In 2021, it seemed that coronavirus reinfections were rare. Yes, they did happen, but the vast majority of people who had already had Covid probably wouldn’t get the virus again any time soon.
But recent data suggests reinfections are becoming more common, especially as new variants emerge. The rise in reinfections is likely influenced by two factors: one, that newer variants can evade the antibody response and reinfect, and two, that we are now more rigorously documenting reinfections and getting a more accurate picture of their frequency .
Coronaviruses are known to infect people over and over again. In fact, the common cold coronaviruses circulating today (and frequently reinfecting people) are widely believed to have originated from previous coronavirus epidemics.
Many infectious disease clinicians suspect that, as with those strains, we may be susceptible to reinfections, but that symptoms will get milder over time.
“As we get more immunity, as our T cells diversify and expand, hopefully our second reinfection won’t feel as bad as the first infection,” he said. Monica Gandhiinfectious disease specialist at the University of California, San Francisco.
This is how soon reinfections with Covid can happen now
We now know that antibodies, which work to prevent infection in the first place, start to dip a few months after vaccination or infection. Also, as the coronavirus mutated, it became a little less recognizable to the immune system.
Because of this, the variants can bypass the immune system’s first line of defense and reinfect us, according to julie parsonnettepidemiologist and professor of infectious diseases at Stanford University School of Medicine.
“With Omicron, we are seeing a lot of cases in people previously infected, even when they had also been vaccinated,” Parsonnet said.
“With Omicron, we are seeing many cases in people previously infected, even when they had also been vaccinated.”
– Julie Parsonnet, epidemiologist and professor of infectious diseases
Pablo Peñaloza-MacMaster, assistant professor of microbiology-immunology at Northwestern University Feinberg School of Medicine, said people who recently recovered from an infection or received a booster may be susceptible to reinfection in about six months.
Parsonnet noted that he has heard of at least one patient who was fully vaccinated and double-boosted who became infected with omicron six weeks after his previous infection.
A recent study from Denmark found that although very Rare, reinfections with omicron subvariants can occur in as little as 20 days. Of the 1.8 million infections registered between November 2021 and February 2022, 1,739 reinfections were detected in 60 days.
This does not mean that a couple of months after recovering, there is a good chance that you will get Covid again. In fact, a preprint study recently found that infections in people who had already had Covid were 90% less common than in people who had never been infected. Getting infected in addition to the vaccine actually raises your antibody levels, and that should keep most people well protected from infection for at least four months, Gandhi said.
Identifying who may be more likely to be re-infected is not an exact science: some people will be better protected and have less risk of reinfections depending on factors such as their age, genetics and underlying health. The reinfection rate also depends on the variant, the type of mutations the virus has acquired, and the viral load someone is exposed to, according to Penaloza-MacMaster.
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Reinfection tends to be less severe.
Most of the evidence suggests that reinfections of COVID, in general, tend to be less severe than the initial infection. in danish studyalmost all people who had been reinfected with BA.2 after previously having BA.1 experienced mild symptoms for a few days and significantly lower viral loads the second time, even those who were not vaccinated.
Although our immune system weakens over time, the components that keep us safe from diseases and serious results remain solid and long-lasting (even when Dealing with new variants).
“Reinfections, especially in vaccinated people, are usually milder relative to the primary infection, because an arsenal of memory T-cells and B-cells already exists.” Penaloza-MacMaster said.
Investigate suggests that reinfections and boosters enhance the T-cell response. “Unsurprisingly, a reinfection fundamentally protects you even more” from serious outcomes, Gandhi said. Of course, boosters are the safest: you don’t want to re-infect yourself on purpose.
According to Peñaloza-MacMaster, the severity of an individual’s reinfection is also influenced by the variant they contract along with the dose of virus they are exposed to and whether they have underlying health conditions that put them at risk. But often it can be unpredictable.
How will reinfections affect prolonged COVID?
One of the key questions epidemiologists will track is how reinfections contribute to prolonged covid.
We know that Covid affects many organs, including the brain, lungs, and heart. Inflammation, which helps remove infected cells from the body, is a normal part of the body’s response to infection. When the body eliminates virus-infected cells, it also destroys our own healthy cells.
“MERemoving a virus involves a substantial amount of ‘collateral damage,’ which is one of the main reasons why long-term inflammation, which occurs during prolonged infections, is harmful,” Peñaloza-MacMaster said.
yes yhIt is not clear how reinfections contribute to prolonged covid and the potential damage to our organs. Investigate found that vaccination reduced the risk of prolonged covid in people who had advanced infection, Gandhi said. And while the vast majority of people who contract SARS-CoV-2 recover well with no long-term consequences, it remains to be seen whether this will continue to be the case after multiple infections.
“We don’t know the answer to this question, especially since as variants change and our immune systems react differently to them, their impacts on the body change,” Parsonnet said.
Experts are still learning about Covid-19. The information in this story is what was known or available at the time of publication, but guidance could change as scientists discover more about the virus. To keep up to date with health advice and cases in your area, visit gov.uk/coronavirus Y nhs.uk.