A number of vaccines produced by different companies are due to be released around the world, but just how safe are they? Is an efficacy of less than 100% a cause for concern?
On April 4th, AstraZeneca announced that its vaccine had an efficacy of 79%, based on phase 3 trial data from the United States. Less than 24 hours later, the National Institutes of Health (NIH)Trusted Source said that an independent panel of experts had raised concerns over the data.
The interim analysis of the company’s U.S. clinical trial comes after a week of turmoil in Europe, with several countries temporarily halting vaccination in response to a number of vaccine recipients developing severe blood clots and rare types of stroke.
The European Medicines Agency, however, stated last Thursday that the vaccine does not carry an increased risk of blood clots and that the benefits of having the vaccine outweigh the risk of side effects.
In their press statement, AstraZeneca reported an efficacy of 79% at preventing symptomatic COVID-19 and 100% efficacy at preventing hospitalization and severe illness.
“…several countries temporarily halting vaccination in response to a number of vaccine recipients developing severe blood clots and rare types of stroke.”