The country of 1.35 billion celebrated Durga Puja in October and Diwali this month, during which millions of people shopped, travelled and met family, mostly without masks. Mask-wearing is nearly non-existent outside the big cities.
"Even after Diwali, we are not seeing a surge," said M.D. Gupte, a former director of the state-run National Institute of Epidemiology, attributing it mainly to the presence of antibodies in a huge majority of Indians through natural infection.
"I think we are much safer now," Gupte added, Reuters reported.
Government surveys have estimated that nearly 70% of Indians had been naturally infected by July, following a record rise in infections and deaths in April and May.
So far, 81% of India's 944 million adults have received at least one dose of vaccine and 43% have had two doses. Vaccination for people under 18 has not yet begun.
India has reported a total of 34.5 million COVID-19 cases, second only to the tally in the United States. India's COVID deaths rose by 236 in the past 24 hours to 466,147.
Daily testing has also fallen, dipping below 1 million on Monday compared with a capacity of more than 2 million.