Breakthrough infections could lead to an eventual end game of the COVID-19 pandemic: This is what scientists are saying after conducting tests on live SARS-CoV-2 virus exposed to blood samples collected from vaccinated individuals.

Study On COVID-19 Protection

In a study published in the Journal of the American Medical Association, researchers from the Oregon Health & Science University (OHSU) said that individuals who received two doses of the Pfizer vaccine developed a significant number of antibodies against the novel coronavirus after suffering a breakthrough case of COVID-19. The neutralizing antibodies they formed were as much as 1,000% times more effective than the ones they had developed after getting vaccinated.

For the study, the team collected blood samples from 52 people — university employees vaccinated with two doses of Pfizer’s biological preparation. From the 52, 26 contracted breakthrough cases of COVID-19. Ten of them were diagnosed with the delta variant, nine were non-delta and seven had unknown variants.

The researchers measured the immune response of the blood samples with mild breakthrough infection to the live SARS-CoV-2 virus and compared it to the control group (fully vaccinated without breakthrough infection). They discovered that those who had breakthrough cases developed more antibodies than those who did not contract the virus after vaccination. They also found that the neutralizing antibodies in the samples were “substantially better” at countering the virus.

Finding “Super Immunity”

After analyzing their data, the researchers indicated that fully vaccinated individuals who contract a breakthrough case could develop “super immunity” — a type of protection that provides a stronger immune response to subsequent exposers, even to new variants.

“You can’t get a better immune response than this,” senior author and assistant professor of molecular microbiology and immunology at OHSU Dr. Fikadu Tafesse said in a press release before noting that the vaccines are “very effective against severe disease.”

Whether this type of immunity could be the key to ending the pandemic remains unknown. But the authors are optimistic that this could be where most people are heading once they get vaccinated against the novel coronavirus.

“I think this speaks to an eventual end game. 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,” co-author and associate professor of medicine in the OHSU School of Medicine Dr. Marcel Curlin said.

Study Limitations

The team recognized that their study does have limitations. Among them is the absence of data related to the new variant of concern, the omicron variant. Tafesse acknowledged that they had not examined omicron, so they were uncertain if they would yield the same results with the new variant. However, the senior author maintained that it is possible for breakthrough cases from omicron to generate a “similarly strong immune response.”

Other shortcomings of the study were the small number of samples and the difference in the times when the samples were collected and the days when the participants were vaccinated. Further research would help establish the findings of the study. But for now, the team is urging everyone to get vaccinated for them to have “a foundation of protection” against COVID-19.

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