COVID vaccine: Most people are getting their second shots on time, new CDC data shows
New data from the Centers for Disease Control and Prevention, which was obtained by CBS News, shows that 96% of Americans are receiving their second shot of the COVID-19 vaccine within four days of their scheduled dose.
The data, set to be released Wednesday, points to success following the two-dose schedule outlined by Pfizer and Moderna, the makers of the two available COVID-19 vaccines in the U.S.
One reason for this success has been reliability in shipments of second doses. Dr. Nirav Shah, director of the Maine Centers for Disease Control, told CBS News that his state has yet to experience any delays in second dose shipments and added that the ordering process ensures allocations of second doses will match quantities of first doses.
Last month, officials at the CDC published new guidance for those unable to meet the recommended dosing schedule: 21 days for Pfizer's vaccine and 28 days for Moderna's. The CDC said second doses of these vaccines could be taken up to six weeks after the first, but emphasized they were not recommending such a shift.
According to trial data released by the two vaccine makers, there's little data on the efficacy of missing the dosing schedule. For example, out of the more than 15,000 people who received the vaccine in Moderna's phase 3 trial, only 81 received doses out of the trial window. Data from Pfizer's phase 3 trial indicates some protection after one dose, but the company noted, "These data do not provide information about longer term protection beyond 21 days after a single dose."
"We're not advocating for people to delay getting their second dose," said Dr. Jay Butler, deputy director for infectious diseases at CDC, during a briefing in January hosted by the Infectious Diseases Society of America. "But the data from the clinical trials support this range." This guidance mirrors the extended interval suggested by the World Health Organization.
Although the CDC's new data reflects success in early efforts to administer second doses, it may be tougher as the vaccine rollout expands. In an interview with CBS News, Dr. Anne Zink, Alaska's chief medical officer, said the difficulty in administering the second shot is heightened among more rural communities, where people might seek health care in cities far from where they received their first shot.
Zink shared a story online about one doctor who independently drove a single, second dose to a patient who was in the hospital after breaking her hip. The patient "was crying tears of joy."
A third vaccine, from Johnson & Johnson, requires only one shot and the company recently applied for emergency approval from the FDA. Federal regulators are scheduled to review the company's clinical trial data on February 26.
As of February 10, 33.8 million Americans have received at least one dose of COVID vaccine while 10.5 million have received both doses, per CDC data.