The Oregon Health & Science University study, which was published in the Journal of the American Medical Association, has discovered that antibodies in breakthrough case blood samples were at most 1,000% more effective than the antibodies found in non-infected blood samples taken two weeks after a Pfizer vaccination. The study collected blood samples from 52 university employees who had the Pfizer vaccine, and of the 26 of them who had mild breakthrough infections, 10 had the Delta variant, nine were described as non-Delta, and 7 had unknown variants.
A breakthrough infection “generates a robust immune response against the delta variant,” according to the summary of findings, and researchers believe that responses will be similar to other variants like Omicron.
“I think this speaks to an eventual end game,” co-author and associate professor of medicine Dr. Marcel Curlin said, per NBC 5. “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.”
The study also compared the immune response to a live virus from people with breakthrough cases to that of the control group, finding that “breakthrough cases generated more antibodies at baseline,” per NBC, with those antibodies being “substantially better” at neutralizing the live virus.
“The key is to get vaccinated,” Curlin said. “You’ve got to have a foundation of protection.”
The Omicron variant was not specifically identified in the study, but Fikadu Tafesse, a senior author and assistant professor of molecular microbiology and immunology, said those behind the study would “anticipate that breakthrough infections from the Omicron variant will generate a similarly strong immune response among vaccinated people.”