Study Details How to Get Rid of the Delta Variant Immune System


Delta variant coronavirus It can evade antibodies that target certain parts of the virus, according to a new study published Thursday in Nature. The findings offer an explanation for the decreased efficacy of the vaccines against Delta when compared with other variants.

The variant, first identified in India, is believed to be around 60 percent more contagious than Alpha, the version of the virus that shook the UK and much of Europe earlier this year, and perhaps twice as contagious as the original coronavirus. Delta variant currently causing outbreaks among unvaccinated populations in countries such as Malaysia, Portugal, Indonesia and Australia.

Delta is also now the dominant variant in the United States. Infections in the country were at their lowest level since the start of the pandemic, though their numbers are increasing. Still, hospitalizations and deaths due to the virus continued to decline steeply. This is partly due to relatively high vaccination rates: 48 percent of Americans are fully vaccinated, and 55 percent have received at least one dose.

But the new study found that: Delta was barely sensitive to someone vaccine doseconfirms previous research suggesting that the variant may partially evade the immune system – albeit to a lesser degree than Beta, variant It was first described in South Africa.

French researchers tested how well antibodies produced by natural infection and coronavirus vaccines neutralized Alpha, Beta and Delta variants, as well as a reference variant similar to the original version of the virus.

The researchers looked at blood samples from 103 people infected with the coronavirus. Delta The study found that it was much less sensitive to samples from unvaccinated people in this group than Alpha.

One dose of the vaccine significantly increased sensitivity, suggesting that people recovering from Covid-19 still need to be vaccinated to fend off some variants.

The team also analyzed samples from 59 people after taking the first and second doses of the drug. AstraZenecone or Pfizer-BioNTech vaccines.

Blood samples from only 10 percent of people vaccinated with one dose of AstraZeneca or AstraZeneca Pfizer-BioNTech vaccines they were able to neutralize Delta and Beta variants in laboratory experiments. But a second dose increased that number to 95 percent.. There was no significant difference in antibody levels elicited by the two vaccines.

“A single dose of Pfizer or AstraZeneca was either weak or not effective at all against the Beta and Delta variants,” the researchers said. Data from Israel and the UK largely support this finding, but these studies show that one dose of the vaccine is still sufficient to prevent hospitalization or death from the virus.

The delta variant also did not respond to bamlanivimab, the monoclonal antibody made by Eli Lilly, according to new research. Fortunately, the other three monoclonal antibodies tested in the study retained their efficacy against the variant.

In April, the U.S. Food and Drug Administration citing the rise of variants resistant to bamlanivimab. revoked emergency use authorization Due to its use as a single treatment in the treatment of Covid-19 patients.


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