India’s effective reproduction value (R) for COVID-19 – which shows how quickly the virus is spreading – has gone above 1.0 for the first time since January, according to a researcher from Chennai’s Institute of Mathematical Sciences.
The last time the R-value was above 1 was between January 16-22, when it was 1.28.
In an email interview with news agency PTI, the researcher – Sitabhra Sinha – said India’s R-value was 1.07 for the week between April 12-18. From April 5-11, it was 0.93, he said, adding that the R-value is rising not only because of Delhi but also due to Haryana and Uttar Pradesh.
“The total cases in India are indeed increasing exponentially. Of course, this being a very large country, this national rise is primarily being driven by a few regions – one cluster in the north (Delhi, Haryana, UP) and the other in the south (Karnataka),” Sinha said.
“It is interesting that the major cities of Mumbai, Chennai and Bengaluru also have R above 1, suggesting that urban areas may be showing an increasing number of cases even though at the level of the entire state such an increase may not yet be apparent,” he noted.
What is R-value?
The R-value or R0 (pronounced ‘R-naught’) is the rate of reproduction of COVID-19. It is used by the researchers to track COVID-19 and predict how quickly it may spread in a given geographical area.
An R-value of over 1 indicates that the number of active cases has increased. R should be contained below 1 to control the pandemic. An R number lower than 1 indicates that the disease will stop spreading as there aren’t enough people being infected to sustain the outbreak.
What’s the R-value in different states?
According to Sinha, the R-value is above 2 in Delhi and Uttar Pradesh (2.12 each), while it is 1.70 for Haryana, 1.18 for Chennai, 1.13 for Mumbai, and 1.04 for Karnataka and Bangalore. Maharashtra and Kerala, meanwhile, have an R-value of 0.88 and 0.72 respectively.
“The value for India we have estimated at the present is roughly what the R-value was (1.08) between February 14-March 11 last year – i.e., just before the onset of the second wave in India when it rose to 1.37 on March 9-April 21, 2021, before decreasing to 1.10 (April 29-May 7) and finally decaying to values below 1 by May 9 (R: 0.98),” Sinha explained to PTI.
“At the height of the Omicron wave R had risen to its maximum value so far (for India) of 2.98 (December 30, 2021-Jan 10, 2022). Contrast this with the next highest value of R during the beginning of the first wave, 2.51 (March 14-April 5, 2020),” he added.
Will it lead to a fourth wave?
Although India’s R-value is rising due to a spike in COVID-19 cases, some scientists believe that it would not lead to a fourth wave of the pandemic. Speaking to news agency ANI, former Chief Scientist of the Indian Council of Medical Research (ICMR) Dr R Gangakhedkar said the “chances of the fourth wave can’t be seen as of now” as no new variant has been reported so far.
He said people have also become socially active due to the reopening of schools and colleges, leading to a spike in COVID-19 cases. However, he warned that people must continue wearing face masks to avoid a surge in cases.
“The withdrawal of the use of masks is also the reason for the surge in cases. It is also true that some of us still have misunderstood the mandatory use of masks, which has been withdrawn. Some of us may be presuming that there is no fear of acquiring any infection so I can move freely and they have stopped using the mask and therefore, they also get infected if they come in contact with somebody who’s infected as of now,” he told ANI.
“The last thing which we have to remember is when we talk in terms of these newer variants, which are coming BA.4, BA.5 from South Africa, and the recombinant variants that are coming, there are two factors which will have proven that all these variants continue to belong to Omicron family. So whatever protection that natural infection has given to us is likely to persist for a longer period. It could be about six to nine months’ time. And it is also important to remember at recombinant variants, by and large, do not live longer to spread the infection because recombination events are an accident. And that’s not the natural evolution of the virus. So we need not worry in terms of the emergence of the fourth wave,” he added.
