COVID infection when fully vaccinated gives you ‘super immunity,’ study suggests
COVID-19 infection after vaccination has always been possible, and may be more likely now that early data suggests the omicron variant can evade vaccines’ defenses.
But a new small study suggests that if you contract a breakthrough case — infections that occur two or more weeks after complete vaccination — you may be gifted with “super immunity.”
Laboratory research on blood samples from 52 health care workers, half of whom were fully vaccinated and contracted COVID-19, found breakthrough infections generated more antibodies that were “as much as 1,000% more effective” than those produced two weeks after a second dose of the Pfizer vaccine, according to an Oregon Health & Science University news release. Study participants were all OHSU employees.
Researchers did not test how antibodies from breakthrough cases fared against the omicron variant, which appears to be more contagious than previous variants.
But the findings suggest “breakthrough infections from the omicron variant will generate a similarly strong immune response among vaccinated people,” senior study author Fikadu Tafesse, an assistant professor of molecular microbiology and immunology in the OHSU School of Medicine, said in the release. The study was published Thursday, Dec. 16 in JAMA.
“You can’t get a better immune response than this,” Tafesse said. “These vaccines are very effective against severe disease. Our study suggests that individuals who are vaccinated and then exposed to a breakthrough infection have super immunity.”
Researchers measured immune responses by exposing live coronavirus to 26 blood samples from people who developed a breakthrough case; 10 comprised the delta variant and all others were of other or unknown variants. The team then exposed live coronavirus to another 26 blood samples from fully vaccinated people without a breakthrough case for comparison.
Omicron variant causing more breakthrough infections
The omicron variant is giving people 2020 deja vu.
It has canceled Broadway performances in New York City, reissued statewide face mask mandates and returned college students to online classes.
Laboratory experiments on blood samples from people who received a Pfizer booster a month ago found antibody levels increased 25-fold against omicron, similar to levels seen after two doses against the original version of the coronavirus.
Blood from people who only received two doses of the vaccine, however, experienced a 25-fold reduction in antibody levels against the omicron variant, on average, suggesting two shots may not protect against omicron infection.
Yet, two Pfizer doses may still protect against severe COVID-19, experts say, including hospitalization and death.
Similar results were found during laboratory research of the Moderna vaccine, NPR reported, and several studies from around the world show the initial doses of the vaccines lose some power against omicron.
Researchers of the new study speculate the pandemic will slow down over time as people, including the unvaccinated, fully vaccinated and boosted, contract omicron or other variants and build stronger protection with each exposure.
“I think this speaks to an eventual end game,” study co-author Dr. Marcel Curlin, an associate professor of medicine at OHSU, said in the release. “It doesn’t mean we’re at the end of the pandemic, but it points to where we’re likely to land: Once you’re vaccinated and then exposed to the virus, you’re probably going to be reasonably well-protected from future variants.”
This story was originally published December 17, 2021 at 2:54 PM with the headline "COVID infection when fully vaccinated gives you ‘super immunity,’ study suggests."
