Catching COVID-19 after vaccination can overload the immune system, making it better able to fight off new variants, according to a new study.
The small study included just 26 people with breakthrough infections, and all participants had received the Pfizer-BioNTech vaccine, so there are no data on other brands of vaccine, according to new research, released Thursday. (December 16) in the newspaper JAMA. But it does suggest that in general, those who catch COVID-19 after vaccination may have an advantage in fighting the disease. virus, even though they are exposed to a new variant of the coronavirus, study co-author Dr. Marcel Curlin, associate professor of medicine at the Oregon Health & Science University (OHSU) School of Medicine, told KATU News.
Of course, while this study highlights a potential silver lining for catching a breakthrough infection, getting COVID-19 after vaccination still carries risks. For example, breakthrough infections can lead to a long COVID, a syndrome in which people experience a variety of symptoms – from debilitating fatigue to cognitive dysfunction to gastrointestinal issues – for several months after their initial infection has cleared up. COVID-19, Reuters reported.
Related: Coronavirus variants: facts about omicron, delta and other COVID-19 mutants
For the study, Curlin and his colleagues collected some blood samples from 26 OHSU health workers, all of whom contracted COVID-19 after being fully immunized, meaning they had received two doses of the Pfizer-BioNTech vaccine. None of the participants had had COVID-19 prior to their breakthrough infections, and 24 of the 26 breakthrough infections caused only “mild symptoms,” the team reported. The researchers analyzed viral samples from 19 of these breakthroughs and found that 10 were caused by the delta variant and nine were non-delta infections.
The team compared the blood of these breakthrough cases to that of 26 OHSU health workers who were also fully vaccinated with Pfizer-BioNTech injections but did not catch a breakthrough infection.
The team isolated a clear, yellowish liquid called serum from the blood samples and placed the serum in lab dishes with cultured human cells and SARS-CoV-2, the virus that causes COVID-19 . Then, using an assessment called the “Focus Reduction Neutralization Test”, they determined how effectively the antibody in the neutralized serum on coronavirus. When antibodies neutralize a virus, they attach themselves to the virus so that the insect can no longer infect cells.
The team conducted experiments with the original strain of SARS-CoV-2 and the alpha, beta, gamma and delta variants of concern, according to the JAMA report. (They did not conduct any experiments with the recently identified omicron variant.) These experiments found that the serum of those with breakthrough infections neutralized different versions of the virus more effectively than that of the control group.
“So if I take a person who just got vaccinated on their own, and someone who’s had a vaccine plus a breakthrough, and I take their serum and now compare it to the alpha variant, or the delta variant, beta … In any case, the vaccinated infected person has a much better ability to cope with these other variants, regardless of which variant he / she has been infected with, ”Curlin told KATU News.
In general, compared to controls, the blood of people with breakthrough infections contained more antibodies that bind to the receptor binding domain (RBD) of the virus spike protein, which binds directly to the surface. cellular. These RBD-specific antibodies are considered to be the most critical to neutralize the coronavirus, Previously reported live science.
Based on neutralization tests, the revolutionary group’s serum was about 950% more potent against the original SARS-CoV-2 virus, compared to controls, the team reported. Antibody responses against the variants of concern were similarly enhanced; for example, the serum from the breakthrough group was about 1021% more potent against delta than that from the control group.
Serum from delta breakthrough infections showed higher potency against the variant than serum from controls or non-delta breakthroughs. This suggests that the development of boosters corresponding to different variants could help “broaden” the immune response elicited by the vaccine, the team noted.
Yet vaccination, on its own, is protective, even though the combination of vaccination and a breakthrough infection triggers a more potent immune response, Curlin told KATU News. “What we are looking at is the exceptional combination of vaccination and infection,” he said. “So if you are infected on your own without a vaccine, the immune response is quite variable from person to person and, on average, a little weaker than if you are vaccinated.”
Learn more about the JAMA study in KATU News.
Originally posted on Live Science.