Why firm answers about Omicron’s impact could take weeks – Boston, Massachusetts

Boston, Massachusetts 2021-11-28 10:02:58 –

NSHis appearance Omicron variant of coronavirusWith a series of mutations that suggest that it may be extra contagious and avoid at least some degree of immune protection, the world is eager for an answer as to what it means for the Covid-19 pandemic. increase. However, much remains unknown, largely because variants appear to be detected and published very quickly.

With other variantsIt has been several months since they were first documented before being designated as a “variant of concern”. In some cases, scientists have more opportunities to understand them before they are widely noticed. In Omicron, first identified as B.1.1.529, everything happened within about two weeks.

As they compete to initiate more rigorous research, scientists are currently trying to gather insights from South Africa’s limited epidemiological evidence and the list of mutations acquired by the mutants. Immune protection. This variant is also noteworthy for its vast number of mutations. It teaches the vaccine to target the immune system because it contains only 32 peplomer proteins. Other variants had only a handful of mutations in spikes.


“There is a lot of research going on right now,” said Maria Van Kerkhove, technical leader of the World Health Organization’s Covid-19, on Friday. “In South Africa and other countries, infectiousness, severity, and diagnosis, treatment, or vaccine. Little information is available so far, but those studies are ongoing and researchers will implement them. You need to set aside time. “

“It will take days or weeks for some of these studies to be carried out,” she added.


Scientists who have done early work on Omicron emphasize that it is unclear whether this variant will have significant global impact. But they have a reason for concern, which is why they are encouraging countries to prepare and act early.

So far, perhaps the most pressing question about Omicron is: Is it more contagious than the delta variant? And to what extent can it circumvent the immune protection generated by previous infections and vaccines?

When it comes to transmissible questions, experts are closely watching how Omicron continues to play an active role in South Africa and elsewhere.

Early epidemiological data suggested that Omicron was competing ahead of the South African Delta, and that Delta was replacing it faster than other variants. (The potential spread advantage is that the variants are inherently more contagious and can cause infections in other versions of the virus, or in people who are protected at a higher rate than the combination of the two. May mean.)

South African Covid-19 levels were suppressed when the variant was first detected. Since then, the numbers have skyrocketed. This could mean that Omicron has a growth advantage over Delta, but it could also be riding on a new surge in cases rather than driving it. Some scientists hypothesize that the increase in cases was driven by several hyperdiffusion events and explain why surges were first detected primarily in Gauteng. According to WHO, cases of this subspecies are currently increasing nationwide, but some of the increase may be related to which infection is being sequenced.

If Omicron establishes a foothold in other countries and also precedes Delta, it will help solidify the idea that it is more contagious.

To determine if variants can weaken the immunity produced by vaccines and infections, scientists can draw antibodies from people’s blood and test them against Omicron. .. However, it takes time to grow variants in the lab and build versions designed to act as a model for viruses.

WHO said on Saturday that early evidence indicates that this mutant causes a higher rate of reinfection than other South African mutants, suggesting its ability to evade an immune response. He said he was.

“In South Africa, there is a rapid stream of studies investigating the antibody neutralization of this variant and its interaction with T cells, but these studies will take weeks to complete,” Covid-19 said. Said Sharon Peacock, director of the. Genomics UK Consortium. She described the variant as having “some aspects of concern” but having “many unknowns”.

In new variants, the vaccine can lose the step of stopping the infection. Especially when the inducing antibody cannot recognize the virus, it has a broad immune response that largely maintains its ability to prevent severe illness and death. Contains T cells. This has already occurred to varying degrees in other variants, the largest range in beta variants, and to some extent in deltas. With a high degree of antigenic escape, a high proportion of breakthrough cases can lead to serious consequences. It does not mean a complete vaccine failure, but it does mean a decrease in the effectiveness of the vaccine.

South African health minister Joe Phaahla said on Friday that breakthrough infections were occurring in the country, but most of the hospitalizations remained among unvaccinated people and the vaccine still had some protection against Omicron. It suggests that it is maintaining. However, he admitted, “We are still in the early stages of this particular variant.”

There is also a question as to whether Omicron causes the same disease severity on average as other variants. The study looks at the proportion of people who have Omicron and are hospitalized or die compared to Delta and other variants.

Omicron was first identified primarily in Botswana and South Africa, but did not necessarily appear there. These countries have strong sequencing networks, so they were in a good place to detect new variants. Nonetheless, many countries, including the United States, have announced restrictions on travel from these countries and their neighbors in southern Africa.

Studies show that travel restrictions can delay the arrival of variants of viruses such as SARS-CoV-2, but they do not necessarily prevent them. Example: This variant was detected in some European countries even after the travel ban was announced.

Pathogens generally follow a pattern of migration as they spread, but there is also a lot of randomness as to whether and when mutations occur at specific locations. Some imported infections go nowhere, but other infections cause a series of infections. The more cases it is introduced, the more likely it is that the fire will spread.

Omicron also emphasizes the sometimes competing priorities of vaccine campaigns. In wealthy countries with large stockpiles of vaccines, the need for qualified people to obtain booster shots increases. If the mutant can avoid some degree of immunity from the primary series, boosters may help stimulate the immune system enough to fend off highly mutated forms of the virus.

More contagious viruses will exacerbate the plight of countries with limited vaccine supply. Already, supporters have shown that the emergence of Omicron shows what happens when the world has such an unfair distribution of vaccines, and at such high levels in certain parts of the world. He claimed that he was allowed to continue the infection in.

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