In recent weeks, the spread of the delta variant and with news of breakthrough COVID-19 cases — infections that occur in people who have been fully vaccinated — have some people who received the vaccines on edge: is their protection against the virus waning? Are they due for another dose to help bolster immunity?
In the last week, the New York Times reported that federal health officials — who initially said evidence didn’t yet support another shot — are beginning to believe another COVID-19 vaccine dose may be needed for people age 65 and older and for those who are immunosuppressed.
That doesn’t mean people in those categories can show up to the local pharmacy and get another shot just now. Here’s what you need to know about potential COVID-19 “boosters.”
The case for boosters
Earlier this month, Pfizer, one of the companies that manufactured a COVID-19 vaccine, told the federal government it would seek Food and Drug Administration approval for an additional dose of its vaccine.
Citing the efficacy of the three COVID-19 vaccines approved under emergency use authorization — those by Pfizer, Moderna and Johnson & Johnson — the FDA and the Centers for Disease Control said there wasn’t evidence to support the need for additional doses at the time.
The administration is apparently changing course somewhat, at least partly based on new evidence that the immunity generated by the Pfizer vaccine begins to wane within months of vaccination, the New York Times reported.
This week, Pfizer reported its research showed the vaccine’s efficacy rate against symptomatic COVID-19 was about 96 percent for two months after the second dose. Four to six months after the second dose, it fell to 83.7 percent. The vaccine’s efficacy against severe disease remained at 97 percent. The results have not yet been peer-reviewed.
The study concluded before the Delta variant was highly prevalent, and many researchers do not see the findings as a case for another dose for the general public, reasoning the vaccines remain very effective. Antibodies, as measured in these studies, are just one part of the immune system and are not the body’s only defense.
Who would be eligible
As of this week, MDH has confirmed 3,886 breakthrough cases. There have been 417 breakthrough hospitalizations, with a median age of 73, and 53 breakthrough deaths, with a median age of 78. Of people who have been vaccinated in Minnesota, 99.9 percent have not contracted COVID-19, the Minnesota Department of Health said this week, and the driver of rising cases and hospitalizations continues to be the unvaccinated.
If an additional dose were to be authorized, at least as of now, federal officials are suggesting it would likely only be for those who are currently most at risk of hospitalization and death from COVID-19, even after vaccination: older people and sick people.
“Beyond age 65 and older, we generally don’t have the same strength of immunity as we did when we were younger,” said Louis Mansky, the director of the Institute for Molecular Virology at the University of Minnesota.
As for the immunocompromised, that could mean organ transplant patients or others with health conditions that cause a weakened immune system, Mansky said.
Mansky said the fact that officials aren’t discussing another dose for the general population should give vaccinated people confidence in the vaccine.
“I think that we should all have strong faith that for the vast majority of us who have sought out vaccination and are considered to be fully vaccinated, that we should feel pretty confident that we’re in a much safer place as a result,” Mansky said.
That also goes for Johnson & Johnson recipients, Mansky said, which some people perceive to be inferior.
“The differences [between the vaccines] are small enough that I don’t think it’s fair to say the Johnson & Johnson vaccine is not as protective as the other vaccines,” he said.
If a follow-up vaccination is approved, it could happen relatively quickly, Mansky said, given that the technology would be the same as the previous mRNA vaccines. As for whether Johnson & Johnson recipients could receive a follow-up mRNA vaccine, that would be the subject of trials before it is approved, too, Mansky said.
In press call this week, MDH Infectious Disease Director Kris Ehresmann said Minnesota would not authorize follow-up COVID-19 vaccines until they are approved by the FDA.
“There is emerging evidence that all of the available COVID-19 vaccines provide protection against COVID-19 variants, including preventing severe disease from the Delta variant,” she said in an email. “At this time, the single best thing Minnesotans can do to protect themselves and their communities is receive one of the highly-effective vaccines currently available.”