A virus that shows no signs of disappearing, variants that specialize in bolstering the body’s defenses and dodging waves of infection twice, perhaps three times a year – this could be the future of COVID-19, some scientists now afraid.
The central problem is that the coronavirus has become more efficient at re-infecting people. Already, those infected with the first Omicron version are reporting a second infection with the newer versions of the version – BA.2 or BA2.12.1 in the United States, or BA.4 and BA.5 in South Africa. .
The researchers interviewed said that those people may also have a third or fourth infection within this year. And a small fraction may have symptoms that persist for months or even years, a condition known as protracted COVID.
“I feel like this is going to be a long-term pattern,” said Juliet Pulliam, an epidemiologist at Stellenbosch University in South Africa.
“The virus will continue to evolve,” she said. “And probably a lot of people are going to have many, many re-infections in their entire lives.”
It is difficult to measure how often people are reinfected, partly because many infections are no longer being reported. Pulliam and his colleagues have gathered enough data in South Africa to say that the rate is higher with Omicron than with previous variants.
“Probably many people are going to have many, many re-infections in their entire lives”
— Juliet Pulliam, epidemiologist
This should not have happened. Earlier in the pandemic, experts thought that immunity from vaccination or previous infection would prevent re-infection.
The Omicron version dashed those hopes. Unlike previous forms, Omicron and many of its descendants have evolved to have partially dodge immunity. This leaves everyone – even those who have been vaccinated multiple times – vulnerable to multiple infections.
“If we manage it the way that we manage it now, most people will get infected with it at least twice a year,” said Kristian Andersen, a virologist at the Scripps Research Institute in San Diego. “I’d be very surprised if that’s not how it’s going to play out.”
The new variants have not changed the fundamental usefulness of COVID vaccines. Most people who have received three or just two doses will not be so ill that they need medical care if they test positive for the coronavirus. And the booster dose, as in the previous bout with the virus, reduces the chance of re-infection – but not by much.
At the start of the pandemic, many experts based their expectations of the coronavirus on influenza, the viral enemy most familiar to them. He predicted that, as with the flu, there could be a major outbreak each year, most likely in the fall. The way to reduce its spread would be to vaccinate people before it arrives.
Instead, the coronavirus is behaving like its four closely related cousins, which cause colds throughout the year. “We looked at people with multiple infections within a year,” said Jeffrey Shaman, an epidemiologist at Columbia University in New York who studies common-cold coronaviruses.
If reinfection becomes the norm, the coronavirus “is not going to be just once a year this winter,” he said, “and it’s not going to be a mild nuisance in terms of the amount of morbidity and mortality it causes. is.”
Re-transitions occurred with earlier variants, including the Delta, but were relatively few. But in September, the pace of re-infection in South Africa seemed to be accelerating and was significantly higher until November, when the Omicron variant was identified, Pulliam said.
The number of re-infections reported in South Africa, as in the United States, may seem like a big change, as so many people have been immunized or infected at least once by now.
“This notion extends to what is actually going on biologically,” Pulliam said. “It’s just that there are more people who are eligible for re-infection.”
The Omicron version was so different from Delta, and Delta from earlier versions of the virus, that some re-infection was to be expected. But now, Omicron is developing new forms that penetrate immune defenses with relatively few changes to its genetic code.
“It’s actually a bit of a surprise to me,” said Alex Sigal, a virologist at the Africa Health Research Institute. “I thought we’d need a kind of new version to survive this. But really, it sounds like you’re not.”
An infection with Omicron produces a weakened immune response, which tends to subside more quickly than with previous forms of infection. Although the newer versions of the variant are closely related, they differ enough from the point of view of immunity that infection with one does not leave much protection against the others – and certainly not after three or four months.
Still, the good news is that most people who are reinfected with newer versions of Omicron will not become seriously ill. At least for the time being, the virus hasn’t hit the immune system in a way that can completely overcome it.
“It’s probably as good as it gets for now,” Siegel said. “The bigger danger may come when the version will be completely different.”
Still, each infection can bring with it the possibility of a prolonged COVID, constellation of symptoms that can last for months or even years. It is too early to know how often an Omicron infection causes long-term COVID, especially in people who have been vaccinated.
To keep up with the evolving virus, other experts said, COVID vaccines must be updated more quickly, even faster than the flu vaccine each year. He said that even an imperfect match with a new form of coronavirus would still broaden immunity and provide some protection.
“Every time we think we’ve been through it, every time we think we have the upper hand, the virus pulls a trick on us,” Anderson said. “The way to get it under control is not to be like, ‘Let’s get infected a few times a year and then hope for the best.
