 2021

[2] FDA authorizes booster dose of Pfizer-BioNTech COVID-19 vaccine for certain populations. Food and Drug Administration news release. September 22, 2021

[3] Protection of BNT162b2 vaccine booster against Covid-19 in Israel. Bar-On YM, Goldberg Y, Mandel M, Bodenheimer O, Freedman L, Kalkstein N, Mizrahi B, Alroy-Preis S, Ash N, Milo R, Huppert A. N Engl J Med. 2021 Sep 15.

[4] Johnson & Johnson announces real-world evidence and Phase 3 data confirming strong and long-lasting protection of single-shot COVID-19 vaccine in the U.S. Johnson & Johnson. September 21, 2021.

Links:

COVID-19 Research (NIH)

Credit: Camille L.L. Townshend

Researchers recently showed that a computer could “learn” from many examples of protein folding to predict the 3D structure of proteins with great speed and precision. Now a recent study in the journal Science shows that a computer also can predict the 3D shapes of RNA molecules [1]. This includes the mRNA that codes for proteins and the non-coding RNA that performs a range of cellular functions.

This work marks an important basic science advance. RNA therapeutics—from COVID-19 vaccines to cancer drugs—have already benefited millions of people and will help many more in the future. Now, the ability to predict RNA shapes quickly and accurately on a computer will help to accelerate understanding these critical molecules and expand their healthcare uses.

Like proteins, the shapes of single-stranded RNA molecules are important for their ability to function properly inside cells. Yet far less is known about these RNA structures and the rules that determine their precise shapes. The RNA elements (bases) can form internal hydrogen-bonded pairs, but the number of possible combinations of pairings is almost astronomical for any RNA molecule with more than a few dozen bases.

In hopes of moving the field forward, a team led by Stephan Eismann and Raphael Townshend in the lab of Ron Dror, Stanford University, Palo Alto, CA, looked to a machine learning approach known as deep learning. It is inspired by how our own brain’s neural networks process information, learning to focus on some details but not others.

In deep learning, computers look for patterns in data. As they begin to “see” complex relationships, some connections in the network are strengthened while others are weakened.

One of the things that makes deep learning so powerful is it doesn’t rely on any preconceived notions. It also can pick up on important features and patterns that humans can’t possibly detect. But, as successful as this approach has been in solving many different kinds of problems, it has primarily been applied to areas of biology, such as protein folding, in which lots of data were available for researchers to train the computers.

That’s not the case with RNA molecules. To work around this problem, Dror’s team designed a neural network they call ARES. (No, it’s not the Greek god of war. It’s short for Atomic Rotationally Equivariant Scorer.)

To start, the researchers trained ARES on just 18 small RNA molecules for which structures had been experimentally determined. They gave ARES these structural models specified only by their atomic structure and chemical elements.

The next test was to see if ARES could determine from this small training set the best structural model for RNA sequences it had never seen before. The researchers put it to the test with RNA molecules whose structures had been determined more recently.

ARES, however, doesn’t come up with the structures itself. Instead, the researchers give ARES a sequence and at least 1,500 possible 3D structures it might take, all generated using another computer program. Based on patterns in the training set, ARES scores each of the possible structures to find the one it predicts is closest to the actual structure. Remarkably, it does this without being provided any prior information about features important for determining RNA shapes, such as nucleotides, steric constraints, and hydrogen bonds.

It turns out that ARES consistently outperforms humans and all other previous methods to produce the best results. In fact, it outperformed at least nine other methods to come out on top in a community-wide RNA-puzzles contest. It also can make predictions about RNA molecules that are significantly larger and more complex than those upon which it was trained.

The success of ARES and this deep learning approach will help to elucidate RNA molecules with potentially important implications for health and disease. It’s another compelling example of how deep learning promises to solve many other problems in structural biology, chemistry, and the material sciences when—at the outset—very little is known.

Reference:

[1] Geometric deep learning of RNA structure. Townshend RJL, Eismann S, Watkins AM, Rangan R, Karelina M, Das R, Dror RO. Science. 2021 Aug 27;373(6558):1047-1051.

Links:

Structural Biology (National Institute of General Medical Sciences/NIH)

The Structures of Life (National Institute of General Medical Sciences/NIH)

RNA Biology (NIH)

RNA Puzzles

Dror Lab (Stanford University, Palo Alto, CA)

NIH Support: National Cancer Institute; National Institute of General Medical Sciences

There’s no question that vaccines are making a tremendous difference in protecting individuals and whole communities against infection and severe illness from SARS-CoV-2, the coronavirus that causes COVID-19. And now, there’s yet another reason to get the vaccine: in the event of a breakthrough infection, people who are fully vaccinated also are substantially less likely to develop Long COVID Syndrome, which causes brain fog, muscle pain, fatigue, and a constellation of other debilitating symptoms that can last for months after recovery from an initial infection.

These important findings published in The Lancet Infectious Diseases are the latest from the COVID Symptom Study [1]. This study allows everyday citizens in the United Kingdom to download a smartphone app and self-report data on their infection, symptoms, and vaccination status over a long period of time.

Previously, the study found that 1 in 20 people in the U.K. who got COVID-19 battled Long COVID symptoms for eight weeks or more. But this work was done before vaccines were widely available. What about the risk among those who got COVID-19 for the first time as a breakthrough infection after receiving a double dose of any of the three COVID-19 vaccines (Pfizer, Moderna, AstraZeneca) authorized for use in the U.K.?

To answer that question, Claire Steves, King’s College, London, and colleagues looked to frequent users of the COVID Symptom Study app on their smartphones. In its new work, Steves’ team was interested in analyzing data submitted by folks who’d logged their symptoms, test results, and vaccination status between December 9, 2020, and July 4, 2021. The team found there were more than 1.2 million adults who’d received a first dose of vaccine and nearly 1 million who were fully vaccinated during this period.

The data show that only 0.2 percent of those who were fully vaccinated later tested positive for COVID-19. While accounting for differences in age, sex, and other risk factors, the researchers found that fully vaccinated individuals who developed breakthrough infections were about half (49 percent) as likely as unvaccinated people to report symptoms of Long COVID Syndrome lasting at least four weeks after infection.

The most common symptoms were similar in vaccinated and unvaccinated adults with COVID-19, and included loss of smell, cough, fever, headaches, and fatigue. However, all of these symptoms were milder and less frequently reported among the vaccinated as compared to the unvaccinated.

Vaccinated people who became infected were also more likely than the unvaccinated to be asymptomatic. And, if they did develop symptoms, they were half as likely to report multiple symptoms in the first week of illness. Another vaccination benefit was that people with a breakthrough infection were about a third as likely to report any severe symptoms. They also were more than 70 percent less likely to require hospitalization.

We still have a lot to learn about Long COVID, and, to get the answers, NIH has launched the RECOVER Initiative. The initiative will study tens of thousands of COVID-19 survivors to understand why many individuals don’t recover as quickly as expected, and what might be the cause, prevention, and treatment for Long COVID.

In the meantime, these latest findings offer the encouraging news that help is already here in the form of vaccines, which provide a very effective way to protect against COVID-19 and greatly reduce the odds of Long COVID if you do get sick. So, if you haven’t done so already, make a plan to protect your own health and help end this pandemic by getting yourself fully vaccinated. Vaccines are free and available near to you—just go to vaccines.gov or text your zip code to 438829.

Reference:

[1] Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID Symptom Study app: a prospective, community-based, nested, case-control study. Antonelli M, Penfold RS, Merino J, Sudre CH, Molteni E, Berry S, Canas LS, Graham MS, Klaser K, Modat M, Murray B, Kerfoot E, Chen L, Deng J, Österdahl MF, Cheetham NJ, Drew DA, Nguyen LH, Pujol JC, Hu C, Selvachandran S, Polidori L, May A, Wolf J, Chan AT, Hammers A, Duncan EL, Spector TD, Ourselin S, Steves CJ. Lancet Infect Dis. 2021 Sep 1:S1473-3099(21)00460-6.

Links:

COVID-19 Research (NIH)

Claire Steves (King’s College London, United Kingdom)

COVID Symptom Study