ICMR scientist Dr Samiran Panda says India is still a long way from attaining herd immunity.


New Delhi: Amid the ongoing Covid vaccination drive across the country, the fifth round of serological surveillance conducted in the national capital reveals that Delhi is moving towards attaining herd immunity. Meanwhile, over 8,200 healthcare workers received Covid-19 vaccine shots in Delhi in the second week of the vaccination drive as the city recorded a turnout of more than 77 percent. This is the highest number of people taking the vaccine in a single day ever since the country-wide drive began on 16 January.

The report suggests that more than 50% of those surveyed have developed antibodies against Covid. According to reports, this is the highest seroprevalence found during surveys conducted by the Delhi government since the Covid outbreak. As the number of Covid cases is declining, several experts maintain that a major section of the population might have already got infected and the latest results of the serosurvey also point towards this.

Meanwhile, Dr Samiran Panda, Scientist and Head of Epidemiology and Communicable Diseases Division at Indian Council of Medical Research (ICMR), told The Sunday Guardian that Delhi or other parts of the country are still a long way from attaining herd immunity.

“One needs to look into the urban and rural populations in Delhi as well. Once we split the population data, we will see that the 61% required for herd immunity has still not been infected with Covid in Delhi. Delhi is not India. I can tell you that there is tremendous heterogeneity among the states in India and herd immunity would mean that 70-80% of people get infected with Covid. That is not the case for any state. Even for Delhi, that is not the case, so it is only appropriate to say that India or any state of India for that matter has not reached the stage of herd immunity,” Dr Panda said.

“Currently, India is far from the state of herd immunity, as more than 75% of Indians are unexposed to and uninfected with Covid-19. We should not lower our guards as yet. The vaccine is important for this very reason. If lesser people are getting affected, it is good news, but we also need to know whether sufficient tests are happening or not and the people are following proper measures. Now we have vaccines, so people should be encouraged to take vaccines because a larger proportion of people are still vulnerable to Covid, whether in Delhi or any other state of India,” he added.

The first survey which was conducted in August last year showed that over 29% had antibodies. The serological test is performed to diagnose infections and autoimmune illnesses. It is also conducted to check if a person has developed immunity to certain diseases. So far, five serological surveys have been carried out in Delhi.

Several experts also emphasize that the presence of antibodies among a large percentage of the population could be a reason for the decline in the daily number of Covid cases. If 60% or more of the population has developed antibodies against Covid, there is a possibility of acquiring herd immunity.