The durability of immunity post COVID-19 vaccination persists for nine months or more and a precautionary dose of vaccine which will be administered to healthcare and frontline workers and citizens above 60 years with comorbidities is to mitigate the severity of infection, hospitalisation and death, the government said on Thursday.
ICMR Director General Dr Balram Bhargava said the virus SARS-CoV-2 infects an individual in natural settings and elicits antibody mediated, cell mediated immunity and immunological memory.
He said hybrid immunity, which is developed as a result of vaccination and natural infection, mounts a stronger response and robust antibody titres after the second dose.
Measuring antibody titre only, does not capture the entire protection, he said.
"The durability of immunity post-infection persists for about 9 months," Bhargava told a press conference.
He said hybrid immunity, which is developed as a result of vaccination and natural infection, mounts a stronger response and robust antibody titres after the second dose.
"If you have had an infection and vaccination your immune response is more than only infection or vaccine. So the important thing is that vaccination is absolutely essential," he said.
