Study shows Omicron greatly reduces Covid antibody protection

December 9, 2021: -South African scientists say the Covid omicron variant significantly reduces antibody protection generated by Pfizer and BioNTech’s vaccine. However, according to a small preliminary study released Tuesday, people who have recovered from the virus and received booster doses will likely have protection from severe disease.

Prof. Alex Sigal with the Africa Health Research Institute and a team of scientists tested blood samples of 12 people vaccinated with the Pfizer/BioNTech vaccine. They look specifically at how the antibodies generated by the vaccine can neutralize the new variant, meaning block its ability to infect cells.

They found a 41-fold drop in the ability of the antibodies to neutralize the omicron variant compared with the original virus, a dramatic reduction from its performance against the original ancestral strain and other variants, according to a preprint of the study that has not yet been peer-reviewed. Vaccine-induced antibodies drop threefold in their ability to neutralize the beta variant that dominated South Africa, which suggests omicron is much better at evading protection.

“The results we present herewith Omicron show much more extensive escape” than the beta variant, researchers wrote. “Previous infection, followed by vaccination or booster is to increase the neutralization level and confer protection from severe disease in Omicron infection.”

The study tested 14 plasma samples from 12 vaccinated people, six infected. Scientists must make their Covid research available before going through the extensive peer-review process due to the urgency of the pandemic.

Dr. Paul Offit, professor of pediatrics at the Division of Infectious Disease at Children’s Hospital of Philadelphia, told CNBC the data are suggesting fully vaccinated people may be facing a higher risk of mild infection from omicron compared to the past variants.

“I think that there’s still going to be protected against serious illness,” Offit said. “I think with either vaccination or natural infection or both. You’re going to be protected against serious illness.”

Pfizer CEO Albert Bourla said that the company can develop a vaccine that explicitly targets omicron by March 2022 if needed. Bourla said it would take some weeks to get more definitive data on whether the current vaccines provide enough protection against the variant.

The Pfizer CEO had told CNBC that the protection provided by the company’s two-dose vaccine would be declined some in the face of omicron.

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First identified in southern Africa, Omicron has dozens of mutations that generally make viruses more contagious. White House chief medical advisor, Dr. Anthony Fauci, told reporters in a White House Covid briefing Tuesday that data from South Africa on omicron infections “clearly argue towards a high degree of transmissibility.”

Fauci said Tuesday it is too early to conclude whether omicron causes more severe disease, though he said that earlier reports were encouraging over the weekend.

In a report published Saturday, the South African Medical Research Council found that most patients admitted to a hospital in Pretoria who had Covid did not need supplemental oxygen, as was common in previous infection waves. According to the report, many patients in the Covid wards were hospitalized for other reasons.