A team of researchers from the University of Gothenburg has just taken a new step to understand how the immune system develops resistance to COVID19.
For 6 months, researchers from the University’s Sahlgrenska Academy investigated 156 employees from 5 primary healthcare facilities who were recruited between April & May 2020. None of these employees had been vaccinated against COVID19 and most of them had to work daily with infected patients on daily basis during the height of pandemic.
They identified IgA (immunoglobulin A) in respiratory tracts of several of personnel who didn’t have COVID19, which could mean they had an antidote in their immune system the whole time.
These antibodies are found naturally in mucous membrane secretions within the airways & gastrointestinal tract, wherever they shield the body by binding to viruses & other invading organisms.
An antidote in immune system
COVID19, an infectious disease caused by the SARSCoV2 virus, has claimed the lives of over 6 million people since the pandemic began in early 2020. In fact, some researchers say the actual number of lives lost to COVID19 as of December 31, 2021 was 18.2 million, which is more than 3 times the official death toll.
The disease seems to affect some people more severely than others, with some showing very mild symptoms and others being hospitalized and requiring aid-in-breathing. The current study aimed to uncover the health factors that appeared to offer protection against COVID19 in unvaccinated people.
“We all have IgA,” said Christine Wennerås, professor of clinical bacteriology at the University of Gothenburg’s, Sahlgrenska Academy and senior physician at Sahlgrenska University Hospital, who is part of the research team.
“It is found on mucous membranes, and COVID19 is an infection that spreads through these membranes. We thought it was important to investigate what happened when perfectly healthy people encountered the coronavirus , before vaccines became available.
“Of the participants in our study, none of those who contracted COVID19 required hospitalization,” she continued. “A lot of other research has concerned the most seriously ill patients who have been hospitalized & need intensive care.
According to study results published in the European Journal of Immunology, a third of healthcare workers have developed antibodies against COVID19 and fell into 2 distinct groups based on antibody patterns & COVID19 incidence. .
A group that only possessed IgA antibodies never succumbed to COVID19. The participants in the other group had IgG antibodies and T cells and got sickness.
Participants who did not test positive or were unwell had IgA antibodies. Other characteristics that appeared to provide-protection against infection were being female and having a respiratory-allergy.
However, the data doesn’t support the idea that those who don’t have COVID-19 antibodies have protective T cells, which are part of the immune system that targets specific foreign particles.
It should be noted that most COVID19 vaccines are highly effective against serious illness, hospitalization & death. As Omicron’s subvariant BA.2 replaces its sister version BA.1 as the dominant form of COVID19 in many countries, researchers have found that 2 doses of the COVID vaccine still appear to reduce the risk of infection caused by the new subvariant.