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At least one of the studies that was cited by the Centers for Disease Control and Prevention (CDC) to justify changing their guidance on masks was based on a vaccine that is not authorized for use in America and was rejected by a peer review.

The study in question from researchers in India analyzed vaccine breakthrough in over 100 healthcare workers and claims to show that a COVID-19 Delta variant infection generates a higher viral load in comparison to other variants.

Despite no mention in the study of viral loads from the variant against unvaccinated individuals, the CDC cited it in yesterday's updated brief as evidence that the Delta variant is transmissible from a vaccinated individual with a breakthrough infection.

"Studies from India with vaccines not authorized for use in the United States have noted relatively high viral loads and larger cluster sizes associated with infections with Delta, regardless of vaccination status," the CDC said.

"These early data suggest that breakthrough Delta infections are transmissible," the CDC's brief goes on to say, even though the India study was conducted with a non-approved U.S. vaccine.


The report from the CDC also says that "unpublished" and "additional data collection" studies are pending that will help to "understand the level and duration of transmissibility from Delta vaccine breakthrough infections in the United States and other settings."

When announcing the change in guidance Tuesday, CDC Director Rochelle Walensky cited the "recent studies" showing that breakthrough infections from the Delta variant can be transmissible.

"We're seeing now that it's actually possible if you're a rare breakthrough infection that you can transmit further, which is the reason for the change," Walensky said.

In addition to the study being conducted with a vaccine not approved in the U.S., the study that was cited by the CDC was initially rejected after a peer review and currently remains under revision.


The CDC yesterday abruptly reversed its guidance and now recommends vaccinated Americans resume wearing masks indoors under certain circumstances to protect from the Delta variant. The agency also recommended children and teachers wear masks in schools regardless of vaccination status.

Both the agency and Walensky have been widely criticized for its seemingly arbitrary guidance on how to respond to COVID-19. The agency also came under fire after it was revealed it coordinated school re-opening guidance with America's largest teacher's unions.