Questions remain about whether or not the effectiveness of the COVID-19 vaccine is waning, and whether or not drops in antibodies may be leading to more breakthrough cases of COVID-19.
Much of the talk about waning immunity began with data out of Israel, one of the world’s most vaccinated countries. The country has often been seen as a template for COVID-19 vaccine distribution. And, recently, Israel “has been offering a coronavirus booster to people over 60 who were already vaccinated more than five months ago,” per The Associated Press.
The data from Israel found that “the Pfizer-BioNTech vaccine’s protection against severe disease has fallen significantly for elderly people who got their second shot in January or February,” per The New York Times.
And experts told The New York Times that Israel’s data showed “continued erosion of the efficacy of the Pfizer vaccine against mild or asymptomatic COVID-19 infections in general and against severe disease among the elderly who were vaccinated early in the year.”
This led the United States to change its own COVID-19 vaccine policy, calling on all fully vaccinated Americans to get a third shot — a booster shot — to ward off the delta variant and prepare for any variants.
But, according to The New York Times, there are some scientists who are questioning whether or not immunity is really waning among vaccinated people. Scientists agree immunity will drop off over time, but it may not be as dramatic as we think.
“There’s a big difference between needing another shot every six months versus every five years,” Dr. David Dowdy, an epidemiologist at Johns Hopkins University, told The New York Times. “So far, looking at the data we have, I’m not seeing much evidence that we’ve reached that point yet.”
To put it simply, there isn’t heavy data out there about the need for COVID-19 booster shots. The call for booster shots has been spearheaded by data about the waning efficacy of the vaccines.
But even that data — the aforementioned data from Israel — has some plot holes, too. For example, the Israel data found that people vaccinated in the winter were catching the virus more often than those vaccinated in the spring, scientists told The New York Times.
However, the winter group was educated and affluent. So after getting the vaccines, they took more risks — like travel or engaging with others. So they were exposed to the delta variant.
Deepta Bhattacharya, a bioimmunologist at the University of Arizona, recently told NPR that some of the reports on waning immunity might be a little dramatic.
“If you get a big dose of delta, as the variant often gives, the virus can slip past the initial wall of antibodies,” he told NPR. “So I think we may be seeing some signs of that. But the (level of breakthrough infections) is probably not as dramatic as I think it’s being made out to be.”
Bhattacharya explained that COVID-19 antibodies become stronger over time. So now — about six months into your vaccination — your antibodies are well equipped to stop COVID-19, and it might even take fewer antibodies to stop the virus.
“The quality of the antibody improves over time. It takes far fewer of those new antibodies to protect you,” Bhattacharya told NPR. “So I think that worrying about antibody decline is not something that’s productive,” he adds.
Ali Ellebedy, an immunologist at Washington University in St. Louis, told NPR that the vaccine has been preparing for months to fight off the coronavirus.
“If you were vaccinated six months ago, your immune system has been training for six months — you are better ready to fight a COVID-19 infection,” said Ellebedy.