Omicron More Transmissible Than Delta, Reduces Vaccine Efficacy: WHO

WHO noted that lack of data meant it could not say if Omicron's rate of transmission is higher because it is less prone to immune responses, due to higher transmissibility, or a combination of both.

The World Health Organization (WHO) said Sunday that the Omicron coronavirus variant is more transmissible than the Delta variant of the SARS-CoV-2 virus, and reduces vaccine efficacy| (File photo)

New Delhi: The World Health Organization (WHO) said Sunday that the Omicron coronavirus variant is more transmissible than the Delta variant of the SARS-CoV-2 virus, and reduces vaccine efficacy. However, Omicron causes less severe symptoms as per early data, the health agency noted. 

The Delta variant is the dominant strain in most nations and was first identified in India earlier this year. Most of the coronavirus infections worldwide can be attributed to the Delta variant.

Following the discovery of the Omicron variant in South Africa, countries around the world started imposing travel bans on South African countries and reintroduced domestic restrictions to slow the spread of the newly mutated strain.

As of December 9, Omicron had spread to 63 countries, according to the WHO. In South Africa and Britain, faster transmission of the Omicron variant has been observed. The Delta variant is the less prevalent in South Africa, and is the dominant strain in Britain. 

The WHO, however, noted that a lack of data meant it could not say if Omicron's rate of transmission is higher because it is less prone to immune responses, due to higher transmissibility, or a combination of both.

The WHO said in a technical brief that early evidence suggests Omicron causes "a reduction in vaccine efficacy against infection and transmission," the AFP report stated. 

The health agency added that it is likely that Omicron will outpace the Delta variant where community transmission occurs.

Though Omicron has caused "mild" illness or asymptomatic infections so far, the data is insufficient to establish the clinical severity of the variant, as per WHO. 

Pfizer/BioNTech said last week that three doses of the Covid-19 vaccines manufactured by these companies are still effective against Omicron.

Britain and France are among the countries that have sufficient vaccine supplies and have encouraged their populations to receive a third "booster" dose to fight the Omicron variant.