Longer Wait Between Pfizer/BioNTech Vaccine Doses is OK, WHO Says

Pfizer/BioNTech’s COVID-19 vaccine should ideally be given in two doses 21 to 28 days apart, but due to ongoing shortages, an interval of up to 42 days is acceptable, the World Health Organization (WHO) said Friday.

“A number of countries face exceptional circumstances of vaccine supply constraints combined with a high disease burden,” the WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) said, adding that the interval between doses may be extended “on the basis of currently available clinical trial data,” subject to change as new data comes in. But national authorities that have to institute such delays must ensure that people do in fact get the second dose, SAGE says.

The UK is reportedly allowing the interval between the Pfizer/BioNTech vaccine doses to run as long as 12 weeks, and SAGE says it will consider data from this practice for future WHO recommendations.

Booster shots of the Pfizer/BioNTech vaccine are not necessary according to current data, SAGE says. And SAGE based its recommendation on the finding that reinfection with COVID-19 within six months is “rare.”

The WHO also said last week that it does not recommend the vaccination of travelers unless they are categorized as high-risk. It is unknown whether the vaccine is interchangeable with other COVID-19 vaccines, and due to a lack of data and the need for caution at least 14 days should pass between someone getting the Pfizer-BioNTech COVID-19 vaccine and any other vaccine for any other disease, SAGE says.

As market-authorized vaccines become available “specific recommendations for the use of these vaccines will need to be issued,” SAGE said in a paper released in December that outlines how the expert group takes into consideration initial data emerging from phase 3 clinical trials.

Meanwhile, members of the FDA’s vaccine advisory panel told FDAnews last week that the FDA made the right call in strongly advising against delaying second inoculations or making other changes such as using a half-dose regimen of Moderna’s COVID-19 vaccine to stretch supply and vaccinate more Americans (DID, Jan. 6).

Read the WHO recommendations here: www.fdanews.com/01-08-21-WHO.pdf. — Martin Berman-Gorvine