AstraZeneca COVID vaccine 70% effective vs B117 variant
Data from a UK phase 2/3 clinical trial suggest the AstraZeneca-Oxford COVID-vaccine is 70.4% effective against symptomatic COVID-19 caused by the B117 variant, which was identified in the United Kingdom in late 2020.
The data, published in The Lancet yesterday, also showed it was 28.9% effective at preventing asymptomatic infections or cases with unknown symptoms.
Overall efficacy was 61.7% against the B117 variant and 77.3% against other variants, according to the study. The vaccine was 81.5% effective in preventing symptomatic COVID-19 caused by non-B117 strains.
In a Lancet commentary, Rogier W. Sanders, PhD, and Menno D. de Jong, MD, PhD, of Amsterdam University Medical Centers, write, “Given the wide CIs [confidence intervals] in these exploratory analyses, no firm conclusions can be drawn on the precise clinical efficacy against the B.1.1.7 variant and, importantly, how this efficacy compares with efficacy against the original circulating variants.”
Even so, they say the findings “suggest a meaningful degree of efficacy against the B.1.1.7 variant, which is encouraging.”
The AstraZeneca vaccine is being rolled out in the United Kingdom, countries participating in the World Health Organization’s (WHO’s) COVAX initiative, and elsewhere. Both the AstraZeneca and Johnson & Johnson vaccine use viral vector technology, as opposed to the mRNA method that the Pfizer/BioNTech and Moderna COVID-19 vaccines use.