We could all get COVID, but the key is when

By Faye Flam

January 2022 is one of the worst possible times to contract COVID-19. That’s not just because hospitals are dangerously crowded, but because after nearly two years of gradually learning more about SARS-CoV-2, the omicron variant has caused scientists and doctors to slip back into a state of ignorance. and assumptions. Tests and treatments are scarce. But we are not in March 2020 again; in fact, the situation is likely to improve dramatically in a matter of a couple of months.

Ómicron seemed to come out on the wrong side. Scientists had predicted that, should new variants appear, these would likely be derivations of the delta variant, since that variant accounted for the majority of infections worldwide, but omicron is a distant cousin that no one knew existed until it rose to an alarming rate in South Africa.

Scientists are still trying to figure out whether the decline in the delta variant is due to the omicron wave, or if omicron is simply making delta appear small in comparison. And more generally, they want to know how the new variants become dominant, as this is a phenomenon that could happen again.

“It is somewhat mysterious why these sudden waves arise and one variant completely replaces the other ”, said Jeremy Luban, an infectious disease specialist at the University of Massachusetts School of Medicine. “We saw that that was what happened with Alpha when it first appeared, it was quite alarming”.

There is evidence that immunity is allowing omicron to roll back its predecessor. Recent unpublished data from a well-known group in South Africa shows that omicron infection leaves people with an immunity that protects against the delta variant. Cross immunity between variants works much better in this direction. People infected with delta appear to have very little protection against omicron.

That asymmetric immunity would clearly give omicron an advantage, but it is still unclear if it is possible for the delta variant to hide somewhere and return later, perhaps in an altered form that evades the omicron variant’s antibodies.

Luban said the omicron infections are also likely preventing the delta variant from spreading to new hosts. “Viruses, once they enter cells, can block the entry of other viruses”, He indicated. They don’t like sharing guests. Ómicron seems to be a lot more contagious, which is why he’s winning this race.

These fundamental questions have great practical implications. For example, monoclonal antibody drugs that saved lives and truncated disease previously in the pandemic are no longer offered in most places because they do not work against omicron, which responds to a different drug. And few hospitals have the resources to test each patient to see if they have an omicron or a delta, which is not yet fully extinct.

Then there is the question of why and how omicron spreads much more easily than other variants. It doesn’t seem to leave people with a higher “viral load“But it could persist at levels that keep people contagious longer, said Mark Siedner, an epidemiologist and infectious disease clinician at Massachusetts General Hospital.

That’s a sore subject now that the CDC shortened the length of its isolation and quarantine recommendations, and questions are emerging about the ability of rapid tests to detect cases early enough to stop contagion.

Siedner is participating in a study that aims to measure how long people continue to be contagious after contracting COVID by omicron. PCR tests are known to be positive for days to weeks after people have shed the live virus, because the test can detect inert debris of viral RNA. So your group will test people who have tested positive every other day for several weeks to see if they can isolate samples of the virus that are still viable.

That data could help the CDC formulate better guidelines on isolation and quarantine. “I hope that next week, or two weeks, we can show quite clearly how long people continue to be contagious with omicron“, He said. “I know that the CDC asks us to isolate ourselves for five days … That people remain contagious for 10 to 15 days … it could explain some of what we are seeing. “

So scientists won’t stay in the dark about the omicron variant forever, not even for much longer. And after this winter wave is over, it will be easier for everyone to get tested and easier for the sickest to get the right monoclonal antibodies. In just a couple more months, doctors hope to have antiviral pills that will work against all known variants.

Some experts have warned that almost everyone will contract this virus in one form or another in the long run, and that may be the case if it persists for decades. But the moment in which that happens is key.