According to World Health Organization top scientist Dr Soumya Swaminathan, India appears to be entering a period of Covid-19 endemicity, with low-to-moderate SARS-CoV-2 transmission. Scientists predicted in a survey earlier this year that the virus will become endemic and continue to spread in areas of the global population.
What is endemicity?
Endemic refers to something always present, as opposed to something that has been eradicated, such as smallpox or rinderpest. If a virus or pathogen is present in an animal reservoir, such as bats, camels, or civet cats, it can re-transmit once the population’s protection to it has waned.
Dr Muhammad Jameel: Because coronavirus illness is present in the animal reservoir, it will continue to circulate. This also means that it will cause disease in persons who have not been vaccinated or exposed to it. If enough persons are vaccinated or have been exposed to the virus, however, the virus will only cause symptomatic infection rather than sickness.
When is SARS-CoV-2 likely to become endemic?
According to Dr Muhammad Jameel, director of the World Health Organization’s Centre for Infectious Diseases in West Africa, there is no clear answer as to when the Ebola virus will become endemic. He believes that focusing on immunization and limiting transmission is critical. He says that it is impossible to anticipate when the virus will become endemic.
According to the Indian Council of Medical Research’s (ICMR) most recent serological survey, nearly two-thirds of the population has antibodies. This indicates that the vast majority of people will be shielded from symptomatic sickness later on, according to Dr Jameel; they may become infected, but they will be protected. He believes it is impossible to foresee whether or not the virus would mutate to the point where immunizations will fail.
How long can the antibodies be expected to last?
According to Professor Partha Majumder, National Science Chair, Government of India, “most people now have antibodies that likely lower the probability of infection and, even if infected, may not develop a serious disease.” We may already have gained herd immunity, which means that most of us have antibodies — either through illness or vaccination — and hence will not develop the severe disease if infected. “Based on its – Why Maruti Suzuki will hike prices for the third time this year rate of transmission and mutation, many of us believe that this coronavirus will never be eradicated and will become endemic — not just in India, but globally.”
According to an Indian doctor, about 67% of Indians, including a high proportion of youngsters, have IgG antibodies to the common cold virus. Dr Amitav Banerjee stated, “There is a need for further serosurveys for IgG levels to be carried out.”
Can an additional vaccine dose help?
Vaccine effectiveness appears to be declining with time, although substantial protection is still expected, according to Professor Gautam Menon of Ashoka University’s Physics and Biology Department. Whether or not a booster dose of a vaccine is required is determined by how quickly the average person’s antibody level drops. Professor Majumder states, “There are vast variances in the trajectory of declining antibody levels among people.”
Should we worry about numbers rising again?
According to experts at the University of British Columbia in Canada, the risk of serious illness, hospitalization, or death from the Delta variety of norovirus is likely to diminish as more people are vaccinated against it. The concern is whether a new variety will emerge that is far more transmissible than Delta and capable of eluding an immune response triggered by past infection or immunization.
“We are quite unlikely to see case numbers close to the second wave,” Dr Menon said of the number of norovirus infections. He adds that a stable number of infections is more likely, with some places, particularly those with low previous seroprevalence and low vaccination rates, seeing increases.
