India is not considering booster shots yet as there are no recommendations to the effect from the National Technical Advisory Group on Immunisation (NTAGI).
“The science of the need and timing of booster shots is still evolving. Different vaccines may have different schedules. It is being closely watched and studied,” Niti Aayog member (health) VK Paul told TOI last week.
However, medical practitioners, who were the first to get inoculated when the vaccination drive began on January 16 this year, are keen on taking a third dose, making ‘booster dose’ a buzzword among healthcare workers.
Many doctors TOI spoke with say that with a third wave of infections imminent, a booster shot is now inevitable especially since they work in areas where the viral load is high and are highly vulnerable to infection.
“Most vaccines that we took from childhood had booster doses,” says Dr Smitha S Segu, nodal officer for Covid management at Bangalore Medical College and Research Institute (BMCRI). “Covid too may need a booster dose. Everyone is waiting for a directive from WHO and the government. We still don’t know about the efficacy of the vaccines against new variants and there have been cases of breakthrough infections,” she says.
But some say the necessity of a third dose must be based on evidence of fewer antibodies after being fully inoculated. Dr Sujay Prasad, medical director, Neuberg Diagnostics, Bengaluru said that if Covid antibodies are less than 100 binding antibody units per ml (BAU/ml), then a booster dose is advised. “If it is more than 400 units, then there is no need to take a booster dose,” he said.
In a recent study, ICMR, said doses of two different vaccines provoked a superior immune response than two doses of the same vaccine. Researchers studied 18 of 20 individuals who were mistakenly given Covishield for the second dose after they had taken Covaxin for the first in Uttar Pradesh in April-May this year. The individuals’ blood samples were analysed at different stages for 60 to 70 days after vaccination.