Fauci: Viral Load in Breakthrough Delta Cases ‘Almost Identical’ to Unvaccinated

They "can spread the virus to other people," said Fauci, referring to vaccinated people who are now known to carry the same viral load as unvaccinated people.

A recent UK study on over 200,000 people shows that the vaccine effectiveness against infection by Delta variant can be as low as 49%, which is "consistent" with the estimate of 39% by Israel's Health Ministry.