Pfizer vaccine doses more effective with a 12-week gap on recipients under 65: Study

As India increases its interval between two doses of Covishield vaccine to 12-16 weeks, a British study has revealed on Thursday, that a delay in second dose by 12 weeks among people younger than 65 leads to fewer people dying, based on a set of conditions. According to the study done in Britain which follows a 12-week gap between Pfizer doses, it showed protection against the death of around 80% from one dose, with a 70% decline in infections. The UK uses a 12-week gap cycle for all vaccine doses administered to its citizens and has administered 5.42 crore doses till date.

Pfizer dose with 12-week gap more effective for under 65-yr olds

The study published in the British medical journal (BMJ) states, "The results suggest that under specific conditions a decrease in cumulative mortality, infections, and hospital admissions can be achieved when the second vaccine dose is delayed". The study included varying levels of vaccine efficacy and immunisation rates and different assumptions on whether the vaccine prevents transmission and serious symptoms or only prevents serious symptoms and death. The study is based on the condition that the vaccine has a one-dose efficacy of at least 80% and the daily immunisation rates range between 0.1% and 0.3% of a population. If these conditions are met, a delayed second-dose strategy could prevent between 26 and 47 deaths per 100,000 people compared to the usual schedule, stated the study.

On Thursday, on the recommendation of the National Immunization Technical Advisory Group on Immunization (NTAGI), the Centre has increased the gap between two doses of Covishield to 12-16 weeks and no change for Covaxin dosage interval. In March, NTAGI had revised the interval between doses from 4-6 weeks to 4-8 weeks, based on 'emerging scientific evidence'. Moreover, NTAGI has also recommended deferring vaccination of those testing positive for COVID-19 by atleast six months after recovery. The panel has also stated that pregnant women may be offered a choice to take any COVID-19 vaccine and that lactating women were eligible for jabs any time after delivery.

Pfizer/Moderna less efficacious but effective against B.1.617: WHO

COVID vaccines developed by Pfizer/BioNTech as well as by those by Moderna were less efficient against the double mutant virus discovered in India, stated the WHO on Thursday. As the B.1.617 lineage continues to jump international borders, the World Health Organisation (WHO) stressed that there was a limited reduction in the neutralization of the virus by the anti-bodies. However, the US vaccines - Pfizer, Modern and Johnson & Johnson are effective against the variant found in India.