A study by Oregon researchers shows that people who are fully vaccinated against COVID-19 and have a breakthrough infection end up with what the authors call “superimmunity.”
They warn that vaccinees should not seek out COVID-19 infection, but the “hybrid immunity” offers some comfort to those who get one despite being vaccinated.
“The conclusion of the study is that vaccine provides you with fundamental immunity for what comes next,” said Fikadu Tafesse, a professor of molecular microbiology and immunology at Oregon Health & Science University School of Medicine in Portland, Oregon.
The study matched 26 vaccinated Oregon Health & Science University employees who had breakthrough infections with a similar group who had been vaccinated but not had COVID-19.
The people who were vaccinated and then got COVID-19 showed significant increases in antibody levels, Tafesse said.
“The increases were significant, going up to 1,000% and sometimes up to 2,000%, so it’s really high immunity,” he said. “It’s almost ‘super immunity’.”
Multiple other studies have shown that infection with COVID-19 followed by one dose of the vaccine is highly protective against reinfection.
“This is one of the first to show a breakthrough infection after vaccination that generates stronger immunity than a previous infection or vaccination alone,” said Dr. Monica Gandhi, an infectious disease expert at the University of California, San Francisco.
While potentially equally protective, the reverse order is not recommended. Getting COVID-19 before being vaccinated is dangerous because “we can’t predict who will get very sick with COVID,” Gandhi said.
As the highly contagious omicron variant continues to spread in the United States, the findings will be of interest to many, and “it is likely what the future will hold for most vaccinated individuals,” Gandi said.
Omicron appears to be able to infect even fully vaccinated people, although they appear to have mild or even asymptomatic cases of COVID-19 so far.
“What we’re saying is we know that life happens. If you happen to be exposed to the virus, you get an amazing immune response,” Tafesse said. “It reflects the immune response we get to the booster.”
The finding shows what a good job the immune system does, said Shane Crotty, a professor at the La Jolla Institute for Immunology in California.
Each time the immune system sees the vaccine or virus, it learns more and is better able to fight it and possibly other variants.
“This is what the immune system has evolved to do, to make guesses about something it’s been exposed to,” he said.
There is some information being circulated online claiming that getting vaccinated after recovering from COVID-19 is dangerous because it could overstimulate the immune system.
“That’s completely made up, it’s total bullshit,” Crotty said. “It has been tested in all vaccine trials. Getting vaccinated after exposure to COVID-19 is completely safe.”
Getting a booster is still safer than getting COVID-19, said Dr. Gregory Poland, director of the Mayo Clinic’s Vaccine Research Group, specifically for people at risk for serious illness, including people over the age of 70, people with diabetes and people with weakened immune systems.
“The best thing is to get three doses of an mRNA vaccine and never get infected. Complications, including long-term COVID and transmission to others, pose a risk even in that scenario,” Poland said.
He offered a hierarchy of security:
Best case scenario: fully vaccinated and boosted, no infection on exposure
Second best: fully vaccinated, boosted and asymptomatic or mild disease on exposure/infection
Next Best: Fully Vaccinated, Boosted, Moderate Disease and Associated Complications of Infection
Worse still: not fully vaccinated or boosted and risk of serious illness/death and its risks of infection
For those who have had COVID-19 and don’t think they should get vaccinated, Crotty suggested thinking differently.
“If you get at least one dose of vaccine, you have the best immunity of anyone,” he said. “You’ll have great immunity to omicron and every variant that’s been identified.”
This article originally appeared on USA TODAY: COVID Vaccination and Past Infection May Bring ‘Super Immunity’