A few months ago, we thought that the recovery from COVID-19 meant that the chances of contracting the virus again so soon were low. The thought that we were protected for at least six months after the initial infection.
But now, as the hypertransmissible BA.5 variant moves across the country, more and more reinfections are being detected in people who have had COVID once, if not twice, before.
“Reinfections are due to a variety of reasons, including more relaxed safety precautions such as masking and social distancing, as well as declining antibody levels and additional viral mutations, which can lead to the escape of subvariants of ‘omicron,” Pablo Penaloza-MacMasteran, assistant professor of microbiology-immunology at Northwestern University Feinberg School of Medicine and an advisor to the Illinois Department of Public Health, told HuffPost.
In addition to SARS-CoV-2, there are four other coronaviruses that circulate and cause the common cold. These viruses are known to re-infect people after about 12 months on average, although there was hope that we would eventually achieve herd immunity to COVID, SARS-CoV-2 appears to behave like other coronaviruses to which we are exposed. year after year.
“Extrapolating from data with other coronaviruses, reinfections with SARS-CoV-2 variants are expected,” said Penaloza-MacMaster, who noted that BA.5 also has several mutations in the spike protein that facilitate the entry and accession of the coronavirus. in our cells. These mutations help to appear somewhat invisible to the antibodies our bodies produced during previous infections and vaccinations.
“This creates higher risks for people who are less protected against any infection,” said Albert ShawYale Medicine, MD, an infectious disease professor and professor of medicine at the Yale School of Medicine.
It is difficult to determine how quickly people are susceptible to reinfection, Shaw said. This timing largely depends on when you were last vaccinated or boosted, the state of your immune system, your age, and the presence of underlying health conditions.
The variant you were last infected with and when also affects your risk of reinfection. A preprint study from Qatar recently found that the effectiveness of a pre-omicron infection (such as delta or alpha) against a BA.5 infection was 28%, while the effectiveness of an omicron infection against a BA.5 infection was closer to 80%.
That’s likely to do with how many vaccines people had at the time and when they got infected, according to infectious disease epidemiologist Julie Parsonnetan of Stanford Medicine.
“If you were infected with delta, you were infected a relatively long time ago, and if you were infected with omicron, you were infected relatively recently, and that may mean that your immunity may be a little bit better just because it hasn’t worn off . time,” Parsonnet said.
Shaw said most people are probably still well protected for a few months, but beyond six months, the immunity that prevents symptomatic infections is likely to wane substantially. Some people have been reinfected in as little as four weeks,
According to Parsonnet, no matter how many times someone has been infected, there’s no way to be sure they’re 100 percent safe from getting COVID again. “I don’t think there’s anyone who can say, ‘I’m immune; I’m just not going to make it,” Parsonnet said.
Although we can’t prevent reinfections (yet), the vast majority of them will be less severe, as the body has memory immune responses that will likely remain intact for years. Penaloza-MacMaster said that while symptoms depend on the person, they can include headache, shortness of breath, cough, fatigue, fever, among others, or no symptoms at all. Symptoms also depend on the variant and how much virus a person is exposed to, he added.
At the same time, reinfections, even if they are less serious, can lead to new health problems. A preprint study from the University of Washington School of Medicine recently found that repeated COVID infections increase the risk of persistent health problems, such as lung and heart problems and digestive or kidney disorders, after infection. “The potential for some unpredictable consequences for these organ systems probably also increases with subsequent reinfections,” Shaw said.
Vaccines and boosters still do a good job of protecting us from serious outcomes, even with the new variants. Vaccination triggers a more robust immune response against the severe outcomes of COVID-19, which is why it’s so crucial to stay current on booster shots.
“It’s clear that vaccines and previous infections still protect against severe disease and severe disease, so that’s the bright side,” Parsonnet said.
Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but the guidance may change as scientists learn more about the virus. Check with the Centers for Disease Control and Prevention for the most up-to-date recommendations.