Dr NK Arora, chairman of COVID-19 working group under National Technical Advisory Group on Immunisation (NTAGI) has said that the country may soon start testing the feasibility of a regimen that mixes two different doses of COVID vaccines to see if it helps boost the immune response to the virus.
Speaking about the current scenario of vaccine availability in the country, Dr NK Arora said, "Yesterday, SII in a letter mentioned that from June onwards they will be manufacturing 10-12 crore doses, which is almost 50% ramping up. Similarly, Covaxin is also going to increase its production and by July end they will also produce between 10-12 crores."
"By August we will have 20-25 crore vaccine doses per month; another 5-6 crore doses from other manufacturing units or if we get international vaccine doses. The objective is to vaccinate 1 crore people every day," he added.
Dr VK Paul, Member Health NITI Aayog earlier said that taking two jabs of two different COVID vaccines is "theoretically possible", but more in-depth research is needed in the matter
Addressing a press conference, Paul said, "You asked me if a person can get inoculated with a vaccine different from the one he received in the first dose. Scientifically and theoretically's possible. But recommending this is an evolving situation. No robust scientific evidence. Only time will tell."
Many countries around the world have already started to test the efficacy of switching COVID-19 vaccines. Britain said in January it would allow people to be given a different vaccine for a second dose on extremely rare occasions, for example if the first vaccine was out of stock.
The first findings of an Oxford University-led study released on May 12 found that people who received Pfizer's vaccine followed by a dose of AstraZeneca's, or vice versa, were more likely to report mild or moderate common post-vaccination symptoms than if they received two of the same type.
Novavax said on May 21 it would take part in a mix-and-match COVID-19 vaccine trial to test the use of an additional vaccine dose from a different producer as a booster. The trial will start in June in the United Kingdom.
In USA, US Centers for Disease Control and Prevention (CDC) had updated its guidance, allowing a mix of Pfizer/BioNTech's COVID-19 vaccine and Moderna's shots with a gap of at least 28 days between the two inoculations, and only for "exceptional situations".
According to a study conducted by the Spanish university, a combination of AstraZeneca and Pfizer vaccine was entirely safe and effective in controlling the spread and prevention of the disease.
The study conducted by the Carlos III Health Institute in Spain found that the first dose of AstraZeneca followed by the second dose of Pfizer was absolutely safe and effective.
The university has backed its findings with the result of a clinical trial in which 673 participants aged below 60 years participated.