Brianna Vazquez undergoes coronavirus test in San Diego on January 1, 2021 (Ariana Drechsler / New York Times)
A virus that shows no signs of extinction, options that can avoid the body’s defenses and waves of infections two, maybe three times a year – this may be the future of COVID-19, some scientists fear.
The main problem is that the coronavirus has become more adept at re-infecting humans. Already infected with the first variant of omicron reported second infections with newer versions of the variant – BA.2 or BA2.12.1 in the United States or BA.4 and BA.5 in South Africa.
These people may continue to have a third or fourth infection, even within this year, researchers said in interviews. And some small parts may have symptoms that last for months or years, a condition known as prolonged COVID.
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“I think it’s likely to be a long-term model,” said Juliet Puliam, an epidemiologist at Stellenbosch University in South Africa.
“The virus will continue to grow,” she added. “And there will probably be a lot of people getting a lot, a lot of re-infections all their lives.
It is difficult to determine how often people become re-infected, in part because many infections are not currently reported. Pulliam and her colleagues have collected enough data in South Africa to say that the percentage is higher with omicron than in previous versions.
It shouldn’t have been. Earlier in the pandemic, experts believed that immunity from vaccination or a previous infection would prevent re-infections.
The omicron version shattered those hopes. Unlike previous variants, omicron and many of its descendants appear to have evolved to partially avoid immunity. This makes everyone – even those who have been vaccinated repeatedly – vulnerable to many infections.
“If we run it the way we run it now, then most people will get it at least a few times a year,” said Christian Andersen, a virologist at the Scripps Research Institute in San Diego. “I would be very surprised if things don’t turn out that way.”
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The new variants have not changed the fundamental usefulness of COVID vaccines. Most people who have received three or even just two doses will not get sick enough to need medical attention if the test is positive for coronavirus. And a booster dose, like a previous encounter with the virus, seems to reduce the likelihood of re-infection – but not much.
At the beginning of the pandemic, many experts based their expectations on the influenza coronavirus, the viral enemy they know best. They predicted that, as with the flu, there could be one large outbreak each year, most likely in the fall. The way to minimize its spread is to vaccinate people before they arrive.
Instead, the coronavirus behaves more like four of its close cousins, which circulate and cause colds throughout the year. While studying coronaviruses for the common cold, “we saw people with multiple infections in one year,” said Jeffrey Shaman, an epidemiologist at Columbia University in New York.
If re-infection proves to be the norm, the coronavirus “will not be just that winter time once a year,” he said, “and will not be a slight inconvenience in terms of morbidity and mortality it causes.”
Reinfections with earlier variants, including delta, occurred but were relatively rare. But in September, the rate of re-infections in South Africa appears to have accelerated and was significantly higher until November, when the omicron variant was identified, Pulliam said.
Recurrent infections in South Africa, as well as in the United States, may seem even more noticeable because so many of them have been immunized or infected at least once.
“Perception increases what actually happens biologically,” Pulliam said. “There are just more people who are eligible for re-infection.”
The omicron variant was quite different from the delta and delta of earlier versions of the virus, so some re-infections could be expected. But now it seems that omicron is developing new forms that penetrate the immune system with relatively few changes in its genetic code.
“It’s actually a bit of a surprise to me,” said Alex Seagal, a virologist at the African Institute of Health Research. “I thought we would need a brand new option to get away from this. But you don’t really seem to be doing it. “
Omicron infection elicits a weaker immune response, which appears to be rapidly declining compared to previous variants. Although newer versions of the variant are closely related, they differ sufficiently from an immune point of view, so that infection with one does not leave much protection against the other – and certainly not after three or four months.
Still, the good news is that most people who are re-infected with new versions of omicron will not get seriously ill. At least for now, the virus has not found a way to completely bypass the immune system.
“This is probably as good as it is so far,” Seagal said. “The great danger may come when the option is completely different.”
However, any infection can bring with it the possibility of prolonged COVID, a constellation of symptoms that can last for months or years. It is too early to know how often omicron infection leads to prolonged COVID, especially in vaccinated people.
To keep up with the evolving virus, other experts said, COVID vaccines need to be updated faster, even faster, than flu vaccines each year. Even an imperfect match with a new form of coronavirus will still boost immunity and offer some protection, they said.
“Every time we think we’ve been through this, every time we think we have the upper hand, the virus does the trick,” Andersen said. “The way to control it is not” Let’s all get infected several times a year and then hope for the best. “
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