Are boosters meant to prevent infections? Or to keep people out of the hospital?
As the U.S. heads into the winter months, the nation’s top vaccine experts and infectious disease physicians are torn over whether the majority of the general public needs Covid vaccine booster shots.
Some believe that the primary goal should be to prevent severe disease from Covid-19. Others, including Dr. Anthony Fauci, director of the National Institute for Allergy and Infectious Disease, argue that the goal of vaccination should be to not only prevent severe disease and hospitalization but also milder forms of the illness, as well as infection.
“There appears to be a bit of a twisted narrative that it doesn't matter if you get infected, get mild or moderate disease, are in bed at home, recover and then get long Covid,” Fauci said in an interview with NBC News, adding that some say “it’s all right as long as you don't get hospitalized, which I think is a bit misleading.”
For Fauci, preventing infection is important for protecting people against unpleasant, often lingering symptoms and disruptions in daily life.
“Would you feel comfortable getting infected, being in bed and missing your work for a couple weeks and then feeling fatigued for the next three, four or five weeks?” he asked. “Would you like that? I don't think so.”
Fauci also added that while protection against severe illness appears to be holding steady in the United States, data emerging from Israel suggests there is a clear benefit to preventing severe disease in those over 40.
Dr. Paul Offit, a vaccine researcher at Children's Hospital of Philadelphia and member of the Food and Drug Administration’s vaccine advisory panel, disagrees, arguing instead that the goal of the Covid vaccines should be to prevent serious illness that results in hospitalization.
“If that's the goal of this vaccine, that goal has been met so far,” he said.
Communication around what the purpose of the vaccine should be could be better, Offit said. He is frustrated with the term “breakthrough infection,” used to describe a positive test in a vaccinated individual.
“I think the biggest communication error that has been made is using the term ‘breakthrough’ to define asymptomatic or mildly symptomatic [infection],” he said. “That's a win. The term breakthrough implies failure. This is not a failure.”
Offit says that the adults he sees coming into the ICU these days are not there because they haven’t gotten their booster but because they haven’t been vaccinated at all.
Last week, the FDA vaccine advisory panel recommended additional doses of the Moderna and Johnson and Johnson vaccines to protect against waning immunity, which means millions more Americans will be eligible for booster shots in the coming days.
According to data from the Centers for Disease Control and Prevention, almost 11 million people in the United States have already received their booster doses.
While evidence from the vaccine makers presented to the FDA indicates that the extra doses do raise antibody levels and appear to be safe, some experts are concerned about the potential risks of a rare heart condition, especially for younger men.
The condition, called myocarditis, occurs when there is inflammation of the heart muscle and has been linked to both the Pfizer-BioNTech and Moderna vaccines. Fortunately, the condition remains rare and most cases are mild and get better with treatment.
There’s little data about myocarditis cases among those who have received a third dose of a vaccine in the U.S. Because of this, federal health agencies are looking to research from Israel to see if there is an increased risk.
That data shows a very low risk — for males 16 to 19 years old, there are 11 confirmed cases of myocarditis out of approximately 370,000 people who received a third dose of the Pfizer vaccine. That’s lower than what was seen after the second dose, where there were 82 cases of myocarditis out of approximately 714,000 people.
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Dr. Jake Scott, an infectious disease physician at Stanford University Medical Center, said that some young health care workers he knows who are eligible for a booster have expressed concerns.
“Many health care workers I know have expressed reluctance to get the third dose because they feel like they're at risk for myocarditis and they don’t think they are at risk for complications from Covid since they are fully vaccinated,” Scott said. “I totally understand that.”
One argument for boosters for the general public is that they will help reduce community transmission, leading to the virus circulating less and decreased case counts.
However, Scott said it's unclear at this time if booster doses are going to make any meaningful impact on transmission.
“There isn't enough long-term epidemiologic data yet to really support the use of additional doses of vaccines for the sake of impacting transmission on a population level,” he said.
Scott said that while nobody would argue that boosters don’t increase antibody levels, he wonders how long that response will last and if it will be significant enough to really affect the epidemiology of Covid-19.
As far as the safety of a third dose is concerned, Scott isn’t too worried in groups who stand to benefit the most from a third dose, including those over 65 and those with compromised immune systems.
Right now, it remains to be seen whether those who have had a confirmed case of Covid-19 and been fully vaccinated stand to benefit much from a third dose. More than 44 million Americans have had Covid, and there are undoubtedly many undiagnosed cases beyond that.
That remains an “unanswered question” that needs to be studied, Fauci said.
He pointed out, however, that the immune response for those who had been infected and subsequently vaccinated, commonly called “hybrid immunity”, is higher than either infection or vaccination alone.
“The strength of the immune response that you get when you get an infection, followed by a vaccination regimen, is much higher than either infection or vaccination alone,” Fauci said. “So you know, I really can't tell yet whether there would be an extra bit of benefit from a boost.”
When asked about the risk of myocarditis in young males who would be getting a booster shot, Fauci acknowledged the FDA isn’t yet convinced of the need for a booster, and would need to look at more data to confirm that the benefits outweigh the risks.
Currently, just under 2 million people 18 to 50 years old have received a third dose.
“The FDA, understandably I think, is a bit skeptical about boosters for individuals who are less than 30 years old,” he said. “I think they're going to wait for more data on that.”
In September, the FDA’s vaccine advisory committee voted 16-to-2 against recommending a Pfizer booster for everyone ages 16 and up. Offit, a member of that committee, said that one concern was the uncertainty of the benefit in healthy people under the age of 30.
“The reason that we pushed back so hard was the otherwise healthy 16 to 29 year olds who will likely have little benefit and is at risk for myocarditis, in which case you could argue the risks outweigh the benefits,” Offit said.
“If they had said 30 instead of 16, I think this would have been much easier for both us and for the CDC.”
For young health care workers and other employees who may be eligible for a booster because of their occupation, Fauci said that, while it ultimately comes down to a person’s own risk aversion, he would personally opt for a booster if he were in their shoes.
“If I were in that group and I were a 25-year-old or 30-year-old resident doctor, which I was at one time, I would almost certainly get it [a booster].”