“The solution isn’t just throwing vaccines at everybody. It’s actually having a meaningful understanding of what are the goals of the vaccine program and what can we expect the vaccines to do,” Isaac Bogoch, an infectious disease physician and scientist at the University of Toronto, told HuffPost.
Experts expect COVID boosters will be recommended for some, but not all
Bogoch said in order to determine if, when and how boosters will be needed, it’s crucial to first look at the goals.
The current shots have waning protection against infection and onward transmission, Bogoch explained, but they continue to be safe and very effective at preventing severe outcomes like hospitalizations and death.
Health officials will need to decide if they want boosters to prevent hospitalization and death (which the initial shots still do in most people) or to prevent symptomatic COVID (a harder feat), according to Arjun Venkatesh, a Yale Medicine emergency medicine doctor and associate professor at Yale School of Medicine.
The effectiveness of vaccines varies between people. Immunocompromised individuals and older people’s antibody levels wane earlier, which makes these people strong candidates for booster doses, Venkatesh said.
“The reason we want to boost older adults first is because in many ways, the vaccine — their first two doses — didn’t work as well as it worked in younger people,” Venkatesh said. That second booster has helped at-risk groups be “as vaccinated” as healthier individuals who got only two doses.
It’s reasonable to expect that the next round of boosters will be recommended for vulnerable individuals before the next wave of the pandemic this fall, Bogoch said.
Venkatesh also believes we will see booster campaigns targeting at-risk populations more than blanket booster recommendations. It’s not uncommon for booster campaigns to roll out for select groups — we already do this for shingles, pneumonia and flu shots.
When will the general population get another booster?
Trials have shown that a fourth dose of the currently available vaccines doesn’t provide much more protection against mild or asymptomatic infections than a third dose in healthy people under 50, according to Supriya Narasimhan, the division chief of infectious diseases and hospital epidemiologist and medical director of infection prevention at Santa Clara Valley Medical Center.
“The increase in vaccine efficacy was small and short-lived, therefore the benefit of an additional dose is not thought to be great,” Narasimhan said, noting that the benefits of a fourth dose were much more pronounced in people over 60.
As of now, it’s unclear if and when the general population should get an additional booster dose.
“That’s going to be based, largely, on when we start seeing young, healthy people being at risk for hospitalization or death — because that’s the outcome we’re trying to prevent — or when we see young, healthy people have waning levels of antibodies” that put them at risk, Venkatesh said. That would suggest it’s time for everybody to get another shot.
Bogoch suspects booster campaigns will vary from place to place. The United Kingdom recently suggested its fall booster campaign would be limited to older and more vulnerable people. Quebec, on the other hand, already made a booster dose available for anyone over the age of 18 who wants it. Bogoch wouldn’t be surprised if health authorities elsewhere eventually say that anyone who wants a dose can get it.
What about updated versions of the COVID vaccine that target new variants?
Last week, Moderna announced its omicron-specific booster was well tolerated and demonstrated a more robust antibody response against omicron variants than the original COVID shot. The company hopes to submit preliminary data soon. If authorized, the shots will be available in late summer, with booster options in the fall.
Pfizer is also working on a fall booster, though little data has been released on that. The FDA recently recommenced authorization for the Novavax vaccine’s primary series, but the shot is still being studied as a booster.
It’s difficult to predict when the new versions of the COVID vaccines will be available, Bogoch said. Even though they’ve been developed and are being tested, that doesn’t mean they will be recommended for everyone. Vaccine scientists and health officials will first need to figure out if the new shots help people regain protection against infection and onward transmission — and, if so, how well, Bogoch said.
“It’s completely expected that something like that would still protect against severe protection, hospitalization and death — but can we regain protection against infection and onward transmission and can we do so in a durable manner that doesn’t wane over a couple of months?” Bogoch asked. These questions have not yet been answered.
Venkatesh suspects that, like the flu, we will eventually have annual vaccines for COVID. At some point, we may pivot to different types of vaccines — like intranasal vaccines that can help fight transmission and pan-coronavirus vaccines that can target various types of coronaviruses at once. But we won’t see these in 2022, Bogoch noted.
For now, experts want to tread carefully when it comes to boosters and prioritize them for the people who need them most while tracking how the current shots hold up in the rest of the population.
“It is important that we are timely and cautious in deploying additional boosters for the general population because the increase in protection is likely to be small and short-lived, especially in those who have hybrid immunity due to infection and vaccination,” Narasimhan said.
Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.