Earlier in the pandemic, infection was assumed to provide some degree of lasting protection, perhaps for a few months.
With the coronavirus mutating, this is no longer a foregone conclusion. Each individual infection carries a risk not only of developing acute illness but also the possibility of developing COVID for a long time.
“The risks of additives are really neither trivial nor insignificant. It’s really substantive,” said Dr. Ziad Al-Aly, a clinical epidemiologist at Washington University in St. Louis and head of research and development for the Veterans Affairs Health Care System in St. Louis.
According to a preprint study examining US veterans, of which Al-Ali is the lead author, infection two or more times “contributes to additional risks of all-cause mortality, hospitalization and adverse health outcomes” in various organ systems, and can also exacerbate risks. For diabetes, fatigue and mental health disorders.
“Re-infection definitely adds risk,” Al-Ali said. The study indicated that compared to those infected only once, individuals who contracted the virus for the second time were two and a half times more likely to develop heart or lung disease and blood clotting problems. Subsequent infections have also been associated with an increased risk of serious health problems, as well as death from COVID-19.
Al-Ali said it’s possible that repeated coronavirus infections will leave a person unwell, which is what happens to most people. “But you might be one of the unlucky ones and… have a really serious health problem because of the infection.”
“I think having some pre-existing immunity – whether it’s natural or from a vaccine – seems to reduce the risk of getting COVID for a long time, but it’s still there,” said Dr. Stephen Dicks, UCSF professor of medicine and lead researcher on the long-term effect. Long-term infection with the emerging coronavirus, “it’s not zero.”
A separate report noted that even adults who received a booster dose still had to consider the risk of contracting the Covid virus for a long time. A British report said that during the initial omicron wave, about 1 in 25 triple-vaccinated adults reported having had COVID for a prolonged period three to four months after the first infection.
However, some doctors say long-term coronavirus sufferers tend to be either not immune or missing out on their boosters.
The best way to prevent COVID for a long time is not to catch COVID-19. Many officials and experts cite non-pharmacological interventions such as masking as key tools, because vaccinations reduce risks but do not eliminate them completely.