Scientists say a Covid infection after vaccination triggers ‘super-immunity’

A new breed of ‘super immune’ Aussies are walking among us, as scientists claim there’s a new group who have a massive advantage.

Scientists have claimed that a so-called “super-immunity” to Covid-19 can be achieved by people who have been infected by the virus after receiving the vaccine for the disease.

In a new paper, Oregon Health and Science University (OHSU), experts say the same is also true for people who get infected before getting two jabs.

They said the two forms of immunity – breakthrough infections following vaccination or natural infection followed by vaccination – provide roughly equal levels of enhanced immune protection.

“It makes no difference whether you get infected and then vaccinated, or if you get vaccinated and then a breakthrough infection,” said co-senior author Fikadu Tafesse, PhD, assistant professor of molecular microbiology and immunology in the OHSU School of Medicine.

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

The research goes on to show that the immune response of fully-jabbed people following breakthrough infections is “extremely high” – describing it as “super immunity”.

The researchers found their antibodies were 10 times more potent than proteins made by participants who managed to dodge Covid completely.

The researchers found those who have been jabbed and then get Covid have ‘super-immunity’. Picture: Jeremy Piper/NCA NewsWire

The study is the first of its kind in the world – whereby academics took blood samples from more than 100 fully vaccinated volunteers and exposed them against three different strains of coronavirus.

It found that it doesn’t matter whether someone gets a breakthrough infection or gets vaccinated after a natural infection.

“In both cases, the immune response measured in blood serum revealed antibodies that were equally more abundant and more potent – at least 10 times more potent – than immunity generated by vaccination alone,” the authors wrote.

The study was done before the emergence of the highly transmissible Omicron variant, but researchers expect the immune responses they detected would be similar for the highly-transmissible strain.

“The likelihood of getting breakthrough infections is high because there is so much virus around us right now,” Dr Tafesse said. “But we position ourselves better by getting vaccinated. And if the virus comes, we’ll get a milder case and end up with this super immunity.”

The researchers said that the two forms of immunity provide roughly equal levels of enhanced immune protection. Picture: Brendan Radke

Researchers recruited a total of 104 people, all OHSU employees who were vaccinated by the Pfizer vaccine, and then carefully divided them into three groups: 42 who were vaccinated with no infection, 31 who were vaccinated after an infection, and 31 who had breakthrough infections following vaccination.

Controlling for age, sex and time from vaccination and infection, the researchers drew blood samples from each participant and exposed the samples to three variants of the live virus in a Biosafety Level 3 lab.

They found both of the groups with “hybrid immunity” generated greater levels of immunity compared with the group that was vaccinated with no infection.

A path toward endemic Covid

With the wildly contagious Omicron variant now circulating across the globe, the researchers say the new findings suggest each new breakthrough infection potentially brings the pandemic closer to the end.

“I would expect at this point many vaccinated people are going to wind up with breakthrough infections – and hence a form of hybrid immunity,” said senior co-author Bill Messer, M.D., Ph.D., assistant professor of molecular microbiology and immunology, and medicine.

He says that, over time, the virus will run into an ever-expanding pool of human immunity.

OHSU scientists say they haven’t tested multiple rounds of natural infection, although many people will likely find themselves in that category, given that millions around the world remain entirely unvaccinated.

With the spread of the highly contagious Omicron variant, many unvaccinated people who were previously infected are likely to confront the virus again.

The omicron variant is predicted by some to end the pandemic. Picture: Dr Jason A. Roberts, Head, Electron Microscopy and Structural Virology, Doherty Institute

For that group, previous research reveals a much more variable level of immune response than vaccination, Dr Messer said.

“I can guarantee that such immunity will be variable, with some people getting equivalent immunity to vaccination, but most will not,” he said. “And there is no way, short of laboratory testing, to know who gets what immunity.

“Vaccination makes it much more likely to be assured of a good immune response.”

Senior co-author Marcel Curlin, M.D., said immunity from natural infection alone is variable. “Some people produce a strong response and others do not,” he said. “But vaccination combined with immunity from infection almost always provides very strong responses.

“These results, together with our previous work, point to a time when SARS-CoV-2 may become a mostly mild endemic infection like a seasonal respiratory tract infection, instead of a worldwide pandemic.”