May 30, 2024

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More COVID-19 variants such as Delta plus and Lambda are coming?

More COVID-19 variants such as Delta plus and Lambda are coming?



More COVID-19 variants such as Delta plus and Lambda are coming? Variant strains came one after another, how strong are Delta+ and Lambda?

At present, the world most needs to reach a consensus to decide how to improve existing vaccines against new mutant strains.

While the delta variant is becoming the dominant strain in more and more countries, other variants of the new coronavirus are gradually spreading around the world. Variants that have received more attention include Lambda, the first discovered in Peru, and Delta plus, a sub-variant of Delta. Whether the vaccines currently in use can withstand the invasion of new variants has also become the focus.

Lambda has a stronger immune escape ability against vaccines than the Delta variant, so it is more prone to breakthrough infections, but it is not clear whether it can become a dominant strain. At present, the world most needs to reach a consensus to decide how to carry out the next step of vaccine research and development for new mutant strains.




Lambda variant: The current spread is not as wide as DELTA variant

The Lambda variant of the COVID-19 virus (C.37) was first discovered in Peru in August 2020 and is currently spreading to 41 countries and regions around the world. The World Health Organization designated it as a “variant of interest” in June this year, which is inferior to the “variant of concern” to which the Delta variant belongs.

Since April this year, about 81% of confirmed cases of COVID-19 in Peru have been infected with the Lambda variant. According to data from the Global Shared Influenza Data Initiative (GISAID), the United States has confirmed 1,060 COVID-19 cases infected with the Lambda variant. Japan’s Ministry of Health, Labour and Welfare also reported on August 6 that a woman in her 30s who arrived at Japan’s Haneda Airport from Peru on July 20 was tested positive for the COVID-19 virus and was the first case of “lambda” infection in Japan.

Researchers from the University of Tokyo in Japan said that the lambda variant is highly infectious and more resistant to vaccines. In research conducted in the laboratory, they found that three mutations (RSYLTPGD246-253N, 260L452Q and F490S) of the Lambda variant can help it resist vaccine-induced neutralizing antibodies, and the other two mutations (T76I and L452Q) strengthen the The contagiousness of the Muda variant.

Pablo Tsukayama, PhD in molecular microbiology at Cayetano Heredia University in Lima, Peru, said that when the Lambda variant was discovered, it “did not attract much attention”. However, by March 2021, 50% of new cases in Lima were infected with the Lambda variant, and the proportion rose to 80% one month later. Tsukyama told Al Jazeera: “The jump from 1% to 50% is a preliminary indicator of the emergence of a more powerful variant.”

However, Preeti Malani, chief health officer of the infectious disease department at the University of Michigan in Ann Arbor, told CNN that the lambda variant is worrying, but even though it has been spreading for several months, this variant is still in the United States. Quite rare.

Lambda’s immune escape to vaccines is more severe than that of Delta, so it is more prone to breakthrough infections. But it is still relatively limited to spread in Peru, and the spread is not as fast as Delta. As for whether it can become a dominant strain, it depends on its fitness. The Lambda variant has not yet reached this level.

If you want to change from a “variety of concern” to a “worrying variant”, this means that the strain is particularly transmissible, or that the vaccine has a particularly strong escape performance. But now the Lambda variant is not a particularly big danger, just keep your eyes on it.



Delta plus: Stronger drug resistance of subvariants?

Delta+ is a sub-variety of Delta first discovered in India. The main difference is the mutation named K417N. India listed Delta+ as a “worrying variant” in June, but agencies such as the US Centers for Disease Control and Prevention and the World Health Organization have not yet taken similar actions.

According to statistics from the COVID-19 database, Delta+ has spread to at least 32 countries, including India, the United Kingdom and the United States. India has found more than 70 patients infected with delta + variants. South Korea also notified the country’s first two cases of Delta+ Covid-19 on August 3. One of the patients in their 40s had no recent travel history, and the other patient returned to South Korea from the United States on July 23. Both patients have been vaccinated against AstraZeneca’s COVID-19 vaccine.

The Indian Ministry of Health cited research saying that Delta+ is more transmissible than most of the COVID-19 variants, and is easier to bind to lung cells, and may be resistant to therapies used to treat COVID-19.

And British public health policy modelling and analyst Colin Angus (Colin Angus) said that this virus does not seem to have the ability to become the dominant strain in the UK. K417N mutations have also been found in some subvariants of the alpha variant of the new coronavirus, but they are less competitive than other variants of the new coronavirus.

Can vaccines protect against new variants?

A study by the Grossman School of Medicine of New York University showed that Beta, Delta, Delta+ and Lambda variants showed only “moderate” antibodies to the two mRNA COVID-19 vaccines induced by Pfizer/BioNTech and Moderna. Resistance indicates that the vaccine is still effective.

Angus also pointed out that cases of Delta+ infection are mainly young people. Preliminary data show that the antibodies produced by vaccinators are still effective against this mutation. The current data sample size is small. Although Delta+ has appeared in several countries with high vaccination rates, there is no evidence that it is more dangerous than Delta.

Some medical experts said that the world has not changed the vaccine against the new strain because everyone has not reached a consensus and believes that the existing vaccine is still effective against the delta variant. With a relatively mature technology background, when there is a real need, just give the vaccine production company about three weeks to replace them all.

The question that needs to be solved at present is: What is the method to deal with the new strain? Is it to develop a new vaccine that only fights against the new strain, or to mix it with the original vaccine and use two or three mixed? There is one epidemic strain in South America and another epidemic strain in Asia. Which vaccine should be used according to which? How will the world change? This also requires a consensus among the academia, industry, and regulatory agencies.


(source:internet, reference only)

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