Changed and changed new coronavirus variant "Delta" has an enhanced version.


　　Indian experts say that short-term contact may also be infected

　　Intern reporter Zhang Jiaxin


　　International war "epidemic" operation

　　Like all viruses, since the discovery of the new coronavirus, its infectivity, danger and the symptoms that it causes have changed as it continues to mutate.

　　World Health Organization (WHO) Chief Scientist Swaminatan recently stated that the transmission capacity of the "Delta" (δ/B.1.617.2) mutant virus strain has been significantly enhanced, and it is becoming a major global epidemic of new coronavirus mutant strains.

At present, "Delta" has attracted widespread attention around the world.

　　However, on June 11, the Public Health Department of the United Kingdom first reported a variant of the new coronavirus called "Delta Plus" (B.1.617.2.1/AY.1) in India.

The Public Health Department of the United Kingdom stated that at least 41 cases of "Delta Plus" have been detected in the United Kingdom.

The Ministry of Health of India stated on the 23rd that about 40 cases of this variant have been observed in the three states of Maharashtra, Kerala and Madhya Pradesh, but "the incidence has not increased significantly."

　　The latest news from New Delhi Television (NDTV) in India on June 25 stated that of at least seven confirmed cases of the "Delta Plus" variant of the new crown virus in Madhya Pradesh, two patients have died.

The doctor said that they had not received any vaccines.

　　"Delta Plus" was formed by mutation of "Delta"

　　The "Delta Plus" variant is similar to the original "Delta" strain. It is formed due to the mutation of the spike protein in the "Delta" variant. This new mutation is named "K417N", which helps the virus enter and Infect human cells.

　　Indian top virologist Shahid Jameel said that the K417N mutation is located in the receptor binding domain of the spike protein. This change is worth noting because this mutation also exists in the "beta" (β) variant that was first discovered in South Africa. in.

　　"India Express" reported on June 24 that "Delta Plus" is resistant to a mixture of monoclonal antibodies.

　　Up to now, the Global Shared Influenza Data Initiative (GISAID) has identified 63 genomes of the "delta" virus with the K417N mutation.

　　The Public Health Department of the United Kingdom reported that as of June 7, the "Delta Plus" variant was found in the genomes of six samples from India.

　　Currently in India, the frequency of K417N in variants is not high.

Most of these gene sequences come from Europe, Asia and America.

The earliest sequence of the genome was first discovered in Europe in late March this year.

　　Why the "Delta Plus" variant attracts attention

　　According to British Sky TV news on June 23, after India discovered 16 cases of "Delta Plus" in Maharashtra, India has listed the strain as a "worrying variant."

The Ministry of Health also expressed the same concern, saying in a statement: "The K417N mutation has aroused interest because it also exists in the'beta' variant. This variant is said to have immune evasion properties."

　　Previously, British experts said that the K417N mutation of the "beta" variant can help the virus avoid neutralizing antibodies.

This means that it will reduce the effectiveness of vaccines and antibody drugs and increase the risk of re-infection.

　　Jameel said that the K417N mutation will reduce the effectiveness of antibody cocktail therapy used to treat new coronary pneumonia.

　　US Consumer News and Business Channel (CNBC) reported on June 24 that the "Indian Coronavirus Genome Consortium" (INSACOG), composed of 28 laboratories, warned that the "Delta Plus" variant has 3 worrisome Features: enhanced infectivity, stronger binding to lung cell receptors and possible reduction of monoclonal antibody response.

　　Indian media livemint reported on June 25 that this variant is highly contagious, causing symptoms including dry cough, diarrhea, fever, headache, rash, discoloration of fingers and toes, chest pain and shortness of breath.

In an interview with Indian media, Randip Guleria, the head of the Indian Institute of Medical Sciences, said: "The'Delta Plus' variant virus found in India is extremely contagious, even in short-term contact with patients. , May be infected."

　　Is the vaccine effective for "Delta Plus"

　　India's "Economic Times" reported on June 24 that data showed that the prevalence of the "Delta Plus" variant virus in India is still very low.

So far, "Delta" is still the main variant of the country, and it is not yet certain whether "Delta Plus" will trigger the third wave of epidemic in India.

　　Medical experts say that it is too early to predict the effectiveness of existing vaccines against new variants.

To determine the impact of mutations on the immune system requires detailed research.

The British Public Health Department said last week that both Oxford-AstraZeneca and Pfizer vaccines are effective against the "Delta" variant, but more data is needed for the effectiveness of the "Delta Plus".

　　At present, the Indian Ministry of Health has recommended that the three states where "Delta Plus" is found "immediately take containment measures in various regions and clusters, including prevention of crowd mixing, extensive testing, rapid tracking, and priority vaccination."