The science of the second wave
Information on the new variant, B.1.617, can impact containment and vaccination strategy
India has now taken the global spotlight as the worst hotspot for Covid-19. The surge has triggered a key question. Is a variant of SarsCov-2 to blame? The question stems from the experiences of several other countries. The B.1.1.7 variant, first found in the United Kingdom, appears to trigger an entirely new wave of infections when it takes hold — this happened with England, then the rest of the island, followed by parts of Europe and the United States (US). Having gained an ability to spread more readily, B.1.1.7 has often required nothing less than a lockdown to slow it down.
Now, a new variant has been spotted in India – B.1.617. Where it was found and how frequently it has been spotted are worrying indicators for what it may be able to do. It arose in Maharashtra, which began bucking the national trend of flat case trajectories almost a fortnight before infections began to rise elsewhere. The state was eventually forced into a lockdown. The variant is now popping up in other countries, where calls are growing to ban flights from India. Western scientists spotted a tell-tale trend in genome sequences submitted from India to the global GISAID repository — the variant was popping up more frequently in samples. These patterns reinforce the fear that B.1.617 may be fuelling India’s wave, although there is also a strong possibility the B.1.1.7 may have also taken hold. On March 24, health ministry officials said B.1.1.7 was found in large numbers in community samples in at least one state, Punjab.
The answers to all these questions lie in better genomic surveillance. Till April 1, India sequenced only 0.67% of new cases recorded this year. The first of the clues from the sequences came not from Indian scientists but those from Scripps Research in US who spotted the growing footprint of B.1.617. Almost a month since the March 24 press conference by the health ministry, there is little detail of when and where these were discovered – data that could unlock the mystery of India’s second wave. If variants are a major factor, it has farreaching consequences for how the country approaches containment (cities may need tougher curbs sooner) as well as its vaccination strategy (the country may require doses that are more resilient to mutations). It is about time these questions are answered, beginning with information about when and where the variant samples came from.