The good news is that the vaccines work against a new virus strain circulating in India that has spread to several other countries.

The bad news is it won’t be only the new version of the pathogen to emerge from an outbreak of this scale, underscoring the urgency of mapping other possible variants that may be currently racing through India’s tightly packed population of 1.4 billion people.

As infections surge by more than 300,000 cases for 14 straight days, pushing India’s tally past 20 million, the country’s limited ability to track new mutations emerging from its outbreak is a growing concern for scientists.