CDC Shifts, Says Some Should Consider Waiting 8 Weeks Between COVID Shots

The Centers for Disease Control and Prevention (CDC) recommended people in certain age groups wait up to eight weeks between their first and second COVID-19 vaccine doses.

The health agency has shifted its advice to suggest the eight-week interval could be beneficial for those between the ages of 12 and 64, especially males between 12 and 39 years old.

About 27 percent of Americans have not yet received the vaccine, according to the Associated Press, meaning this change would affect those who have decided to get the vaccine later than most people. The decision to space out the shots was made after research showed the longer wait period could create a more "enduring protection," CDC officials told the AP.

The CDC's updated COVID-19 advice added that the longer interval has also shown to lessen the risk of myocarditis, or heart muscle inflammation that causes chest pain, shortness of breath and a feeling of one's heart pounding. Myocarditis is a rare side effect some people, mostly adolescent and young adult males, experienced after getting the vaccine, usually following the second dose. According to the CDC, most of the patients with this side effect quickly recovered.

The CDC said while the "absolute risk" of this side effect "remains small," the longer interval lessens the risk even more, adding that a period longer than eight weeks did not show any additional benefit.

The agency continues to recommend the previous three-to-four-week interval for those over 65 years old, immunocompromised people and others at higher risk of severe disease.

According to Politico, health experts hope this update will encourage some younger people concerned about the myocarditis risk to get the vaccine, as those between 12 and 40 years old are the most likely to not be vaccinated.

COVID-19 data from Reuters shows cases have been decreasing in nearly every U.S. state, following a trend of cases around the world falling from their January peaks led by the Omicron variant. The only state with cases still rising was Maine, though WABI-TV, a local news station, reported that this is in part due to a backlog of cases only recently being processed.

For those who already received two vaccine doses concerned they missed their chance at the strongest protection by only waiting three or four weeks between the shots, Dr. William Schaffner, a vaccine expert at Vanderbilt University, told the AP the solution is getting a booster dose.

"We really have very good data indicating that two doses plus the booster provide very strong protection against severe disease," he said.

Update 02/23/22 1:10 p.m. ET: This story was updated to add more information.

COVID-19 vaccine, Chicago
The CDC has recommended some age groups wait up to eight weeks between their first and second COVID-19 vaccine doses. Above, the vaccine is stored at -80 degrees Celsius in the pharmacy at Roseland Community Hospital on December 18, 2020, in Chicago. Photo by Scott Olson/Getty Images