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COVID-19: Rise, fall in cases 'common' when disease transitions to endemic phase, say experts

COVID-19: Rise, fall in cases 'common' when disease transitions to endemic phase, say experts

Dr. Sanjay Rai, a senior epidemiologist at AIIMS, said SARS-CoV-2 is an RNA virus that has already seen over 1,000 mutations even though the number of variants of concern is only five.

COVID-19: Rise, fall in cases 'common' when disease transitions to endemic phase, say experts COVID-19: Rise, fall in cases 'common' when disease transitions to endemic phase, say experts

Rise and fall in cases from time to time is a common phenomenon when an infectious disease transitions from pandemic to endemic phase, experts said on Friday as India witnesses an upward trend in Covid infections.

Underlining the current rise in coronavirus cases is so far limited to certain districts of the country, they said not wearing masks, increased travel and social interactions, and low uptake of booster doses of Covid vaccine could be behind the increase.

Dr. Sanjay Rai, a senior epidemiologist at AIIMS, said SARS-CoV-2 is an RNA virus that has already seen over 1,000 mutations even though the number of variants of concern is only five.

Even in the case of the Omicron variant, mutations happened in the receptor-binding domain which increased the chances of reinfection and breakthrough infections, he told PTI.

The trend of cases rising repeatedly is a ''common phenomenon'' when a disease transitions from pandemic to endemic phase, said Dr. Rai who is also the principal investigator of Covaxin trials for both adults and children at AIIMS.

As long as there is no increase in severity or dramatic changes in hospitalization and death numbers, a sheer increase of cases is not a cause of concern, he said. Maharashtra, Kerala, Delhi, Karnataka, Tamil Nadu, Haryana, Uttar Pradesh, Telangana, West Bengal, Gujarat, Goa, and Punjab have been recording an increase in weekly cases and positivity since June 10.

According to official sources, 51 districts in India, including 12 from Kerala, seven from Mizoram, and five each from Maharashtra and Assam, are reporting a weekly Covid positivity rate of over 10 percent.

In 53 districts, including 10 from Rajasthan and five from Delhi, the weekly positivity is between five and 10 percent, they said.

''India witnessed a very devastating second wave of Covid infections last year which was very unfortunate. But it has led to the development of a community-level natural immunity against SARS-CoV-2. ''Global evidence shows that natural infection provides better and longer protection against COVID-19. Also, there has been a high vaccination coverage. Hence, a severe wave in the future is unlikely until a new mutant variant is capable of invading the existing natural immunity and causing severe disease,'' Dr. Rai added.

Dr. Chandrakant Lahariya, an epidemiologist and infectious diseases physician, said SARS-CoV-2 is as much around as it was a few months ago. ''Therefore, a rise and fall in the number of infections from time to time are very much expected because that is how infectious and respiratory diseases behave. This is why every rise in cases is not a reason of concern or worry,'' he told PTI. Also, a large proportion of India's adult population has received two shots of COVID-19 vaccines, and a majority in all age groups are estimated to have developed immunity after natural infection, Dr. Lahariya said. So, people have developed hybrid immunity which protects them from subsequent infections resulting in symptomatic diseases, he explained.

''Moreover, 27 months into the pandemic, tracking daily new cases is not a good parameter to assess the spread. It simply reflects that the virus is around and we already know that.

''Now is the time to track Covid-related hospitalizations and severe clinical outcomes. If these parameters do not change drastically, there is no need to worry,'' Dr. Lahariya said.

He said that whether Covid has become endemic or is still pandemic is of limited practical relevance.

''However, it is fair to conclude that COVID-19 is not a population-level challenge anymore, it is more of an individual risk now. Therefore, government interventions should be more targeted at vulnerable people. It is time individuals assess their risk and determine what Covid appropriate behavior they wish to adopt,'' he said.

Dr. Samiran Panda, Additional Director General at ICMR, said these spike in cases remain restricted to certain pockets in districts and cannot be seen as a general rise in infections for the entire district or state.

''These occasional localized upward trends, fortunately, are not associated with severe disease, hospitalizations, and deaths.

However, the use of masks would offer protection not only against Covid but also from other diseases such as tuberculosis as well as air pollution,'' Dr. Panda said.

Published on: Jun 24, 2022, 4:54 PM IST
Posted by: Tarab Zaidi, Jun 24, 2022, 4:38 PM IST