Following another week of surging Covid-19 infections — including early data suggesting a rise in breakthrough cases among those who are fully vaccinated — the Biden administration announced their recommendation of a booster vaccine shot in a statement from the U.S. Department of Health and Human Services (HHS) on August 18th. This announcement comes less than a week after the Centers for Disease Control and Prevention (CDC) recommendation that people who are moderately to severely immunocompromised receive an additional dose of an mRNA vaccine (Pfizer-BioNTech or Moderna) took effect.
Citing mounting concerns over the highly infectious Delta variant, as well as new data indicating a decrease in protection from the vaccine over time, the White House is advising a booster shot eight months after a person’s second dose of the Pfizer-BioNTech or Moderna vaccines, starting September 20th. (A recommendation for booster shots for those who received the Johnson & Johnson vaccine will likely follow, once the clinical-trial findings are available.)
But while the White House booster policy itself isn’t unexpected, the specific timing of the announcement is, given that neither the CDC nor Food and Drug Administration (FDA) has yet issued guidance or authorization for the use of any Covid vaccine booster candidates in the general population. At a briefing on Wednesday afternoon, the White House Covid-19 Task Force addressed this, as well as other aspects of the Biden administration’s decision. Here’s what we now know about Covid vaccine boosters, as well as some of the questions that still remain.
A recommendation made out of sequence
When White House plans to recommend Covid-19 vaccine boosters first came to light in a New York Times article published late on Monday, August 16th, it left some health-policy experts surprised and confused. For an administration that prides itself on listening to the science and following the data, the recommendation seemed premature, given that the relevant data were conspicuously missing.
Over the past few months, CDC and White House officials have said — repeatedly — that they would not recommend a Covid vaccine booster for the general public without convincing empirical evidence demonstrating that one is necessary. But aside from a few references to emerging data from Israel in Monday night’s article, between its publication and the HHS statement issued Wednesday morning, no such data were made publicly available.
Adding to the confusion was the fact that the Biden administration’s recommendation came before the CDC’s Advisory Committee on Immunization Practices (ACIP) had a chance to weigh in on this specific use of Covid vaccine boosters, as well as FDA Emergency Use Authorization (EUA) for a single booster candidate.
So what changed? For starters, increasingly clear trends emerging from the data after long-term analysis.
While members of the Covid-19 Task Force used Wednesday’s briefing to highlight some of the newly published data — making a clear case for why now is the time to recommend Covid vaccine boosters — a CDC press officer stressed that data monitoring and evaluation has been ongoing. “We have been reviewing the science and data on a near daily basis to evaluate whether or when boosters may be needed,” a CDC spokesperson said in a statement emailed to Rolling Stone on August 17th.
Similarly, a press officer for the FDA emphasized that the agency, along with the CDC and National Institutes of Health (NIH), have been “engaged in a science-based, rigorous process to consider when boosters might be necessary.” More specifically, a “process [that] takes into account laboratory data, clinical trial data, and cohort data — which can include data from specific pharmaceutical companies, but does not rely on those data exclusively,” a spokesperson for the FDA said in an August 17th statement to Rolling Stone. In other words, the Biden administration did not reach their decision to recommend Covid vaccine boosters overnight.
The data that sealed the deal
At the beginning of Wednesday’s press briefing, Surgeon General Dr. Vivek Murthy, speaking on behalf of the other members of the Covid-19 Task Force, explained that after reviewing the most current data, “it is now our clinical judgment that the time to lay out a plan for Covid-19 boosters is now.” Noting that the current Covid-19 vaccines have been “remarkably effective, even against the widespread Delta variant,” Murthy explained that “even highly effective vaccines become less effective over time.”
As CDC Director Dr. Rochelle Walensky indicated during the briefing, much of the data that informed the booster recommendation came from three recent studies, which together offer three major takeaways. “First, vaccine-induced protection against SARS-CoV-2 infection begins to decrease over time,” Walensky said. “Second, vaccine effectiveness against severe disease, hospitalization, and death remains relatively high. And third, vaccine effectiveness is generally decreased against the Delta variant.”
Using data from New York state’s vaccine records — which includes more than 10 million residents of all ages — one study (published on Wednesday) found that between May 3rd and July 25th, the Covid vaccine gradually became less effective: preventing 92 percent of new infections in May, then falling to 80 percent by the end of July. But the good news is that during the same period, the effectiveness of the vaccine against infections that lead to hospitalization remained relatively stable, hovering between 92 and 95 percent.
The second study analyzed data collected from more than 80,000 people of varying ages across multiple Mayo Clinic Health System sites. “Like we saw in the New York data, vaccine effectiveness against infection declined over time — in this case, from 76 percent to 42 percent for those who received the Pfizer vaccine, and from 86 percent to 76 percent for those who received the Moderna vaccine,” Walensky said.
Finally, the remaining study (also published on Wednesday) looked at vaccine effectiveness against new Covid infections among nursing home residents, finding that it dropped from 75 percent in March to 53 percent in August. “Taken together,” Walensky said, “these data confirm that while protection against infection may decrease over time, protection against severe disease and hospitalization is currently holding up pretty well.”
So will boosters help slow the spread of SARS-CoV-2 — particularly, the Delta variant? According to Chief Medical Advisor to the President and Director of the National Institute of Allergy and Infectious Diseases (NIAID) Dr. Anthony Fauci, “it is entirely conceivable” that the boosters could help reduce the amount of virus in the bottom of a person’s nasal cavity, which in turn could have an impact on transmission. “I certainly hope that’s the case,” he said at Wednesday’s briefing. “If it is, then you could really get multiple benefits from doing this. You can get benefits for disease, severity of disease, and then, ultimately, infection and transmission. But the bottom line, with full transparency: We don’t know that right now.”
Considering the booster candidates
Along with data on the duration of a vaccine’s effectiveness, and the number and severity of breakthrough cases, a recommendation for boosters also requires strong evidence demonstrating why these additional doses will likely help, and which candidates are best suited for the job.
Based on what we know about vaccines in general, both in terms of immunity waning over time, and the challenges of emerging viral variants, the need for a Covid-19 vaccine booster shot is in no way unexpected. That’s why a variety of clinical trials looking into the safety and efficacy of different formulations and combinations of boosters have been underway for months. At this point, the only available findings come from studies conducted by mRNA vaccine manufacturers, Pfizer-BioNTech and Moderna, which (along with promising initial data) is likely why the companies’ boosters were the ones included in the White House recommendations.
At Wednesday’s briefing, Fauci shared some up-to-date immunological data supporting a booster mRNA immunization. In short, the Covid-19 antibodies we acquire through the vaccine decline over time. This isn’t ideal, considering that higher antibody levels are associated with higher vaccine efficacy, and that they may be needed to offer protection against the Delta variant. But it’s not all negative: data from Pfizer and Moderna indicate that getting a booster mRNA vaccine increased a person’s antibody levels “by at least tenfold,” Fauci said.
But those who received the Johnson & Johnson vaccine haven’t been forgotten. According to Murthy, the Covid-19 Task Force anticipates that J&J boosters will be needed, but because the vaccine wasn’t not administered in the U.S. until March, the data is not expected for a few weeks.
Around the same time, the initial findings should be available from an NIH-sponsored multicenter clinical trial testing various combinations of dosages and boosters from all three major manufacturers. (So for example, someone who initially received the Johnson & Johnson vaccine may get a Moderna booster, and vice versa.) Referred to as the “mix and match study,” the goal of the research extends beyond testing the safety and efficacy of multiple booster candidates, and aims to pinpoint the ones likely to produce the best results — as well as which (if any) should be avoided.
According to Dr. Kirsten Lyke, professor of medicine at the University of Maryland School of Medicine and co-principal investigator of the NIH mix and match study, there will be “some really good, hard data” available from the clinical trial as soon as early September. And unlike Pfizer and Moderna’s in-house booster studies, she says that the NIH trial is “agnostic to the company” — in other words, the resulting data isn’t a step towards seeking FDA licensure for a booster.
“We don’t have any skin in the game, in terms of which [booster candidate] is better than another,” Lyke tells Rolling Stone. “We’re just looking at everything on an equal footing.” For now, it remains to be seen whether getting a third dose of either the Pfizer or Moderna vaccine — per Biden administration recommendations — will end up being the booster regimen with the best results. But at least for the time being, they are safe and effective options.
The CDC and FDA still have to weigh in on booster candidates
One of the more surprising aspects of Monday’s announcement was that a Covid-vaccine-related recommendation would come from the White House ahead of the FDA issuing EUA for at least one booster shot, and any guidance from the CDC’s vaccine advisory committee. Though the Times article did note that the recommendation was contingent upon both FDA and CDC review, typically, high-level policy announcements like this aren’t made before both agencies issue their stamp of approval.
But at Wednesday’s briefing, Murthy stressed that White House recommendation isn’t ignoring protocol. “I want to be very clear: We are not skipping the very important FDA and ACIP process here,” he said. “They have an incredibly important role to play in evaluating safety and making recommendations for vaccines. We respect that, we honor that and that will be a part of this process as well.”
FDA authorization and CDC approval may not be far off. On Monday, Pfizer-BioNTech announced that they had submitted Phase 1 data from a clinical trial evaluating a third dose of their current Covid-19 vaccine. And earlier this month, Moderna issued a statement noting that their booster candidates “demonstrate robust antibody responses to COVID-19 variants of concern,” though the company has not yet submitted their data for FDA authorization.
The case for making the booster recommendation now
With more clinical trial data about to roll in, and initial results from Pfizer’s booster study currently under review by the FDA, why did the White House opt to announce their recommendation for Covid vaccine booster shots now?
According to Murthy, it’s a matter of transparency and preparation, with a view to getting booster shots in arms in a timely and efficient way. “We also want to ensure that people and states and localities and the public more broadly can plan,” he explained at the briefing. “You can’t turn on a booster effort with the flip of a switch. You have to lay the groundwork.”
Earlier in the briefing, White House Covid-19 Response Coordinator Jeff Zients explained that the Biden administration has been preparing for every pandemic scenario for months, including one where boosters are required. “Our approach on booster shots is simple, and it’s consistent with our approach on every other front of this war: Be guided by the science, and always, always stay one step ahead of the virus,” he said.
A few hours after the White House briefing, President Joe Biden offered some remarks echoing Zients’ messaging, including telling those who are fully vaccinated to “know that you’re highly protected against severe illness and death from Covid-19,” and that his administration has “a responsibility to give [people] the maximum amount of protection” — which, according to the latest data, means offering booster shots.
What boosters for Americans means for global vaccine equity
Ever since news of the impressive safety and efficacy rates of Pfizer-BioNTech and Moderna’s Covid vaccines was first reported in November 2020, there has been widespread concern over what a U.S.-centric rollout strategy would mean for people living in other parts of the world — especially regions where it’s a challenge to access healthcare and other basic resources. Now, eight months later, only 1.3 percent of people living in low-income countries have received at least one dose of a Covid vaccine, according to a dataset maintained by the University of Oxford.
That’s why, at an August 4th press briefing, World Health Organization (WHO) Director-General Dr. Tedros Adhanom Gebreyesus called for a moratorium on Covid booster shots until “at least the end of September,” with the goal of getting at least 10 percent of people in every country of the world vaccinated before then. “Some rich countries are considering booster doses even though there are hundreds of millions of people waiting to have access to a first dose,” he added.
And while technically, the Biden administration’s plans to begin the booster vaccine rollout the week of September 20th may adhere to the WHO’s proposed moratorium timeline and pass as “the end of September,” for many, it’s a question of equity. Namely, whether it’s ethical to start giving Americans boosters before so much of the world’s population has even gotten their first dose of a vaccine.
The subject came up during the White House briefing and Biden’s remarks later in the day, both of which provided the same rationale. First, Murthy addressed the question of how initiating a Covid vaccine booster rollout in the United States could impact vaccine supply for the rest of the world.
“Look, I do not accept the idea that we have to choose between America and the world,” he said. “We clearly see our responsibility to both, and that we’ve got to do everything we can to protect people here at home, while recognizing that clamping down [on] the pandemic across the world, and getting people vaccinated is going to be key to preventing the rise of future variants.”
Later that day, Biden made his stance clear. “Now, I know there are some world leaders who say Americans shouldn’t get a third shot until other countries get their first shots. I disagree,” the president said, making the case that “we can take care of America and help the world at the same time.” Biden then invoked his analogy comparing the Covid-19 pandemic to a war:
“As I said before, we’re going to be the arsenal of vaccines to beat this pandemic, as we were the arsenal of democracy to win World War II.”
And what has come from this arsenal so far? According to figures cited by Biden and Zients, 50 million shots of Covid vaccine were administered in the U.S. in June and July, with an additional 100 million shots shipped to other parts of the world during that period. At present, more than 115 million doses have been sent to 80 different countries, according to Zients. “That means that America has donated more vaccine to other countries than every other country in the world combined,” Biden said, reaffirming his pledge to eventually provide more than 600 million vaccine donations worldwide.
The rollout should be smoother this time
Remember the dystopian nightmare of attempting to book a Covid vaccine in the first few months of 2021? (You know, the one that came before our current dystopian nightmare where we literally can’t pay people to get vaccinated?) Well, according to Zients, this time will be different, noting that “we have enough vaccine supply for every American” and that “it will be just as easy and convenient to get a booster shot as it is to get the first shot today,” thanks to the roughly 80,000 vaccination sites across the country, including more than 40,000 local pharmacies.
The entire process is designed to be significantly simpler and more straightforward than the initial rollout, and like the first doses, boosters will also be free. “It will be easy,” Biden assured the country during his Wednesday afternoon remarks. “Just show your vaccination card and you’ll get a booster. No other ID. No insurance. No state residency requirement.” The president concluded his case for Covid vaccine boosters by emphasizing the benefits of the shot. “It will make you safer and for longer,” he said. “And it will help us end the pandemic faster.”