New variant at the door

Dinesh C Sharma

Science Commentator

THE world has gone into a tizzy ever since the discovery of a new variant of the coronavirus last week. The first case of B.1.1.529 was confirmed from a sample collected on November 9 in South Africa at a time when the country was already grappling with a peak caused by the Delta variant. The new variant was reported to the WHO on November 24. The world body convened the ‘Technical Advisory Group on SARS-CoV-2 Virus Evolution’ on November 26. It is an independent group of experts tasked with monitoring the evolution of the virus and assessing its specific mutations and combination of mutations. Based on available evidence and data, such as the presence of a large number of mutations and detection of cases from almost all provinces of South Africa, the group categorised the new variant as a ‘variant of concern’, calling it Omicron. The quick decision of the group triggered global panic, turmoil in stock exchanges and a spate of travel bans and advisories.

Uncertainties connected with Omicron pose a serious challenge for countries, health systems and the public.

The speed with which health agencies reported the detection of a new variant and the WHO committee assessed data and evidence shows the robustness of the system. The new variant came to notice using the commonly used PCR diagnostics test when several labs indicated that they found one of the three target genes missing in the positive samples. It was then confirmed with genome sequencing which revealed mutations on its spike protein. The scientific data was assessed by the WHO expert group which incidentally is chaired by an Indian scientist, Professor Anurag Agrawal, who is director of the New Delhi-based CSIR-Institute of Genomics and Integrative Biology. Though the group considered the overall risk related to Omicron ‘very high’ because of potential of ‘immune escape and higher transmissibility’, it cautioned that its assessment contained ‘considerable uncertainty’.

The uncertainties are many. The first is about transmissibility. Its genetic structure indicates that it can be more transmissible than Delta, but there is no certainty because the number of cases is still very low. The genomic data also suggests that Omicron can potentially escape the immune system, meaning it can infect already vaccinated persons. Here again, there is uncertainty because different vaccines provide immunity in different ways. Some scientists have opined that vaccines based on the inactivated virus may still provide immunity because they trigger a wider immune response than that afforded by mRNA vaccines. These are still intelligent guesses, in the absence of evidence. Studies will have to be conducted with Omicron.

South Africa has detected Omicron first, but it does not mean that it is not already circulating in other countries where it may have remained undetected. The biggest uncertainty is about the disease Omicron can cause. Will it cause milder symptoms that may not warrant hospitalisation and oxygen support? Can Omicron change the course of the pandemic itself? We know a lot about Omicron but there is a lot more that we don’t know about its epidemiology, severity, immune response, antibody neutralisation and so on.

That is why uncertainties connected with Omicron pose a serious challenge for countries, national health systems and the public. The WHO has advised countries to be vigilant and focus on surveillance and genome sequencing to get a better handle of circulating variants, and share the data with the scientific community. They also have to look for clusters of cases, take up studies and field investigations and so on. The agency has not suggested any travel restriction or other such measures as yet, but many countries are already restricting travel to countries from where initial few cases have been reported. The vigil has been hiked at entry points for international travellers, ironically at a time when many countries are opening to such travel. Such restrictions can have a spiralling effect on the economy, specifically sectors like aviation, hospitality and tourism which have been hit hard in the past two years. Because the Delta variant caught India by surprise, we need to be vigilant about any new variant. All steps need to be taken to ensure that the health system is prepared for any potential surge in cases and to see that all essential health services are also maintained. Any harsh measures such as lockdowns and travel bans should be guided by evidence and not taken under panic.

At the individual level, the best way to deal with the uncertainty is to focus on measures that reduce or minimise the risk of Covid-19, like wearing masks, hand hygiene and physical distancing. Other steps like improving the ventilation of indoor spaces and avoiding crowded spaces can also reduce the risk. In the past few months, complacency had set in and people are either not wearing masks or wearing them incorrectly. Large social, religious and political gatherings are being held everywhere with no social distancing. With the upcoming elections in some states, it will be challenging for the election authorities to ensure Covid-appropriate behaviour.

Omicron has also exposed gaps in vaccination, despite the availability of a suite of vaccines. Many countries in Africa are yet to vaccinate their populations, while booster shots are being administered in some rich countries. The virus will continue to circulate, and mutate in the process, in areas with inadequate vaccine coverage. The world is not going to be safe till everyone is protected. Therefore, vaccination in countries and regions with very low coverage should be a global priority. It is the responsibility of the international community to ensure equitable distribution of vaccine doses. Developed countries, in Europe, where anti-vaccine movements are active, should also take proactive measures to counter such opposition. In India, the effort should be to reach the unvaccinated and to fully vaccinate those who have had only the first shot. Omicron is one more reminder that the pandemic is not yet over and has not even taken a pause.