NEW YORK (AP) — About nine out of 10 people who got a first shot of a coronavirus vaccine got the second in the two-dose series, according to the first federal study to look at how many are people are completing the series.
The Centers for Disease Control and Prevention on Monday released results of a study of 12.5 million people who received the first vaccine dose and for whom sufficient time elapsed to get the second. The study focused on the period from December 14 to February 14.
The researchers found 88% completed the series, and another 9% did not but still had time to complete the series within the six weeks that CDC officials recommend as the maximum span between doses. About 3% did not complete the series within six weeks, the study found.
“This is good news. We think these findings are really encouraging. The fact that most people are completing the two-dose series to be fully vaccinated shows the system’s working,” said Robin Toblin of the CDC, one of the study’s authors.
The study did not explore why some people did not complete the series.
Researchers found completion rates varied from state to state. It was as low as 75% in Utah and as high as 96% in West Virginia.
There may be different reasons for state differences, including winter weather that could have delayed vaccine deliveries and caused the cancellation of vaccination clinics, Toblin said.