Omicron variant partially dodged vaccines in blood study – .

Omicron variant partially dodged vaccines in blood study – .

South African researchers reported on Tuesday that the Omicron coronavirus variant appears to dodge vaccines, but only partially. The results, from a small lab study, suggest that people who have recovered from COVID-19 and been vaccinated will retain strong protection, but those who received only the two-dose vaccination schedule could be significantly more vulnerable to infection. The study did not examine the effects of boosters but suggests that their protection may be important against Omicron.

Since the Thanksgiving holiday, concern has grown around the world over the appearance of the Omicron variant, which is showing signs of increased contagiousness compared to other COVID-19 variants. Originally reported in South Africa, there are now case reports in more than 50 countries and at least 19 US states, to date.

The new finding from the Africa Health Research Institute (AHRI) in Durban, South Africa is in some ways reassuring for people who have had both their vaccines and a previous infection with COVID-19, experts said external, and suggests increasing booster injections as a priority. But the discovery – which experts warn is preliminary – raises concerns for those whose antibodies induced by the initial vaccination may be on the decline.

“I think we’re in a situation where we were all hoping we would report something different,” said Jacob Lemieux of Harvard Medical School.

“But the reality is that the data suggests that this is a more transmissible virus with high degrees of immune evasion, which will make vaccines less effective, and most monoclonal antibodies ineffective, coming from a virus. push on a push to a really tough time, ”Lemieux said, citing concerns about an increase in variations as vacation travel increases before Christmas and New Years.

In the new study of blood samples taken from a dozen people previously vaccinated with the Pfizer-BioNTech mRNA vaccine, researchers led by Alex Sigal of AHRI found that their antibodies were not enough to “neutralize” the variant in half of them – those who had never had an infection before.

However, half of the study participants had previously been infected with COVID-19. Of these six participants, five of them saw a “relatively high neutralization” against the variant.

Sigal said in un tweet that the result was “better than I expected for Omicron,” showing that the variant was still vulnerable to vaccines overall and that it infected cells in a similar way to the other variants. Showing that the variant only partially escaped vaccines, the study also suggested that the injections should remain effective against serious illness, especially when supplemented with a booster.

That said, the results overall reported a 40-fold decrease in antibody activity against the Omicron variant compared to neutralization of vaccine antibodies to the original strain of the coronavirus SARS-CoV-2, a much larger breakout than that. observed with other variants.

The blood plasma study is still a preliminary version and has not yet been peer reviewed by other scientists, so there is some caution but not enough to outweigh its topicality, experts said.

“I think there is a consensus among us that even though the numbers are low, they come from a reputable lab that has already done this and are not surprising,” said the infectious disease expert. Bruce Walker of the Massachusetts Consortium on Pathogen Readiness.

“The effects are not subtle. So it is likely that this is correct.

Earlier in a White House briefing, the head of the National Institute of Allergy and Infectious Diseases, Anthony Fauci, described very preliminary reports from South Africa of increased transmissibility of variant, as evidenced by the increase in cases of reinfection among people previously infected with Beta and Delta variants.

Fauci also described the results of a “very preliminary” study, also in South Africa, that the Omicron variant tended to produce less severe disease than previous ones. “I hope that in the next few weeks we will have a much clearer picture,” he said. “But it seems that with the cases that are observed, we don’t see a very severe disease profile. In fact, it could be – and I emphasize force – be less severe, as shown by the ratio of hospitalizations per number of new cases.

A much more transmissible but only slightly less dangerous version of COVID-19 would still overwhelm hospitals in an increased wave, noted Lemieux, a researcher at Harvard Medical School. In past outbreaks, death rates have increased as hospital intensive care units fill up.


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