Among the many still-unanswered questions medical experts have about the coronavirus is whether it is possible to develop “super immunity” to the virus.

To find out if full immunity from the virus is possible, researchers at the Oregon Health & Science University (OHSU) explored two paths. The first was to see if breakthrough infections after vaccination boost immunity. And the other: Whether getting vaccinated after an infection can also offer robust immunity.

Their findings are good news. It turns out both offer almost equal levels of enhanced protection.

“In either case, you will get a really, really robust immune response — amazingly high.”

“It makes no difference whether you get infected-and-then-vaccinated, or if you get vaccinated-and-then-a-breakthrough infection,” one of the study’s co-senior authors, Fikadu Tafesse, an assistant professor of molecular microbiology in the OHSU School of Medicine, said in a statement. “In either case, you will get a really, really robust immune response — amazingly high.”

Over 100 Oregon Health & Science University employees who had received the Pfizer vaccine were divided into three groups for the study: 42 were vaccinated with no breakthrough infection, 31 were vaccinated after an infection, and 31 had breakthrough infections following vaccination. After controlling for age, sex and time from vaccination and infection, the researchers took blood samples from each participant. Then they exposed the samples to three variants of the live SARS -CoV-2 virus in a Biosafety Level 3 lab on campus. Both groups with “hybrid immunity” ended up having greater levels of immunity when compared to the group that was vaccinated with no follow up infection.

The study was conducted before Omicron’s spread, but the researchers suspect that immunity will hold up with the new variant too.

Immunity from natural infection though is variable. While some folks produced a strong response, others did not. That’s why vaccination and booster is still the best action to take to avoid serious infection. “Vaccination makes it much more likely to be assured of a good immune response,” said the study’s other senior co-author, Bill Messer, an assistant professor of molecular microbiology and immunology and medicine in the OSHU School of Medicine. “I would expect at this point many vaccinated people are going to wind up with breakthrough infections — and hence a form of hybrid immunity.”

The findings, however are definitely promising for the future. With the Omicron variant traveling around the world, the research suggests that numerous breakthrough infections have the potential to bring the pandemic closer to the finish line.

The study is published in Science Immunology.