India probably has an innate, natural defence against the deadly coronavirus (COVID-19) after all, if one goes by the latest theory that some experts have propounded.This could sound highly anomalous at a time when India's worst coronavirus fears are seemingly coming true. Going by the Health ministry's update that puts the number of infected in India at 73 now, it appears that after infecting nearly 1,20,000 and killing over 4,200 worldwide, the virus has now begun giving India the full play.There is a spike in the number of the infected, and apprehensions over hidden, hitherto-undetected cases are rising. In other words, fear now has a new name.But there are experts who see it differently. India is largely safe, and this relative safety lies in its weather which acts as a defence against the virus, says K K Aggarwal, president, Heart Care Foundation of India.That could be exactly the reason why Ebola, yellow fever, SARS and MERS — which took a high global toll over the past one decade — had negligible impact on India, Aggarwal told ToI.After ravaging the countries that have more agreeable climatic conditions, viruses — no matter however deadly — lose their killer edge once they encounter India's relatively high temperature and humidity that make life difficult for them, he added.Aggarwal, also a former president of the Indian Medical Association, traces the origin and spread of the epidemic thus: Viruses prefer lower temperatures, which is why they have spread speedily in cooler and less humid areas like Japan and South Korea. In India's case, an outright outbreak seems unlikely because of the heat and humidity, he says.Souren Panja, Head, Critical Care, RTIICS concurs with Aggarwal. The typical Indian weather is certainly a deterrent, he believes. According to him, "The geographical spread of nCoV suggests that it has so far been restricted to cooler climates."According to Arindam Biswas, and internal medicine consultant, three factors determine a virus' spread — the "agent or the virus itself, the host and the environment". While the agent and the host are present everywhere, India doesn't give the virus an ideal weather condition, he thinks.So, will the scorching Indian summer that is just a few fortnights away really stem the outbreak? Fingers are still crossed, but speculations are gaining ground.The experts, however, also have a grim warning — they are not ruling out the possibility of a 'silent transmission' of coronavirus in India . Which means, the transmission of the disease could be occurring in undetected ways, and may lead to a disaster at some point.While they all agree that Modi govt has done a fine job of containing the threat so far, they also fear that the typically high incidence of pneumonia in the country may be potentially masking the transmission of coronavirus, which could be dangerous when cases eventually break out.This has an ominous echo of the warning issued a few days ago by Harvard public health professor Kasisomayajula Viswanath: "Right now they are able to control it, and monitor it, and treat it effectively. But if it is spreading along with other contagious diseases that are already here, then it becomes a matter of considerable concern."Will the heat-and-humidity theory still hold water when the last case file has been closed and the last victim buried? As of now, despite these expertspeaks, there is insufficient data to come to a conclusion.According to a large section of experts, India's risks of catching the virus are disproportionately high because of its high population density, creaky healthcare mechanism and high internal migration.India's case could be more worrisome than most other countries in the event of an outbreak. The first reason is population density: each square kilometre in India accounts for as many as 420 people, way higher than in most countries of the world.The second factor is the exceptionally high rate of internal migration: as per the last census, 45 crore people migrated inside India in such of jobs and other opportunities. This could turn out to be a nightmare in case an outbreak occurs, particularly because Hubei-like lockdowns in India are next to unthinkable.The third reason is our overburdened, creaky, rickety public health regime — about which the less said, the better. If an outbreak occurs, India's public health system — in all likelihood — will be overwhelmed in no time. Add to this India's generally pathetic hygiene habits, and you have a perfect recipe for nightmare.The paramount fear now is that the situation could degenerate very rapidly if 'super spreader' cases emerge. Super spreaders (human carriers) are infected people who transmit the disease to a large number of people in a community — like the one suspected in China's first wave of cases.