Hundreds of Non-Resident Indians (NRIs) who have reached the State from the Gulf after receiving their first dose of vaccine, mostly the Chinese vaccine Sinopharm or Pfizer BioNTech, are caught in a catch-22 situation as the vaccines are not available in India for their second dose.
Most of them had returned to the State in April after getting the first dose of the COVID-19 jab, especially from the United Arab Emirates (UAE). But they are unable to fly out following the ban or restrictions on flights.
Sources said the expatriates stranded back were required to get their vaccination certificate before returning to the GCC destinations. At the same time many have returned in chartered flights or non-scheduled flights amidst the COVID-19 crisis, after paying hefty air tariffs.
Now the Centre has been urged to approve Pfizer and also the vaccine made by Chinese State-owned company Sinopharm. Last month, the World Health Organisation (WHO)granted emergency approval for Sinopharm which had already been given to Chinese nationals as well as residents in the UAE.
So far India has approved the Serum Institute of India’s Covishield version of the AstraZeneca vaccine, Bharat Biotech’s Covaxin, and Russia’s Sputnik V. The Centre is in talks with Pfizer.
With the delay in getting vaccinated for NRIs who have taken the first dose and planning the return to Gulf, suggestions have cropped up even on considering mixing different vaccine doses.
However, this heterologous immunisation has not been approved though some scientists and doctors believe using different vaccines for the second dose could have the capability to boost the immune response against the virus.
Balu Bhaskar, specialist in critical care medicine, director of intensive care services, The American Hospital, Dubai, said that “some studies have shown that if the second vaccine is different technology, it might increase the coverage of immunity. For example, if mRNA is not effective in the first dose, the viral vector vaccine of the second dose will protect the recipient. But we need more evidence on the profile of mixing and matching vaccines. Also, studies on the side effects,” Dr. Balu said.
On mixing vaccines, Vivek Rajagopal, a clinical director for general medicine attached to National Health Services (NHS) Foundation Trust, United Kingdom, said the benefits of having a second dose of a different vaccine was likely to outweigh potential adverse effects as a single dose of Sinopharm, in particular, did not provide adequate protection against the delta variant.
“Available data suggests that two doses of Pfizer vaccination gives 88% protection against developing symptomatic disease. Patients who have received one dose of Pfizer are also likely to benefit from having either Covishield or Covaxin as it will enhance the immune response,” he said.
However, Dr. Vivek said the vaccine recipients would have to make their judgement after discussion with a physician since there is no official guidance on mixing vaccines and trials were ongoing.