Researchers studying the effects of Pfizer’s Covid-19 vaccine on the Omicron variant announced on Tuesday that the variant is partially capable of evading the vaccine’s protection.
The team, which has been working in South Africa since the discovery of the new variant, said that those who have recovered from Covid and are fully vaccinated, as well as those who have received a booster shot, are well protected against the variant.
The team conducted tests in lab dishes with samples from a dozen people who were fully vaccinated with Pfizer’s vaccine. The results indicated that Omicron is capable of escaping the vaccine’s protection– but only partially.
“There is a very large drop in neutralization of Omicron by BNT162b2 [Pfizer/BioNTech] immunity relative to ancestral virus,” said Alex Sigal, the study’s lead author, on Twitter. Sigal works for the Africa Health Research Institute in Durban.
“Omicron escape from BNT162b2 neutralization is incomplete. Previous infection + vaccination still neutralizes,” Sigal said.
Sigal told CNN that these results were much better than what he and his team had expected:
“I thought this news was very positive. I expected worse,” Sigal said in an interview. Many experts were expecting Omicron to almost completely bypass the protection of vaccines.
“This is not a variant that has completely escaped. It certainly escapes. It is certainly bad. But it looks to me like there are ways of dealing with it.”
The study analyzed human lung cells and blood to find their results. It has yet to be peer-reviewed.
“Previous infection, followed by vaccination or booster, is likely to increase the neutralization level and likely confer protection from severe disease in Omicron infection,” the study read.
Some of the samples had a 41-fold reduction in neutralizing antibodies deployed against the Omicron compared to the levels of antibodies present in earlier Covid-19 variants. But Sigal said that that number is fluid and subject to change with further tests and variables, including if the person had been previously infected.
Evidence Omicron produces less severe infections
The news comes as evidence is mounting that Omicron may be producing less severe infections than previous Covid-19 variants, like Delta.
On Saturday, the South African Medical Research Council published a report about an Omicron-driven outbreak in the Tshwane district in South Africa’s northern Gauteng Province, one of the first areas in the world where Omicron has overtaken Delta as the dominant strain.
The researchers wrote that in the last two weeks there has been an “exponential” rise in caseloads, but significantly, the surge has not corresponded to a significant uptick in hospitalizations and deaths.
“The relatively low number of COVID-19 pneumonia hospitalizations in the general, high care, and ICU wards constitutes a very different picture compared to the beginning of previous waves,” the report said, examining data from the Steve Biko and Tshwane District Hospital complex.
White House medical adviser Dr. Anthony Fauci said he is encouraged by the preliminary figures coming from South Africa.
“Though it’s too early to really make any definitive statements about it, thus far it does not look like there’s a great degree of severity to it,” Fauci said on CNN on Sunday.