SEATTLE — Some clinics and hospitals, including UW Medicine in Seattle, are stretching out the recommended time between COVID-19 vaccine doses due to limited supply.
The Centers for Disease Control and Prevention (CDC) recommended healthcare providers give the second dose of the Moderna vaccine four weeks after the first shot. Doses of the Pfizer-BioNTech vaccine are supposed to be given three weeks apart, according to the CDC.
If it’s not feasible to adhere to those recommended intervals, for example, because of limited supply, the CDC said the second dose of both vaccines can be given up to six weeks after the first.
Officials with UW Medicine said some patients will wait six weeks between doses.
“Your vaccine will still be safe and effective within this full timeframe,” UW Medicine said on its website.
Dr. Deborah Fuller, a professor in the Department of Microbiology at the UW School of Medicine, has studied vaccine dosing timeframes and said the longer window shouldn't stress patients out.
"The immune cells that are primed by the first dose are going to be there, they're going to be ready to respond whether you get your [second dose] at three, four, five, or six weeks, it's still going to work just as well," she said.
Overlake Medical Center and Hospital said it's scheduling second doses within the three to six-week CDC-recommended timeframe.
The CDC said it's not advocating for a delay in dosing, but data from clinical trials back up their guidance about the six weeks option.
Dr. Anthony Fauci, President Biden's top medical adviser, said providers should avoid dosing delays whenever possible.
"We have continued to go by the fact that we feel the optimal approach would be to continue with getting as many people on their first dose as possible but also making sure that people on time get their second dose," Fauci said, Monday.