Omicron’s ability to evade vaccine and infection-induced immunity is “robust but not complete,” said the research head of a laboratory at the Africa Health Research Institute in South Africa.
In the first reported experiments gauging the effectiveness of Covid-19 vaccines against the worrisome new strain, researchers at the institute found that the variant could partially evade the vaccine produced by Pfizer and BioNTech.
Still, its evasion wasn’t complete and a booster shot could provide additional protection, Alex Sigal said in an online presentation on Tuesday.
Since South Africa announced the discovery of omicron on Nov. 25, about 450 researchers globally have been working to isolate the highly mutated variant from patient specimens, grow it in the lab, verify its genomic sequence, and establish methods to test it in blood-plasma samples, according to the World Health Organization.
Omicron’s rapid spread in South Africa has raised concern that the immune protection generated by vaccination or a previous bout of Covid-19 is insufficient to stop reinfections or stem a fresh wave of cases and hospitalisations. The WHO has warned omicron could fuel surges with “severe consequences” amid signs that it makes the coronavirus more transmissible.
The work in Sigal’s lab involved testing blood plasma from people who were vaccinated against Covid-19 to gauge the concentration of antibodies needed to neutralize, or block, the virus.
The results, along with those from other labs currently underway, will help determine whether or not existing Covid vaccines need to be altered to protect against omicron.
Sigal’s laboratory was the first to isolate the beta variant, a strain of the coronavirus that was identified in South Africa in late 2020.
