India has reported a gradual decline of Covid-19 cases after reporting a high number of daily new cases in September and October 2020. The general impression from rising cases in September was that the situation in India would get worse in the coming months. The seasonal effect of colder weather combined with a winding down of lockdown measures was supposed to trigger a surge in cases. But the cases have gradually declined, and the reason for this has confounded experts.
The decline in cases in India is puzzling but seems to be real as the testing positivity rate has also declined to around 2%, as shown in Figure 1. Hospitalisations and mortality are also lower than in the first wave, which lends support to the argument that cases are indeed declining in India.
There are multiple hypotheses but no concrete evidence of why India is experiencing a low number of daily new cases. Non-pharmacological intervention (NPI) could provide some of the explanation. Certainly, a mask mandate and social distancing could have a positive effect on reducing the number of daily cases. According to Genevie Fernandes, a public health researcher with the Global Health Governance Programme at the University of Edinburgh, India’s testing capacity has increased and there is greater awareness for people to follow NPIs. But on the other hand, India is a densely populated country with around 1,200 people per square mile. Social distancing is extremely difficult to follow under such circumstances. There is also speculation on favourable environmental factors; according to Daksha Shah, an epidemiologist and deputy executive health officer in India, the hot and humid climate of India is favourable in controlling the spread of the virus. But this is questionable, as other countries such as Brazil and Mexico did not seem to benefit with the similar weather. There are also suggestions that a proportion of the Indian population has innate immunity from exposure to related infections in their lives, which boost their immune response to the novel coronavirus. However, India has one distinct advantage over the European countries, which is its relatively younger population; this suggests that outcomes will be more favourable for positive cases in Indians.
In India, the current rate of new cases is 10 new cases per one million population, in marked contrast to the US rate of 370 cases per one million population. This is astounding as, until recently, experts were predicting that India will overtake the US as the most heavily affected country in the world. However, India should not be complacent as the viral mutations in South Africa, Brazil, and the UK are causing alarm around the world. These mutations allow the virus to be more contagious and may cause vaccines to be less effective. India should remain vigilant and continue to implement proactive public health measures to prevent the spread of these new variants in their country.
Figure 1: Covid-19 Daily New Cases and Testing Positivity Rate, India, 1 April 2020–3 February 2021.