New Delhi: While, there is no evidence to suggest that existing vaccines do not work on Omicron, some of the mutations reported on Spike gene may decrease the efficacy of existing vaccines, says the government.
As part of Frequently Asked Questions (FAQs) released by the government, "Vaccine protection is also by antibodies as well as by cellular immunity, which is expected to be relatively better preserved. Hence vaccines are expected to still offer protection against severe disease and, vaccination with the available vaccines is crucial."
The precautions and steps to be taken remain same as before, says government, adding, "It is essential to mask yourself properly, take both doses of vaccines (if not yet vaccinated), maintain social distancing and maintain good ventilation to the maximum possible."
Omicron is a new variant of SARS-CoV-2 that has recently been reported from South Africa on November 24, called as B.1.1.529 or Omicron (based on Greek alphabets like alpha, beta, delta etc). This variant has shown a very large number of mutations, especially more than 30 on the viral spike protein, which is the key target of the immune response.
Given the collection of mutations in Omicron, which earlier individually have been associated with increased infectivity and/or immune evasion, and the sudden rise in number of positive cases in South Africa, World Health Organization has declared Omicron as a Variant of Concern (VoC).
The WHO declares a variant as a VoC after assessment when there is increase in transmissibility or detrimental change in COVID-19 epidemiology; OR increase in virulence or change in clinical disease presentation; OR decrease in effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics.
It is important to highlight that Omicron has been declared VoC based on the observed mutations, their predicted features of increased transmission and immune evasion, and preliminary evidence of detrimental change in COVID-19 epidemiology, such as increased reinfections. The definitive evidence for increased remission and immune evasion is awaited.