A virus that shows no signs of going away, variants good at dodging the body’s defenses and waves of infection two, maybe three times a year – this could be the future of Covid-19, some experts say. science worries.
The main problem is that the coronavirus has become more adept at regenerating the human body. Currently, people infected with the first Omicron variant are reporting a second infection with newer versions of the variant – BA.2 or BA2.12.1 in the US, or BA.4 and BA.5 in the US. South Africa.
These people could go on to have a third or fourth infection, even this year, the researchers said in interviews. And a small portion may have symptoms that persist for months or years, a condition known as persistent Covid.
“To me, that looks like a long-term model,” said Juliet Pulliam, an epidemiologist at Stellenbosch University in South Africa.
She added: “The virus will continue to evolve. “And there’s probably going to be a lot of people who get many, many re-esthetics over the course of their lives.”
It is difficult to determine how often people get reinfected, in part because many infections are currently unreported. Dr Pulliam and her colleagues have collected enough data in South Africa to say that rates in Omicron are higher than in earlier variants.
This is not how it is supposed to be. Earlier in the pandemic, experts thought immunity from vaccinations or previous infections would prevent most reinfections.
The Omicron variant has dashed those hopes. Unlike earlier variants, Omicron and many of its descendants appear to have evolved to partially evade immunity. That leaves everyone – even those who have been vaccinated many times – susceptible to superinfection.
“If we managed it the way we manage it now, most people would get it at least a few,” said Kristian Andersen, a virologist at the Scripps Research Institute in San Diego. times a year. “I would be very surprised if that’s not the way it is.”
The new variants do not change the basic usefulness of the Covid vaccine. Most people who have had three or even just two doses will not get sick enough to need medical attention if they test positive for coronavirus. And a booster dose, like the previous one, seems to reduce the chance of reinfection – but not by much.
From the outset of the pandemic, many experts based their coronavirus expectations on the flu, the viral enemy most familiar to them. They predict that, like the flu, there could be a major outbreak each year, most likely in the fall. The way to minimize its spread is to vaccinate everyone before it arrives.
Instead, the coronavirus behaves like its four close cousins, circulating and causing colds year-round. While studying the common cold coronavirus, “we’ve seen people become superinfected within a year,” said Jeffrey Shaman, an epidemiologist at Columbia University in New York.
If reinfection becomes normal, then the coronavirus “won’t simply be this winter once a year,” he said, “and it won’t be a mild annoyance given the amount of illness and death that is. cause.”
Improvements with earlier variants, including the Delta, have occurred but are relatively infrequent. But in September, the rate of reinfection in South Africa appeared to increase and was markedly high in November, when the Omicron variant was identified, Dr Pulliam said.
Revaccination in South Africa, as in the United States, seems even more remarkable because so many people have been vaccinated or infected at least once by far.
Dr Pulliam said: “Perceptions exaggerate what is actually going on biologically. “It’s just that there are more people eligible for reinfection.”
The Omicron variant is distinct enough from Delta and Delta from earlier versions of the virus, that some reinfection is expected. But now, Omicron appears to be developing new forms capable of penetrating immune defenses with relatively little change to its genetic code.
“This actually surprised me a bit,” said Alex Sigal, a virologist at the African Institute of Health Research. “I think we’re going to need a whole new kind of variation to get rid of this one. But in fact, it seems you don’t”.
Omicron infections produce a weaker immune response, which appears to rapidly wane compared with infections with earlier variants. Although the newer versions of the variant are closely related, from an immunological perspective they are so different that infection with one leaves little protection against the other variants – and certainly not after three or four months.
However, the good news is that most people who get refinished with the new version of Omicron won’t get very sick. At least for now, the virus doesn’t yet have a way to completely overcome the immune system.
“That’s probably as good as it is now,” Dr. Sigal said. “There is a big risk that the variation will be completely different.”
Each infection can carry with it the possibility of prolonged Covid, a range of symptoms that can persist for months or years. It’s too early to know how often an Omicron infection leads to persistent Covid, especially in vaccinated people.
To keep up with the evolution of the virus, other experts say, the Covid vaccine should be updated faster, even faster than the annual flu vaccine, other experts say. They said even an imperfect combination with a new form of coronavirus would extend immunity and provide some protection.
“Every time we think we have overcome this problem, every time we think we have the upper hand, the virus does a trick on us,” says Dr. Andersen. “The way to control it is not” Let’s all get infected a few times a year and then hope for the best. “
