A study on the spread of Covid-19 in 84 countries by a team of researchers at the Massachusetts Institute of Technology (MIT) concludes that India could top the rank of daily-cases by Winter 2021.
In a preprint paper, MIT professors - Hazhir Rahmandad and John Sterman, and Tse Yang Lim made the observations. The research adds that India's daily case count by the end of winter 2021 would be highest at 2.87 lakh infections per day followed by US, South Africa, Iran, Indonesia, the UK, Nigeria, Turkey, France, and Germany.
India ranked number third on total cases has been adding an average of 21,000 fresh cases daily.
The research is however limited to certain assumptions on testing, behavioural, and policy responses. The research team also observed that the statements should be interpreted as indicators of potential risk and not precise predictions of future cases. "We explore a few projections out to spring 2021 that exclude vaccine and treatment availability," said the researchers.
The researchers considered projections under three scenarios, namely:
1. Using current country-specific testing rates and response functions moving forward,
2. If enhanced testing -- of 0.1 per cent a day -- is adopted on July 1.
3. If sensitivity of contact rate to perceived risk is set to 8, leaving testing at current levels.
The first two scenarios project a very large burden of new cases in the fall 2020, with hundreds of millions of cases concentrated in a few countries estimated to have insufficient responses given perceived risks, primarily India, but also Bangladesh, Pakistan, and the US.
"Our model simulates the progression and spread of COVID-19, including how people interact, how many get sick, how many get tested, how many are hospitalized, how many die -- and how people change their behaviour in response to the risk they perceive," Rahmandad, one of the researchers explains.
"We then use a wide range of data to estimate the parameters of the model -- say, what fraction of infections are asymptomatic, and how contagious the virus is -- to give the best match to the real world data," they said.
The model revealed several important insights. Most fundamentally, the magnitude of the epidemic is widely underreported, the researchers said. They estimate that cases and deaths through June 18 are, respectively, 11.8 and 1.48 times higher than official reports across the 84 nations considered.
"While actual cases are far greater than official reports suggest, the majority of people remain susceptible. Waiting for herd immunity is not a viable path out of the current pandemic," Rahmandad said.