“This (taking the second dose of a different vaccine from the first dose) could vastly increase the flexibility of the national vaccine rollout strategy in a pandemic,” a senior government official in the know of discussions at the advisory body told ET. The body makes its recommendations to the ministry of health and family welfare (MoHFW).
“If this comes through, then it will also allow people such as ones travelling abroad to take a second shot of whichever vaccine is available,” the official added.
Since the technology behind vaccines may vary, only the combinations and permutations, which have been successfully tested may be used, the official said. The government will have to decide whether to go by the trials abroad or water down the guidelines around trials in India like it did by allowing vaccines in the country approved by the USFDA, Japan and EU.
Sharp Fall in Pace of Vaccination
The discussions come at a time India is facing a severe vaccine shortage and many states are unable to administer the second dose, or even the first dose.
The pace of vaccination has fallen sharply. Just about 1.2 million people were vaccinated on Wednesday, a fall from the over 3.2 million vaccinated in a day five weeks ago.
According to government’s estimates, ramping up production of Covishield and Covaxin along with the entry of newer vaccines in the market will lead to availability of over 2 billion doses between August and December.
More Vaccines on the Way
Covishield, Covaxin and Sputnik V are already in the market while the government expects Biological E’s subunit vaccine,
Cadila’s DNA vaccine, Serum Institute’s Covavax (Novavax), Bharat Biotech’s nasal vaccine, Gennova’s mRNA vaccine to be available in India later this year. Besides, the government has said that vaccines from , Moderna and Johnson & Johnson may be available in some months.
“Technically, there is no reason why vaccines for the same virus cannot be mixed. The reason why the same vaccine is given twice is simply because each pharmaceutical company while developing a vaccine, used the second shot of the same vaccine,” the official said.
He added that the priority was to check whether mixing was safe enough, given that there has been growing demand from various quarters within the government and even pharmaceutical companies to explore the possibility.
A government-backed trial in the UK looking at combining vaccines was expanded last month after initial results showed it was not just safe but it might give broader and longer-lasting immunity even against new variants. In the study, people who received a first dose of Pfizer were either given the same vaccine or
and vice-versa. Going forward the study will include Moderna and Novovax as alternates.
The preliminary results of a similar study undertaken by the Spanish health authorities have also found that giving a second shot of Pfizer’s vaccine to people who received the first shot of AstraZeneca vaccine was highly safe and effective. The study had also revealed that only about 1.7% of the 670 participants had reported severe side effects, which cannot be called serious in nature.