Delaying 2nd Covid vax dose in under 65 may cut deaths: Study

Source : IANS 2021-05-13 14:22:22

A team of US researchers has found that delaying the second dose of Covid-19 vaccines, at least for people aged under 65, could result in up to 20 per cent lower mortality, but only under certain conditions.

These conditions include a one dose vaccine effectiveness (efficacy) of 80 per cent or higher and vaccination rates of 0.1 per cent to 0.3 per cent of the population per day, according to the study, published by The BMJ.

If these conditions apply, the strategy could prevent between 47 and 26 deaths per 100,000 people, respectively, the study noted.

"Decision makers will need to consider their local vaccination rates and weigh the benefits of increasing these rates by delaying a second dose versus the risks associated with the remaining uncertainty in this strategy," write researchers including Thomas C. Kingsley, Assistant Professor of Medicine at Mayo Clinic, Minnesota.

"These decisions should continue to be re-evaluated as new data become available," the researchers added.

Both the Pfizer and Moderna covid-19 vaccines in a standard two dose schedule are highly effective at preventing symptomatic infections and death. But immunity worldwide remains low, partly owing to low vaccination rates.

The longer it takes to effectively vaccinate the global population, the greater the likely risk of vaccine resistant strains developing. This has led to calls to prioritise single dose vaccination for as many people as possible, even if this means delaying a second dose beyond the studied time frame.

"The justification for this relies on the assumption that meaningful protection against Covid-19 can be achieved after a single dose of vaccine, but this is the subject of intense debate," the team said.