In the backdrop of the surge in Covid-19 cases in Brazil, Japan, the US and Republic of Korea and in particular, the situation unfolding in China, India is on full alert and not taking chances. The Union health minister reviewed the situation on Wednesday and chalked out steps that aim to prevent another spike in India. To underscore the government’s seriousness, all those who attended wore face masks though it is no more mandated. The government has reaffirmed that “Covid is not over yet”. It has now advised people to mask up in crowded places and strengthen surveillance, including genomic surveillance.
During the week of 5-11 December, the number of new weekly cases increased by two per cent (as compared to the previous week) while weekly deaths increased by over 10 per cent. Cases declined in the South East Asia Region (that includes India) by a third (33 per cent). The Western Pacific Region (that includes China) marked a three per cent increase and the Region of the Americas recorded a 27 per cent rise. At the country level, the US registered a 50 per cent weekly increase and Japan and the Republic of Korea 13 per cent each.
The WHO cautions that the current numbers are to be interpreted with the caveat that many countries have changed testing strategies which meant lower numbers being tested. Consequently, Covid-19 prevalence surveys have often confirmed that the notified Covid-19 cases are under-estimates.
The BA.5 Omicron subvariant continues to be the dominant strain with the WHO reporting a prevalence of 73.7 per cent in the week of 14 to 20 November 2022. It accounts for much of the cases in the US. This subvariant spreads rapidly on account of its immune evasive property, causing infections despite previous Covid infections and vaccination. The BA.2 descendent lineages follow with a global weekly prevalence of 10.4 per cent. At present, BA.2.75 and XBB subvariants have emerged and demonstrated increased prevalence in some countries in South East Asia and Western Pacific regions.
The BF.7 subvariant seems to be responsible for the recent surge in Beijing and possibly other cities in China too. BF.7, or more correctly BA.5.2.1.7, is a sub-lineage of the omicron variant BA.5. BF.7 and is remarkable in that it seems to have an exceptional capacity to infect those who have had a previous Covid infection, or been vaccinated or both. Omicron has an average R0 of 5.08, meaning that one infected person will transmit the virus to about five more persons. In contrast, BF.7 is reported to have an R0 value of 10 to 18.6.
What could be a source of worry is the results of a study in the US that found that BF.7 was resistant to neutralisation in samples from triple-vaccinated healthcare workers, as well as patients infected during the Omicron BA.1 and BA.5 waves. This resistance is explained by the R346T mutation. The combination of higher transmissibility and a higher proportion of asymptomatic carriers explains the difficulties that Chinese cities are facing in controlling the current wave. This is against the backdrop of a relatively low natural infection in China.
BF.7 has been detected in the US, UK and in several countries in Europe including Belgium, Germany, France and Denmark. BF.7 was first detected in India by the Gujarat Biotechnology Research Centre (GBRC), Gandhinagar. So far two cases have been detected in Gujarat and one in Odisha.
The WHO opines that the extent to which the enhanced immune escape properties of the newly emergent Omicron descendent variants can lead to new waves is likely to depend on the “regional immune landscape, the size and timing of previous Omicron waves, and the Covid-19 vaccination coverage”. For India, these conditions seem to be favourable at this point in time. The lack of widespread uptake of booster doses remains a matter of concern for those individuals who may be vulnerable on account of age or other comorbidities. While some have called for travel-related restrictions, these are of little practical and epidemiological relevance.
As the central government continues to lead the Covid-19 response at the national level, district and municipal level surveillance shall be crucial in picking up the red flags. This makes preparedness and operational readiness at the local levels critical in the next few weeks.
The current phase of the pandemic has come at a time when India has taken up the G20 presidency. As we know, health systems are going through the processes of recovery, reformation, and rejuvenation and all countries are recalibrating to build resilience into their health services to be able to effectively and respond efficiently to health emergencies. Despite immense challenges, India has responded reasonably well through the last three years including in building up capacities of medical countermeasures — through diagnostics, pharmaceuticals and vaccines — as well as digital innovations. Several G20 members are witnessing this surge. This could be the India moment to demonstrate both effective responses as well as establish greater collaboration among member states through a coordinated and shared response framework.
The writer is Professor at the Centre of Social Medicine and Community Health, JNU
