AstraZeneca Plc plans to conduct a global study to find the optimal interval between the two doses of its coronavirus vaccine. “The new trial will investigate a two-month gap between shots to determine whether it can provide better efficacy,” chief executive Pascal Soriot told a group of European newspapers Tuesday.
The trial data published by AstraZeneca and Oxford raised questions after one arm of the study that received a half-dose followed by a full-dose of vaccine produced an efficacy of 90%, compared with 62% for two standard doses.
A panel of scientists behind the U.K. approval said in December that the higher efficacy seen from the half-dose regimen could be attributed to the gap between injections rather than dosing level.
“You get a better efficiency if you get the second dose later,” Soriot told the newspapers, including Italy’s La Repubblica. “We are going to do a study in the US and globally to use two-month dose interval to confirm that this is indeed the case.”
AstraZeneca executive Mene Pangalos told a UK parliamentary committee earlier this month that further analysis of the trial data suggested an increased interval raised efficacy and that an 8- to 12 week gap looked to be the “sweet spot.”
United Kingdom approved the vaccine, developed with the University of Oxford and AstraZeneca, last month with a 4-to 12-week dosing interval.
India approved emergency authorisation of Covishield by Serum Institute of India. It is the local version of Oxford-AstraZeneca COVID-19 vaccine. In India, the interval between the two dosage will be four weeks.