CDC data suggests vaccinees do not carry, cannot spread virus

After warning for months that people vaccinated should always be careful not to infect others, the Centers for Disease Control and Prevention suggests they may not be at much risk of transmitting the coronavirus.

“People who are vaccinated don’t carry the virus – they don’t get sick,” CDC director Dr. Rochelle Walensky told Rachel Maddow of MSNBC on Tuesday. It’s “not just in clinical trials, but it’s also in real world data.”

Walensky was referring to a new CDC study that suggests people fully inoculated with vaccines produced by Moderna and Pfizer do not transmit the virus. Researchers looked at how the vaccines protected nearly 4,000 healthcare workers, first responders and other essential workers working in eight locations across the United States from the virus and more contagious variants. After a single dose of either vaccine, participants’ risk of infection was reduced by 80 percent, and this figure rose to 90 percent after the second dose. Without infection, people are unable to spread the virus. The results are similar to what scientists saw in clinical trials for vaccines, which found that two doses of either vaccine in two doses had an effectiveness rate of around 95%.

The study is the agency’s first to analyze the effectiveness of vaccines in frontline working-age adults, who are at higher risk of being exposed to and spreading the virus. “These findings should offer hope to the millions of Americans receiving COVID-19 vaccines every day and to those who will have the opportunity to roll up their sleeves and get vaccinated in the weeks to come,” Dr. Rochelle Walensky, director of the CDC, said in a statement. “Licensed vaccines are the key tool that will help end this devastating pandemic.” Still, the CDC hasn’t released new guidelines on how vaccinees should behave; its current orientation is that they continue to take precautions such as masking.

More than 142 million doses of Moderna and Pfizer vaccines have been administered in the United States as of March 30, according to the CDC. The third vaccine currently on the U.S. market is a single-dose vaccine manufactured by Johnson & Johnson, which has been shown to be 66% effective in countering moderate to severe illnesses associated with COVID-19.