AstraZeneca downgrades COVID-19 vaccine effectiveness

The British-Swedish pharmaceuticals company AstraZeneca has released the phase three trial data for its COVID-19 vaccine on Thursday.

The new data proves that its COVID-19 vaccine is highly effective but it was observed that one of the figures issued on Thursday is lower than the one issued on Monday.

The UK-based company said in the updated report that the vaccine was 76 percent effective (down from 79 percent reported on Monday) in protecting against symptomatic cases of the virus and 100 percent effective against severe disease and hospitalisation.

The drug maker issued the updated report after questions were raised by a U.S. health agency earlier in the week over possibly outdated vaccine trial results.

On Tuesday, the National Institute of Allergy and Infectious Diseases (NIAID) had said concerns were raised by the Data and Safety Monitoring Board (DSMB) over initial results published by AstraZeneca from its vaccine trials.

However, AstraZeneca said the new data confirmed vaccine efficacy consistent with the figures announced on Monday, March 22.

The drug maker also noted that, according to the latest data, the vaccine was well-tolerated, and no safety concerns related to the vaccine were identified.

The company further cited that data from its phase III study with around 32,500 test subjects showed 85 percent efficacy rate for people over age 65.

This means that among the older subjects in a vaccinated group, 85 percent fewer cases of illness occurred than among those in a control group.