Indian Covid-19 Puzzle?

India has a population of 1.4 billion people and, in September 2020, had 100,000 coronvirus cases each day. Everyone predicted, that the country would overtake the US and come to have the most Covid-19 cases. Strangely, by the end of January 2021, India's Health Ministry reported a mere 9,100 new cases per day and declining numbers in Intensive Care Units. The decline occurred before the onset of mass vaccination and was not a consequence of reduced levels of testing (https://www.nprillinois.org/post/mystery-indias-plummeting-covid-19-cases#stream/0). Some possible reasons for the declines in infection rates have been tentatively floated. Firstly, although Indians are generally poor about following rules, mask wearing has been maximised, by police enforcement with fines (and provison of a free mask). In addition, the ring tone on all telepone calls (land lines and mobiles), has been replaced by Covid safety messages from the government or a Bollywood star. Secondly, warm and wet climates (like India) may result in virus-containing aerosols falling to the ground more quickly than in cold, dry air. Thirdly, the rates of viral tranmission appear very low in aparts of India. In the Punjab, for example, 76% of patients infected nobody else. Fourthly, as Indians, are exposed to many potential disease agents, they might have particularly robust immune systems. Fifthly, age is an important risk factor for Covid-19 and only 6% of Indians are older than 65. Indeed, 50% of Indian's population is under 25 (they are a low risk category). Sixthly, blood antibody measurements suggest a majority of Indians, in some areas, have been exposed to the coronavirus. Seventhly, it has been suggested that an especially mild variant of the Sars-CoV-2 virus might have arisen in India. The truth is that nobody knows why this unusual pattern has been seen in India. There are some other strange observations. It was feared that crowded Hindu festivals (Diwali and Durga Puja) and massed demonstrations by farmers might be 'super spreader' events but they all passed without bumping up infections. Another oddity is, that people in the UK from Indian or Pakistani heritages, appear more vulnerable to Covid-19 than some other ethnic groups. This suggests that life-style is more important than genes. Study of the Indian phenomenon may help us to better understand the factors that influence the transmission of Covid-19.