The US Food and Drug Administration has released its findings on the Pfizer/BioNtech efficacy data where it suggested that the vaccine at a single dose with 67% efficacy would work. Pfizer has said its vaccine efficacy is 97% when two doses are given at an interval of 30 days.
Similarly, Swedish British drug maker AstraZeneca that is developing a Covid-19 vaccine with Oxford University went back to the drawing-room to start a new trial with a half and full-dose vaccine.
In their findings published in the medical journal Lancet, AZ also hinted that the vaccine provided protection from SARS-Cov2 as a single dose vaccine at least for the short term.
“Efficacy was similar when evaluated starting at 21 days after the first standard dose (192 cases), suggesting there is at least short-term protection with one dose,” said the researchers from Oxford/AZ in their published findings in Lancet.
The USFDA, in its review document for Pfizer vaccine, wrote that based on the cumulative incidence curve for all available efficacy population after the first dose…there does not appear to be evidence of waning protection during the follow-up time of approximately two months following the second dose that is being evaluated at this point in time.
Earlier this week, Pfizer CEO Andres Bourla had expressed concerns if the FDA approved a single-dose vaccine, stating that when the vaccine works better as double dose why not offer that.
Gagandeep Kang, vaccine expert and professor at CMC Vellore, in a Twitter reply said, “Better to have 67% (efficacy) in double the people at first and then go around a second time with another vaccine, or 95% in a smaller number?”
Companies such as J&J, which has partnered Biological E in India, are working on a single-dose vaccine that the company is expected to launch by June next year.