Everything that is known about omicron (and the other variants of the coronavirus)


Americans, already tired by a pandemic that lasts almost two years, received a new blow during the long Thanksgiving weekend: the announcement of the appearance of a new variant of the coronavirus.

The omicron variant, officially known as B.1.1.529, appeared in November in several southern African countries. Alarms sounded around the world as South African public health officials saw it beginning to outgrow delta, the dominant strain so far.

This suggested that omicron could become widely spread. In fact, cases have since been reported on several continents, probably due to the international travel of infected people unknowingly.

Following the announcement of omicron’s emergence, several countries imposed travel bans in hopes of containing the virus. Whether those bans will effectively curb the spread is still unknown. “Travel bans do not help once cases have been detected, as we have seen before and are seeing now,” said Tara Smith, an epidemiologist at Kent State University.

Scientists warn that it is still too early to know if omicron will be as dangerous as delta. Other variants that initially seemed worrisome have faded.

For now, this is what is known, and what is not, about the omicron variant.

What is a variant?

A variant of a virus is one that has mutated in a way that increases its spread or severity compared to the original strain that emerged in Wuhan, China. “RNA viruses, like the coronavirus, can mutate when they replicate, especially when circulating at high speed,” explained Dr. Monica Gandhi, a professor of medicine at the University of California-San Francisco.

Coronaviruses do not mutate as easily as flu viruses, but they do mutate over time. The variants usually produce the same range of symptoms as the original strain of the coronavirus. But they can also help the virus spread more effectively from one person to another, or have an advantage in circumventing natural immunity or that of vaccines.

What variants were already circulating in the United States?

To date, public health officials have noted five “variants of concern”, in addition to two “variants of concern” that are not yet considered to be of concern. So far, no variant has emerged that fits into the most worrying of the three official categories: “high consequence variants.”

See also  Can excess triglycerides in the blood be stopped?

The World Health Organization (WHO) decided earlier this year to name the variants with Greek letters, both to simplify the debate and to avoid the stigma that a variant bears the name of a country.

The first four “worrisome variants” – alpha, beta, gamma, and delta – have been circulating in the United States for most of this year. But the most dominant variant has been delta, due to its ability to spread from person to person more rapidly than the others. For months, delta has accounted for more than 99% of coronavirus infections in the United States.

As of noon on November 29, there were no confirmed cases of omicron in the United States, but experts caution that it is only a matter of time. In fact, it could already be in the country without being detected.

How did omicron come about?

Although scientists are not sure where omicron first appeared, it was most likely in a southern African country.

Experts say that low vaccination rates in that part of the world likely helped create a favorable environment for omicron mutations.

“Many countries in Africa have populations with very low immunity: 30% in South Africa are vaccinated,” Smith said. “In a largely non-immune population, the virus can ravage, and each newly infected person is an opportunity for it to mutate.”

Why did public health authorities react so urgently to omicron?

The concern stems from the scope and nature of the mutations in the new variant. South African health authorities noted 50 notable mutations, 30 of which are in the spike protein (pike), a key structure of the virus, New York magazine reported. This is more than the previous variants have had.

“If we look for mutations that affect transmissibility, it has them all,” Oxford University biologist Aris Katzourakis told Science magazine.

However, what is not clear at this time is the efficacy of these mutations in creating a variant that can consistently outperform delta.

What do we know about how contagious omicron is?

The omicron variant is so new that scientists are just beginning to understand its characteristics. Therefore, experts ask for caution when drawing conclusions, especially from anecdotal evidence.

That said, the scientists say they wouldn’t be surprised if omicron becomes as easily transmissible as delta.

“The answer is uncertain, of course, but it looks like it will be at least as infectious as delta,” said Dr. William Schaffner, professor of preventive medicine at Vanderbilt University School of Medicine.

Complicating the situation, according to Schaffner, is that the fastest-spreading initial areas have been in areas of Johannesburg populated by young adults and college students, which tend to have lower vaccination rates. The vulnerability of these groups to infection may be overstating how quickly omicron appears to be spreading.

See also  10 common myths and doubts about psoriasis

Is it known if omicron generates a more serious form of covid?

Early evidence is somewhat mixed, but there are indications that omicron symptoms may not be more severe than previous variants. Dr. Angelique Coetzee, who chairs the South African Medical Association, has said that the first cases that are being seen among the unvaccinated are mild.

However, it remains to be seen whether older, poorer patients also have mild symptoms. Another issue is that it may be too early in the spread of omicron to see cases that have seriously progressed.

Will existing vaccines be effective against this variant?

Scientists are cautiously optimistic that existing vaccines will also be effective against omicron, just as they have been against delta, at least in terms of their ability to prevent a disease severe enough to require hospitalization.

“Scientists from South Africa and Israel, where the variant has also been detected, have indicated that no serious disease develops among those vaccinated,” Gandhi said.

Gandhi added that the immunity-providing B cells generated by vaccines have been shown to produce antibodies against the variants, and that the immunity of the T cells, which protect against severe disease, is robust and should not be at risk from the mutations being observed in omicron.

The vaccines also produce polyclonal antibodies that act against multiple parts of the spike protein, he explained. Finally, boosters have been shown to be effective in building immunity quickly.

“Most scientists believe that we should continue to have protection against severe disease with vaccines, and vaccination remains the mainstay of control,” Gandhi said.

They recommend that people get vaccinated, and, if they are already vaccinated, give themselves the booster.

How long will it take before the omicron threat is controlled?

Moderna, Pfizer-BioNTech and Johnson & Johnson are testing the efficacy of their omicron vaccines in the laboratory, based on variant testing protocols developed earlier this year. Results should be available in a week or two.

Other questions, such as whether omicron is sicker and more communicable, will take longer to answer because they require careful contact tracing and accurate diagnosis of those infected.

To better answer these questions, Smith stated: “I think it will take at least a month to get some preliminary data, and quite possibly more time to get a better idea of ​​the situation. Neither will we know the real experience of the advances in vaccines until that moment ”.

Can we wait for a new omicron-specific booster to be developed?

It is unknown if the omicron variant will require a reformulated booster. In the case of the delta variant, no further boost was necessary as the researchers determined that the existing formulation was still effective.

See also  There's no cure for a hangover, according to new research

That being said, vaccine manufacturers can release a new booster quickly if needed.

In the event such a variant emerges, Pfizer and BioNTech “hope to be able to develop and produce a custom vaccine against that variant” within 100 days, pending regulatory approval, a Pfizer spokesperson told The Washington Post.

Dr. Matthew Laurens, a pediatric infectious disease specialist at the University of Maryland School of Medicine, said he is confident that boosters can be quickly developed and tested if needed, “probably within a few months.”

What happened to the other variants?

Between May 2021, when delta was named a worrying variant, and November 2021, when omicron received the same label, two other variants were declared “variants of interest”: lambda from Peru and mu from Colombia. Other variants, such as one discovered in Nepal called “delta-plus”, also attracted attention during this period. But none of them managed to consistently outperform delta, so they were never upgraded to “worrying variants.”

Here’s what to expect from omicron. The other variants “came up with similar concerns, but did not expand significantly after the initial report,” Gandhi noted.

Is it reasonable to think that the United States is in a better position to control omicron than it was with delta?

Experts generally agree that the United States should be better prepared to fight omicron than when delta emerged earlier this year.

“We are in a much better position, as we have higher vaccination rates, the availability of boosters for everyone over the age of 18, and vaccine eligibility starting at age 5,” Gandhi said. “We also have higher rates of natural immunity in the country due to the spread of the delta variant since July 2021. And we have an oral antiviral therapy on the horizon. So we have the tools to combat this new variant ”.

The challenge, Schaffner said, will be to make sure that Americans continue to be vaccinated and receive reinforcements; get tested and behave safely in public.

“All of these tools are available,” he said. “The big question is to what extent the general public is willing to use them.”

Is the coronavirus going to be permanent, like the flu?

Experts believe that the coronavirus is unlikely to be eradicated from the world, as smallpox has been, or even eliminated in the United States, as was polio after near-universal vaccination. The combination of rapid mutations and excessively low vaccination rates means that COVID-19 may not follow smallpox and polio on the path to eradication.

“It’s more likely to follow the flu model, where we have to track mutations annually and modify boosters accordingly,” Schaffner said. In fact, he concluded, work is already underway on the creation of combined vaccines against coronavirus and flu.

Leave a Comment

Your email address will not be published.