Third major vaccine shown to be effective.
AstraZeneca, Oxford report encouraging results in their trials
AstraZeneca and the University of Oxford announced on Monday that their inexpensive, easy-to-produce coronavirus vaccine appears effective, thelatest in a string of encouraging results this month from vaccine developers.
An early analysis of data from late-stage clinical trials found that the vaccine was either 62 percent or 90 percent effective, depending on the manner in which the doses were given. On average, the vaccine was 70 percent effective, AstraZeneca said.
AstraZeneca’s announcement came on the heels of Pfizer and Moderna releasing trial results that showed their vaccines to both be about 95 percent effective.
Unlike the Pfizer and Moderna vaccines, AstraZeneca’s offering can be stored for at least six months in standard refrigerators and is relatively easy and inexpensive to mass-produce.
AstraZeneca’s results could strengthen the global effort to produce enough vaccine to start defusing the pandemic: The price of the shot, at $3 to$4, is a fraction of that of some other potential vaccines. AstraZeneca has pledged to make it available at cost around the world until at least July 2021and in poorer countries in perpetuity.
AstraZeneca said it expected to begin distributing the vaccine this year and that it would be able to make up to 3 billion doses next year.
The varying effectiveness of AstraZeneca’s vaccine reflected differences in how doses were administered in the late-stage trials. In the dosing plan that was 90 percent effective, study participants were given a half-dose of the vaccine and then, amonth later, a full dose. The vaccine was less effective when people were given a standard full dose upfront, followed a month later by another full dose.
The analysis, which looked at data from participants in Britain and Brazil, did not turn up any serious safety issues
AstraZeneca has not been testing the more-effective half-dose regimen in its U.S. trials. The company said it would work with the Food and Drug Administration to add it as quickly as possible to its ongoing trial.
The company said its early analysis was based on 131 symptomatic coronavirus cases that turned up in participants at least two weeks after they had received their second shot.
None of the vaccinated people who developed the disease required hospitalization, AstraZeneca and Oxford said.
“Today marks an important milestone in our fight against the pandemic,” AstraZeneca’s chief executive, Pascal Soriot, said in a statement. “This vaccine’s efficacy and safety confirm that it will be highly effective against COVID-19 and will have an immediate impact on this public health emergency.”