“The durability of immunity after infection with Covid persists for about 9 months”


The durability of immunity after COVID-19 vaccination persists for nine months or more and a preventive dose of vaccine that will be administered to healthcare and frontline workers and citizens over 60 years of age with co-morbidities aims to mitigate the severity of the infection, hospitalization and death, the government said Thursday.

ICMR Director General Dr Balram Bhargava said the SARS-CoV-2 virus infects an individual in a natural environment and causes cell-mediated immunity and immunological memory.

He said that hybrid immunity, which is developed as a result of vaccination and natural infection, generates a stronger response and robust antibody titers after the second dose.

Measuring antibody titer alone does not capture all of the protection, he said.

“The durability of immunity after infection persists for about 9 months,” Bhargava said at a press conference.

He said that hybrid immunity, which is developed as a result of vaccination and natural infection, generates a stronger response and robust antibody titers after the second dose.

“If you’ve had an infection and you’ve been vaccinated, your immune response is more than just an infection or a vaccine. So the important thing is that the vaccination is absolutely essential,” he said.

Citing global evidence, Bhargava said that the immunological memory of SARS CoV2 lasts for more than eight months after natural infection.

“This is from the United States published in Science, and there is an antibody and cellular response over nine months after infection from China. Then longitudinal surveys in the United States have shown that many studies have shown that antibody responses persist for more than 13 months after infection and a systematic review of 10 studies from Israel, England, Denmark, United States, Austria and Italy shows a reduction of more 90% of re-infection for up to 10 months, ”Bhargava said.

“… We like to say that up to nine months and take a slightly conservative estimate of that and that is what is the proof. From India there are three studies two from ICMR and one from Mumbai , on 284 patients, on 755 patients and 244 that it persists for up to eight months, seven months and six months (respectively) and these are all published data on an infection that occurred in 2020, 2021 ”, he said declared.

Speaking of the vaccines used in India, Bhargava said that one is the complete virus vaccine with an innovative adjuvant which is Covaxin and the second is a viral vector-based subunit vaccine which is Covishield.

“… So despite the vaccination, we know the seroprevalence that also needs to be taken into account. And the third point is that the transmission of Omicron is also three or four times that of the Delta variant. So that will expose also people for this. In terms of precautionary dose we have to remember an important point and this is the most important point is that all Covid vaccines are primarily disease modifying and they do not prevent infection . noted.

Bhargava said the precautionary dose is primarily aimed at alleviating the following three – one, severity of infections, two – hospitalization and death.

“Now this is very important for the elderly, immunocompromised or on chemotherapy, or patients with chronic obstructive pulmonary disease. So these are patients for whom a precautionary dose would be useful to prevent hospitalization for serious illness and death, “he said.

“The three important points on which I would like to insist on the use of the mask before and after vaccination are essential: mass gatherings should be avoided before and after vaccination. And the strains circulating earlier and now are spreading by the same route. They are all spread through the respiratory tract. by air. So we have to remember that if the virus is mutating, it is spreading through the same route, ”he said.

Bhargava said the treatment doesn’t seem to change, it stays the same. “

Home isolation remains an important parameter and hospitalization will be limited to people in particular to those who have not been vaccinated. Those who are not vaccinated will be those who will be admitted to hospitals, people who are immunocompromised and undergoing chemotherapy will be those who will be admitted to hospitals and require more care, “he added.

(Only the title and image of this report may have been reworked by Business Standard staff; the rest of the content is automatically generated from a syndicated feed.)


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