They detected why the Delta variant requires extreme health protocols

Delta It is the worrisome variant of the coronavirus that affects humanity the most. It was first detected in India in October last year and has so far been reported in at least 170 countries. It is also already in the South American region, and several countries already have local circulation of the variant: Argentina, Brazil, Chile, Colombia, Ecuador, Paraguay and Peru. Its impact could change the course of the pandemic for months to come.

A study of scientists from the UK, Switzerland, Japan, India and South Africa confirmed that Delta it supplanted the other variants which circulated not only because of its greater capacity to infect but also because neutralizing antibodies in humans have a lower sensitivity. So, Delta infection is more difficult to control.

The study was published in Nature and makes a recommendation: suggests that control measures such as distancing, proper use of the chinstrap, ventilation of confined spaces may have an effect on prevention if they are in addition to the COVID-19 vaccination of the population.

The research team included Ravindra Gupta, from the Department of Medicine, University of Cambridge, UK, and the African Institute for Health Research, Durban, South Africa. Gupta was voted one of the 100 most influential people in the world by Time magazine last year.

With Petra Mlcochova and other researchers, Gupta has now published the collaborative work with other researchers: They conducted a series of tests with more than 130 Indian healthcare workers between March and April.as well as lab tests to understand how the Delta variant infects human tissue compared to other variants, including the Alpha variant, which was also detected in the UK in October last year.

The researchers found that the 130 healthcare workers infected with the Delta variant did not have a higher risk of hospitalization, but were more likely to have a post-vaccination infection of this variant compared to others. . According to Dr Gupta, the Delta variant replicates better in lung cells than the Alpha variant.

Among the various research results, scientists have found that compared to the original variant of the coronavirus detected in China in January of last year which carries the D614G mutation (against which current vaccines have been developed), The Delta variant was found to be six times less sensitive to antibodies from individuals who had recovered from a previous infection.

It has also been identified that the vaccine developed by the University of Oxford and the company AstraZeneca was less effective against the Delta variant compared to the other variants. Besides, it was eight times less sensitive to the antibodies produced in response to two doses of the vaccines developed by the companies Pfizer / BioNTech and AstraZeneca. Although scientists have pointed out the need for people to keep applying vaccines, because they also provide high protection.

In laboratory models of the human airway, the Delta variant was more efficient in replication than the Alpha variant, an advantage that is associated with the predominantly cleaved configuration of the Delta Spike protein. This protein also allowed the Delta variant to replicate and enter cells at a faster rate than the Kappa variant. This difference could explain Delta’s dominance.

“By combining laboratory experiments and epidemiology of infections in people who have already been vaccinated, we have shown that the Delta variant replicates and spreads better than other commonly seen variants. There is also some evidence that neutralizing antibodies produced following a previous infection or vaccination are less effective in stopping this variant ”, Dr Gupta said in a statement. And he recalled the situation in India earlier this year: “These factors likely contributed to the devastating epidemic wave in India during the first quarter of 2021, where up to half of the cases were people who had already been infected with a previous variant.”

Partha Rakshit of the National Center for Disease Control in Delhi, India, co-lead author of the study, also said: “The Delta variant has spread widely to become the dominant variant around the world as it spreads more quickly and infect individuals better. than most of the other variations that we have observed. It is also preferable to bypass existing immunity – either by previous exposure to the virus or by vaccination – although the risk of moderate or severe illness is reduced in these cases ”.

Meanwhile, another of the researchers, Professor Anurag Agrawal, from the CSIR Institute for Genomics and Integrative Biology in Delhi, added: “Infection of health workers vaccinated with the Delta variant is a major problem. Even if they only experience mild COVID-19 themselves, they run the risk of infecting people who have a suboptimal immune response to vaccination due to underlying health issues, and these patients could then be at risk of serious illness. There is an urgent need to study ways to improve vaccine responses against variants in health workers ”.

The research was supported by the Ministry of Health and Family Welfare, the Council for Scientific and Industrial Research and the Department of Biotechnology of India, and with funding from the Wellcome Foundation, the Medical Research Council and from the National Institute for Health Research in the United Kingdom. .

Due to the potential impact that Delta traffic can have, The the researchers point out in the journal Nature that it is important to continue to maintain measures to control the spread of the coronavirus as before: masks, social distancing, hand washing, and permanent ventilation. The authors conclude that their results highlight the need to develop strategies to improve vaccine responses against variants of the coronavirus.

A few days ago, a review of published studies on the variants of the coronavirus. It was made by Argentinian scientists Humberto Debat, of the National Institute of Agricultural Technology and the National University of Cordoba, Mariana Viegas, of Conicet and the Ricardo Gutiérrez Children’s Hospital, and Carolina Torres of the Institute for Research in Bacteriology and Molecular Virology of the Faculty of Pharmacy and Biochemistry of the University of Buenos Aires and Conicet. Among other aspects, what has been the dynamics of Delta’s spread around the world.

“The dynamics of propagation of the Delta variant were similar in all the countries where it entered and established itself: it was characterized by a period of approximately two to four weeks of sporadic detections until reaching 1 to 5%. cases, per month. it exceeded 50% and within six to eight weeks it reached frequencies above 90% of new infections. In other words, since its minority detection in cases of local transmission without epidemiological link with imported cases, Delta has become predominant and with an almost total displacement of the other circulating variants within the approximate timeframe of six to eight weeks ”, affirmed the scientists who form part of the project country’s genomic surveillance consortium, which reports to the Ministry of Science, Technology and Innovation of Argentina.

KEEP READING: