Hyderabad: As the nation faces a shortage of COVID-19 vaccines, Dr. D Nageshwar Reddy, the Chairperson of Asian Institute of Gastroenterology (AIG) Hospitals, says it is important to use vaccine stocks intelligently.
The research conducted by AIG Hospitals, Hyderabad, suggesting that a single dose of Covishield vaccine is enough for at least twelve months for those who have recovered from the SARS-CoV-2 infection, was published in the peer-reviewed journal, International Journal of Infectious Diseases.
Sharing details about the same, Dr Reddy told ANI, “To test the theory, we administered a single dose of vaccine to two groups of hospital employees; those who had recovered from COVID-19 infection, and those who had never contracted the infection”.
On matching their samples for a response to a single dose of vaccine, “We found that those who did not have any infection prior developed about 100 units of anti-neutralizing antibodies. Whereas, those who were infected once had 1000 units of anti-bodies, which is 10 times more the anti-body response,” he added.
Further, Dr Reddy explained that high anti-bodies alone do not suggest robust immune phenomenon protection, and therefore, CD4 and T memory effector cells were tested.
“When we looked at these cells to see how much memory was stored, we found that those who were previously infected, and received their first dose of vaccine produced three times more of memory cells and the ones who were never infected,” Dr Reddy told ANI.
He mentioned that these cells were a good indicator of long-term immunity, and after a single shot, these cells can be very effective in providing immunity for at least 12 months.
“We believe that if a person has already had COVID infection; say 3 months or 6 months before he takes a single dose of vaccine…it will protect them for 12 months. The booster dose can be taken after 12 months”, he said.
Saying that this would avoid giving unnecessary vaccines, and would also allow vaccinating those who really need it, Dr Reddy mentioned that the institute has been planning to test other available vaccines for the same, and if the results obtained were uniform, giving COVID infected people a single dose for 12 months will be standardised.