Phase 2/3 trials show that the AstraZeneca/University of Oxford vaccine are effective against the new U.K. variant.
In a pre-print, not yet reviewed by The Lancet, Andrew Pollard, PhD, University of Oxford, claims vaccine efficacy was 74.9% (95% CI 41.6-88.9) after two doses against symptomatic infection from the B.1.1.7 variant.
CDC estimates it could be the dominant COVID-19 strain by March as cases continue to rise in the U.S, despite England testing before allowing passengers to leave. Other than this vaccine is Novavax, the only vaccine manufacturer in late-stage clinical trials to share clinical vaccine efficacy data related to the U.K. variant, with 86% efficacy against cases from B.1.1.7, according to a recent press release from the manufacturer. However, scientists did note, “these are the first published data on the clinical efficacy of a vaccine against SARS-CoV-2 against the novel B.1.1.7 variant compared with non-B.1.1.7 lineages.”
In order to complete the study, the University of Oxford in England conducted sequenced data from 323 swabs in 256 participants from October 1 to January 14. They measured COVID symptoms via a nucleic acid amplification test more than 14 days after a second dose of vaccine.
The results were interesting. They found virus neutralization activity by vaccine-induced antibodies was 9-fold lower against the B.1.1.7 variant than non-B.1.1.7 variant strains.
“These findings suggest that either lower neutralizing antibody titers are sufficient to provide protection or that other mechanisms of immunity may be responsible for protection from disease in vaccinated individuals,” the authors wrote.
Vaccine efficacy against non-B.1.1.7 variant strains was 84% (95% CI 70.7-91.4).
Among symptomatic cases where sequencing data were available, there were fewer total cases of the U.K. variant, with non-B.1.1.7 variant strains comprising 86 cases (71.7%). They noted B.1.1.7 variant cases first arose in late November in trial sites in London, but were “an increasing proportion of positive swabs” during December and January.
Also, note that this data included part of the subset of participants who received a half-dose of vaccine for their first dose.
The main risk-of-error due to limitation is made aware by the authors who acknowledged that sequences from all positive swabs could not be obtained due to “logistical constraints,” and there is, of course, a small possibility of human error during sequencing.
However, the results of the study are so overwhelmingly good that the margin-of-error is insignificant in the face of the virus variant that we desperately need to combat in order for the world to eventually go back to normal.