Soaring COVID-19 case numbers fueled by the rapidly-spreading delta variant have prompted concerns, even among vaccinated individuals, although public health experts widely assert so-called breakthrough infections are typically rare.
But in a change of course, the Centers for Disease Control and Prevention recently acknowledged vaccinated people "are able to readily spread the virus." The message was included in an internal CDC presentation obtained by NBC News that concluded breakthrough infections "may be as transmissible as unvaccinated cases.”
Virus levels can be as high in breakthrough cases as in unvaccinated people, even if vaccinated people don’t get nearly as sick. The higher levels also persist for longer than was seen with previous strains, meaning an infected person is likely contagious for longer, researchers revealed.
Still, most outbreaks involve unvaccinated individuals, CDC Director Dr. Rochelle Walensky said last week. As of July 22, 97% of patients hospitalized with COVID-19 were unvaccinated, according to data from the University of California Davis Health.
Approximately 0.04% of the 160 million people fully vaccinated in the U.S., which amounts to 65,000 people, have reported breakthrough cases, researchers stated.
Most vaccinated people either have no symptoms or exhibit very mild symptoms, according to the health system, and the virus rarely results in hospitalization or death for those individuals.
The symptoms are similar to those of a common cold, such as cough, fever or headache, with the addition of significant loss of smell. According to Yale Medicine, research shows people with breakthrough delta cases carry tremendous amounts of virus in their nose and throat, and may be contagious whether or not they have symptoms.
Whether vaccinated or not, doctors say it's important to follow prevention guidelines from the CDC including wearing masks and watching out for possible COVID-19 symptoms.
"“Like everything in life, this is an ongoing risk assessment,” said Dr. Inci Yildirim, a Yale Medicine pediatric infectious disease specialist. “If it is sunny and you’ll be outdoors, you put on sunscreen. If you are in a crowded gathering, potentially with unvaccinated people, you put your mask on and keep social distancing. If you are unvaccinated and eligible for the vaccine, the best thing you can do is to get vaccinated.”