India had entered the endemic phase of Covid-19 from June end/early July, and for the last 22 weeks the reported daily cases have been steadily coming down. As a result, states have started relaxing curbs on gatherings and reopening educational institutions. Also, the pace of vaccination has picked up and as of December 8 this year, 58% of the entire population has been administered one dose and 35% has been double jabbed.
It looked like we were out of the woods when Omicron, with a large number of mutations (more than 30) in the spike protein gene and three times the infective potential of Delta variant, was reported from Gauteng province of South Africa, the epicentre of this outbreak. The seven-day rolling average of the number of new cases in South Africa, which had decreased to less than 300, rose to 4,840 in just two weeks. And on December 2, in a single day, the number of infections went up exponentially to 11,535. In Tshwane district in South Africa, the number of admissions of children under age two increased dramatically to greater than 10% (52 out of 452) of all Covid admissions. The WHO quickly responded by labelling it a variant of concern and at least 57 nations have reported Omicron’s presence—mostly in travellers from highly affected countries and to a lesser extent, by community transmission.
There are two features of this outbreak that are alarming. One, a large number of people who were previously afflicted with Covid or completed two-dose vaccination tested positive for the variant, indicating that previous infections and jabs do not fully protect against Omicron. And two, a spate of admissions due to these infections, presumably with the variant, have been reported in South African children.
The major solace is that almost all the reported infections have been mild to moderate with throat irritation and extreme fatigue, and there have been only very few cases of severe disease and death. But we need to wait for the next four weeks to see if hospitalisation from severe disease increases as there is a lag time between infection and serious illness requiring in-patient treatment.
India has already reported 25 confirmed cases of infection with Omicron, mostly in international travellers and one in a medical professional without any travel history. The latter is an instance of community transmission and suggests that the variant is circulating—largely undetected—in India. The observation that many of the travellers into India from January 1 are allegedly not traceable suggests that we could potentially have infected subjects moving around freely. This possibly portends a spate of cases and further community transmission of the variant in the coming weeks.
There are three important steps that need to be immediately pursued in order to tackle this epidemiological emergency. One, educating the public about social vaccine and reinforcing the importance of practicing this effective measure for personal protection. Two, a quick policy decision on administration of a booster dose for the elderly and the vulnerable, and its effective implementation. Three, a fast policy response on Covid vaccination for kids—this requires fast-tracking the extension of emergency use authorisation of vaccines (recommended by the expert panel) found suitable for children.
It is likely that we will see an outbreak with this new variant in India. But judging by the proportion of the population already infected by the Delta variant during the massive wave earlier this year and the number of people who have received at least one dose of the vaccine, even if the documented infections increase, mortality and hospitalisation due to serious disease may be lower than that during the second wave or even the first. However, children under 18 are not yet eligible for vaccination in India. Therefore, there is an urgent need to increase the number of paediatric beds for isolating and treating sick children all over the country, particularly in crowded metros.
There is one more possibility. In live attenuated vaccine production, the cultured virus goes through repeated passages in the laboratory and changes its properties by reducing its virulence; it thereby becomes a live attenuated virus, suitable for use as a vaccine. The coronavirus may have spontaneously become attenuated by prolonged replication in an immunocompromised human subject when the world was in the grip of this pandemic. If this is true, the variant, in spite of increased infective potential, may not cause serious disease. On the other hand, spread of the variant per se may have a booster effect on immunity against future infections by this virus or its close relatives without causing serious disease. In short, the Omicron infection may eventually behave like the common cold virus—the much-awaited attenuated virus in perpetual endemicity.
Dr M S Seshadri
Medical Director, Thirumalai Mission Hospital, Ranipet
Dr T Jacob John
Former Professor of Clinical Virology, CMC, Vellore
(mandalam.seshadri@gmail.com, tjacobjohn@yahoo.co.in)