Delta variant is so contagious it 'raises the bar' for Covid vaccines, Moderna president says - CNBC

The fast-spreading delta variant is so contagious, it's exposed weaknesses in vaccine protection and changed the outlook for ending the pandemic, Moderna President Stephen Hoge said late Wednesday.

Moderna on Wednesday shared a new analysis from its phase three study that showed the incidence of breakthrough Covid cases, which occur in fully vaccinated people, was less frequent in a group of trial participants who were recently inoculated, suggesting the Covid vaccine's protection wanes over time.

He said he suspects the Covid cases in vaccinated people are a result of both vaccine protection waning over time and the highly transmissible variant.

"The delta variant is not an immune escape variant," he said, adding the variant is simply "weakening our defenses" at a time when vaccine protection is declining.

The move is part of President Joe Biden's broader plan to confront a higher number of Covid cases fueled by the fast-spreading delta variant