India / Severity anticipated to be low: Govt on whether Omicron variant will cause 3rd wave

New Delhi: The Ministry of Health and Family Welfare on Friday published answers to a set of frequently asked questions (FAQs) on the Omicron variant of coronavirus in the wake of mounting concerns over its high number of mutations.

The variant was first detected in November in South Africa and has since spread to dozens of countries including India. Two people in Karnataka have tested positive for variant so far.

What is Omicron and what makes it a variant of concern (VoC)?

Omicron is a new variant of SARS-CoV-2 and was first reported from South Africa on 24th November. The variant shows a large number of mutations, including over 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 positive cases in South Africa, the World Health Organization (WHO) has declared Omicron as a Variant of Concern (VoC).

Omicron’s official name is B.1.1.529, which conveys the evolutionary history of the variant.

Can current diagnostics methods detect Omicron?

The most accepted and commonly used diagnostic method for SARS-CoV- 2 Variant is RT-PCR. This method detects specific genes in the virus, such as Spike (S), Enveloped (E) and Nucleocapsid (N) etc to confirm the presence of virus. However, in the case of Omicron, as the S gene is heavily mutated, some of the primers may lead to results indicating absence of the S gene. This particular S gene drop out along with the detection of other viral genes could be used as a diagnostic feature of Omicron. However, for final confirmation of the omicron variant genomic sequencing is required.

How concerned should we be?

WHO declares a variant as a VoC for several reasons. Firstly, a rise in transmissibility or detrimental change in Covid epidemiology. Secondly, an increase in virulence or change in clinical disease presentation. Lastly, a decrease in effectiveness of public health and social measures or available diagnostics, vaccines and 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 epidemiology, such as increased reinfections. The definitive evidence for increased remission and immune evasion is awaited.

What precautions should we take?

The precautions and steps to be taken remain the same as before. It is essential to mask yourself properly, take both doses of vaccines (if not yet vaccinated), maintain social distancing and maintain good ventilation as far as possible.

Will there be a third wave?

Omicron cases are increasingly being reported from countries outside of South Africa. However, the scale and magnitude of rise in cases and most importantly the severity of disease that will be caused is still not clear. Further, given the fast pace of vaccination in India and high exposure to the delta variant, the severity of the disease is anticipated to be low. However, scientific evidence is still evolving.

Will the existing vaccines work against Omicron?

While there is no evidence to suggest that existing vaccines do not work on Omicron, some of the mutations reported on the spike gene may decrease the efficacy of existing vaccines. However, vaccine protection is also by antibodies as well as by cellular immunity, which is expected to be relatively better preserved. Therefore, vaccines are expected to still offer protection against severe disease, and vaccination with the available vaccines is crucial.

How is India responding?

The Indian government is monitoring the situation closely and is issuing suitable guidelines from time to time. Meanwhile, the scientific and medical community is geared up for developing and deploying diagnostics, carrying out genomic surveillance, generating evidence about viral and epidemiologic characteristics, and development of therapeutics.

Why do variants occur?

Variants are a normal part of evolution and as long as the virus is able to infect, replicate and transmit, it will continue to evolve. Further, not all variants are dangerous and most often than not, we don’t notice them. Only when they are more infectious, or can reinfect people they gain prominence. The most important step to avoid generation of variants is to reduce the number of infections.