The trial showed the vaccine is “safe and effective at preventing covid-19, with no severe cases and no hospitalizations, more than 22 days after the first dose,” the Cambridge, U.K., pharmaceutical titan said in a statement.
“Results demonstrated vaccine efficacy of 76% after a first dose, with protection maintained to the second dose. With an interdose interval of 12 weeks or more, vaccine efficacy increased to 82%.”
Further, “[the] analysis also showed the potential for the vaccine to reduce asymptomatic transmission of the virus, based on weekly swabs obtained from volunteers in the U.K. trial,” AstraZeneca said.
“The data showed that PCR [polymerase chain reaction] positive readings were reduced by 67% after a single dose, and 50% after the two-dose regimen, supporting a substantial impact on transmission of the virus.”
The Phase 3 trial included 17,177 participants accruing 332 symptomatic cases in the U.K., Brazil and South Africa.
AstraZeneca American depositary receipts recently traded at $50.23, up 0.3%. They gained 15% over the six months through Tuesday amid enthusiasm for the vaccine.
Morningstar analyst Karen Andersen puts fair value at $55 for the stock. Her view of the company might improve after the latest test results.
She wrote last month that “we remain skeptical of AstraZeneca's ability to penetrate the U.S. market due to mixed phase 3 data so far.”