Despite the vaccine rollout, India is grappling with a devastating second wave of COVID-19 cases. Recently, one-third of the global new coronavirus cases were reported in India, with 294,000 new cases and 2000 deaths in the country yesterday.
With concerns mounting over a potential mutant variant of the virus found in samples collected in India, the spike in cases has led the UK, Hong Kong and New Zealand to ban inbound flights from the country.
What caused the second wave?
While there is no clear-cut definition of what constitutes a wave, it implies a significant and/or exponential rise in cases, reaching a defined peak and then dropping. On a graph, this would be a parabola, in which each parabola would signify a different wave.
Waves of infection are most often caused by human behaviour, and largely depend on individual and government responses to an epidemic.
Physical distancing measures are an effective disease management strategy, but are significantly harder to control in densely populated areas, such as most Indian cities. Close proximity creates an environment where disease can easily spread as people share air, speak, cough or sneeze near each other.
After COVID-19 restrictions were relaxed in early 2021, events like state elections and pilgrimages for the Hindu religious festival Kumbh Mela meant that people were not only congregating in crowds, but moving from place to place more frequently, quickening the virus’s spread.
Potential new variants with higher transmission rates could also hasten the spread of the virus, compounding the problem.
Why is this so concerning?
Although reportedly only 1% of cases of COVID-19 in India lead to death (currently 183,570 recorded deaths in total compared to 13 million cases), this may not necessarily reflect the situation going forwards, for a number of reasons.
Firstly, reporting isn’t always reflective of the actual death toll, as there may be deaths going unreported. For example, some deaths of people with COVID-19 in the southern state of Kerala may have been erroneously attributed to underlying causes.
Secondly, limited medical resources mean hospitals will not be able to cope with growing volumes of hospitalised patients and the added pressure on beds and ventilators.
Thirdly, there is potential that vaccination will not be effective against new and emerging variants.
What is being done about it?
This second wave led to a one-week lockdown in New Delhi, amid concerns that hospitals will run out of equipment and resources.
Since death rates are higher in hospitals with limited access to healthcare and medical resources, lockdowns and social distancing are methods designed to “flatten the curve’” before hospitalisation reaches crisis point.
India is currently rolling out two vaccines, AstraZeneca and Bharat Biotech’s Covaxin, but the AstraZeneca vaccine has already been shown to have poor efficacy against the B.1.351 variant first identified in South Africa.
As of 20 April, over 127 million vaccine doses have been administered to health care workers and people above 45, which is only a small percentage of the population of 1.3 billion. More than 109 million people have received at least one dose, and 17 million have been fully vaccinated. The country claims to have vaccinated 100 million people in 85 days, the fastest country to do so to date.
India’s current vaccine targets are aimed at innoculating 250 million people by July, but vaccine shortages could be a major hurdle to reaching that goal.
While new variants are concerning, if fewer people are able to be infected in the first place then there is less opportunity for a variant to arise, so quick and widespread vaccinations could hopefully abate new cases long term. India has halted export of AstraZeneca vaccines and approved the Sputnik V vaccine in order to reach that goal.
Ultimately, the conclusion of a wave never guarantees that another wave will not occur, but the most effective ways of preventing them in the future are social distancing and mass vaccination.
Dr Deborah Devis is a science journalist at The Royal Institution of Australia.
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