By Michael Erman (Reuters) –Moderna Inc said on Thursday its COVID-19 shot was about 93% effective through six months after the second dose, showing hardly any change from the 94% efficacy reported in its original clinical trial
. That compares favorably to data from Pfizer Inc and BioNTech SE last week in which they said their vaccine’s efficacy waned around 6% every two months, declining to around 84% six months after the second shot.
Both the Moderna and Pfizer-BioNTech vaccines are based on messenger RNA (mRNA) technology.
“Our COVID-19 vaccine is showing durable efficacy of 93% through six months, but recognize that the Delta variant is a significant new threat so we must remain vigilant,” Moderna Chief Executive Stéphane Bancel said.
However, a booster dose will be necessary prior to the winter season as antibody levels are likely to wane, Moderna said.
The comment comes as public health officials across the world debate on whether additional doses are safe, effective and necessary even as they grapple with the fast-spreading Delta variant of the coronavirus.