Omicron not more severe than Delta, existing vaccines will work: WHO

Meanwhile, researchers in South Africa have found that Pfizer's Covid-19 vaccine actually provides less immunity to the Omicron variant than to other major versions of the virus.

Amid mounting global concerns over Omicron, the new variant of the coronavirus disease (Covid-19) said to be more transmissible and capable of undergoing frequent mutations, the World Health Organisation (WHO) has laid to rest apprehensions about the efficacy of existing vaccines against the new strain. A top WHO official told the AFP news agency on Tuesday that there is no reason to assume that Omicron is more severe than the variants which came before, or that existing vaccines will fail against it.

Omicron’s rapid spread in South Africa has raised concern that the immune protection from vaccination may not be enough, but experts disagree. (REUTERS / File Photo)

Michael Ryan, the World Health Organisation's emergencies director, told AFP in an interview that there currently is no indication to suggest that Omicron, although highly infectious, causes a more severe disease than previous Covid-19 variants such as Delta. The existing vaccines should protect people who contract Omicron against the worst outcomes of the disease, he said.

“We have highly effective vaccines that have proved effective against all the variants so far, in terms of severe disease and hospitalisation, and there's no reason to expect that it wouldn't be so [for Omicron],” the WHO official was quoted as saying.

Ryan, however, said that more research was needed into studying the Omicron variant to appropriately take on board exactly how threatening it is poised to be. 

A similar assurance was echoed on Tuesday by US infectious diseases expert Anthony Fauci, who said that Omicron is certainly not worse than the previous strains, including Delta.

According to the chief medical advisor to the US president, Omicron is “clearly highly transmissible” but might actually be less severe than Delta, as indicated by the ratio between the number of infections and the number of hospitalisations in South Africa.

Fauci, too, said that more epidemiological data from around the world is needed to affirm scientific consensus on this. The results from lab experiments that tested the potency of antibodies from current vaccines against Omicron should come in the next few days to a week, he added.

Meanwhile, researchers in South Africa have found that Pfizer's Covid-19 vaccine actually provides less immunity to the Omicron variant than to other major versions of the virus. The loss of immune protection is “robust, but not complete,” Alex Sigal, head of research at the Africa Health Research Institute in Durban, said in an online presentation of the first reported experiments gauging the effectiveness of the vaccine against the new variant.