NEW DELHI -- Around 40 cases of the 'delta plus' strain -- a mutated version of the highly contagious delta variant that drove the much of the devastating second wave of the COVID-19 pandemic in India -- have been detected in the country, the health ministry said Wednesday, amid concerns over a possible resurgence of infections in the South Asian nation.
Three Indian states -- Maharashtra, Kerala and Madhya Pradesh, where the delta plus variant, also known as AY.1, has been observed sporadically -- have been advised to step up surveillance and undertake appropriate public health measures, the ministry said.
The statement comes as India's daily cases have fallen sharply, to less than 100,000 in recent weeks from a high of over 400,000 per day in early May. On Wednesday, India recorded 50,848 new infections and 1,358 deaths, bringing the total number of cases to over 30 million, with 390,660 fatalities. India is the only country other than U.S. with a total caseload of more than 30 million.
The health ministry said the delta variant and all delta sublineages, including delta plus, are classified as variants of concern, although the properties of AY.1 are still being investigated.
"Currently, the variant frequency of AY.1 is low in India," it said, adding that cases of AY.1 have been mostly reported in nine countries in Europe, Asia and North America. Health Secretary Rajesh Bhushan said on Tuesday those nine countries are the U.S., the U.K., Portugal, Switzerland, Japan, Poland, Nepal, China and Russia. In India, he said, the problem of the delta plus currently looks "fairly small in terms of numbers, but we would not want this to assume significant proportions."
Around 40 cases have been identified in India so far and there is no significant increase in prevalence, the ministry statement said Wednesday. "As of 18th June, 205 sequences of AY.1 lineage [were] detected worldwide, with [the] USA and [the] U.K. having over half the known cases," it said, pointing out that AY.1 was first reported in a Public Health England bulletin dated June 11.
It added that the delta plus variant has the K417N mutation, which has been of interest as it is present in the Beta variant, first documented in South Africa, which was reported to have immune evasion properties.
Citing INSACOG, an Indian consortium of 28 labs established by the federal government to carry out genome sequencing of the virus causing the COVID pandemic, an earlier statement from the ministry said the delta plus variant's characteristics are increased transmissibility, stronger binding to receptors of lung cells, and potential reduction in monoclonal antibody response.
Its latest statement added that the role of AY.1 "in immune escape, disease severity or increased transmissibility etc. is under continued surveillance."
Maharashtra's state health department reportedly said recently that the delta plus variant could trigger a third wave of the pandemic.
Acknowledging that the emergence of delta plus cases in some Indian states is a concern, and that the variant could spread to other parts of the country, Rajinder K. Dhamija, head of the neurology department at Lady Hardinge Medical College and a former WHO fellow at the National Institute of Epidemiology, said this development has to be watched for the next few weeks.
"As of now, we don't know whether the COVID-19 vaccine would be effective against this variant or not," he told Nikkei Asia, adding that people should wear double face masks in public places to protect themselves. "Double masking is even more effective than a vaccine," Dhamija said.