India desperate for oxygen amid record COVID surge

Normalizing business activities without strict observance of protocols, inadequate self-quarantine measures due to family reasons, over-confidence in large-scale vaccinations, and changing behavior because of the false belief that the pandemic is under control, could also be to blame, Singh said.

Ruklanthi de Alwis, senior research fellow at SingHealth Duke-NUS in Singapore, said lax preventive measures in tandem with nationwide election rallies and popular festivals in India are among the reasons for the rise in infections. She also singled out the emergence of a highly infectious new SARS-CoV-2 variant in the country.

In Maharashtra, India's richest state and home to its financial hub Mumbai, a "double mutant" strain named B.1.617 was detected in 220 of 361 COVID samples collected from January to March, according to the National Institute of Virology. The variant has reportedly been observed in more than 20 countries and regions, including Hong Kong, although scientists have yet to determine its impact.

Singh said the new strain of the virus is believed to be mutating rapidly and this is becoming difficult to prevent, as it appears to be more asymptomatic than others.

"The biggest challenge is to contain the virus in order to save lives," he said.

The Indian government has adopted safety and preventive measures for religious gatherings. Further restrictions and localized lockdowns are likely to be imposed in a number of states, and new guidelines may be issued for electoral campaigns and election-related activities.

Other action taken includes night curfews, selective lockdowns, setting up local containment areas, revamped public health measures, regulations introduced for private hospitals treating patients, and enforced strict observance of COVID-19 protocols and guidelines at public places, organizations and institutions.

"However, I don't think the government will opt for a full-scale lockdown," Singh said.

Anup Kumar Sinha, an economist, said, "March 2020 and April 2021 are different times. In March 2020, we were virtually defenseless against the virus, and a lockdown was perhaps the only option, but now with the vaccine coming in, we are in a somewhat better position." He added that the second wave would deal another cruel blow to migrant laborers.

Modi has urged Indian citizens to be vaccinated and exercise caution.

Samiran Panda, head of the epidemiology and communicable diseases division at the Indian Council of Medical Research, said the government has taken a series of measures, including adding people age 18 and older to the nation's inoculation campaign, which takes effect on Saturday.

The production and supply of vaccines can be accelerated, as the US has spoken of removing export bans on vaccine materials, Panda added.

However, a senior doctor at the All India Institute of Medical Sciences said a supply shortage, which is already affecting the vaccination drive, could slow it further.

The Health Ministry said that as of Sunday, 140 million vaccine doses had been administered in India.