Kate O’Brien, the WHO’s director of immunization, vaccines, and biologicals has agreed with Sir John Bell of Oxford University’s statement that more data will be needed from trials of Oxford and AstraZeneca’s COVID-19 vaccine to determine its safety and efficacy, commenting, “From what we understand about the press release, there is certainly something interesting that has been observed, but there are many reasons that could underlie the differences that were observed.”
At a press briefing in Geneva, she said that it was still not clear if vaccines against COVID-19 were able to reduce people’s ability to spread the virus. “It’s really important that we actually start to get more information about what the vaccines do, not just for preventing disease, but for actually preventing the acquisition of the virus,” she said.
Oxford and AstraZeneca reported that a lower dose of the vaccine performed better than a full dose in their study, with 62% effectiveness in people who received two doses, as compared to 90% effectiveness in those who received a half dose followed by a full dose. In the study, 2,741 volunteers got a half dose followed by a full dose, while 8,895 got two full doses. All the people in the half-dose regimen were below 55 years of age. The half dose was an unintentional mistake, according to the researchers.
Pascal Soriot, CEO of AstraZeneca, said that the company will begin a new study to examine the lower dosage regime. The WHO’s chief scientist, Dr. Soumya Swaminathan, said that the trial figures “are still too small to really come to any definitive conclusions,” and “If we are to explore this hypothesis of having perhaps a better efficacy with the lower dose, then it would need a trial.”
Reference: CNBC, November 27, 2020, https://cnb.cx/3omW8bN