During the second COVID wave when cases were growing exponentially; unfortunately, the vaccination rate took a downturn. As of 27th April, when the growth rate of active infection was ~5% and the growth of vaccinated people was just 1.4%. We need to modify vaccination strategy based on scientific evidence and with the objective that a larger set of the population can be covered in the shortest duration.
AIG Hospitals, Hyderabad recently published a study conducted on 260 healthcare workers who got vaccinated between 16th Jan and 5th Feb in the International Journal of Infectious Diseases (a peer-reviewed journal). The study was designed to assess the immunological memory response in all those patients. All patients were given the COVISHEILD vaccine.
The two significant observations that came out of the study.
(1) The previously infected group (people who got infected with COVID-19) showed a greater antibody response to a single dose of vaccine compared with those who had no prior infection.
(2) Memory T-cell responses elicited by a single dose of vaccine were significantly higher in the previously infected group compared with those who had no prior infection.
It was concluded that higher memory T and B-cell responses in addition to higher antibody response with a single dose of vaccine given at 3-6 months after recovery from COVID-19 may be considered at par with two doses of vaccine for individuals already infected with COVID-19.
Commenting on the impact that this study can have on the overall vaccine administration strategy, Dr. D Nageshwar Reddy, Chairman, AIG Hospitals, and one of the co-authors in the said study said “The results show that people who got infected with COVID-19 need not take two doses of vaccine yet with a single dose can develop robust antibody and memory cell response at par with two-doses for those who didn’t get the infection. This will significantly help at a time when there’s a shortage of vaccine in the country and more people can be covered using the saved doses.”
Dr. Reddy further added that “Once we attain the requisite number of people vaccinated for achieving herd immunity, these patients who got infected and received only one dose can take the second dose of the vaccine. At this point, all our strategies should be directed at the widespread distribution of available vaccines and to include the maximum number of people at least with a single dose.”