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Vaccine gap may prove advantageous

The 12-16 weeks gap for Covishield will not only boos its efficacy but also help vaccine administration effectively and provide breathing space to the governments for improving supply

By M. Sai Gopal

Updated On - 14 May 2021, 12:05 AM

Vaccine gap may prove advantageous — This is for the second time that NTAGI has recommended a change in vaccine dosage in the country. — File Photo

Hyderabad: The recommendations of National Technical Advisory Group on Immunisation (NTAGI) to extend the gap between two doses of Covishield and a wait of at least six months for individuals who have just recovered from Covid-19, could help carry out vaccine administration effectively, provide breathing space to the State government for improving vaccine supply and has the potential to improve vaccine efficacy.

The NTAGI recommendations are in line with the vaccine advisories of World Health Organisation (WHO), European Medicines Agency (EMA) and other European countries who are already implementing a gap of 12 weeks to 16 weeks for the Oxford/AstraZeneca vaccine.

The dosing gap of 12 weeks more for Covishield could also provide better protection for individuals, as a study by Oxford researchers, published in British Medical Journal (BMJ) has indicated that vaccine efficacy improved up to 82.4 per cent. The gap would also enable health authorities to protect more people by administering first dose of the vaccine.

“The study has found that the vaccine efficacy reached 82.4 per cent with a dosing interval of 12 weeks or more. If the two doses were given less than six-week apart, efficacy was only 54.9 per cent,” the BMJ article while referring to the study in February, 2021, said.

Another UK study, which was published in The Lancet in March, said that a 12-week gap between doses will have a vaccine efficacy of 81.3 per cent while a shorter interview of six weeks or less provides a vaccine efficacy of 51 per cent. Based on these studies, Spain had decided to extend the gap between the first and second doses of AstraZeneca vaccine by 16 weeks.

This is for the second time that NTAGI has recommended for a change in vaccine dosage in the country. It was in March, 2021 when the Union Health Ministry decided to change from 18 days to six to eight weeks for better results.