95.6% of COVID-19 vaccine recipients received second dose on time, CDC says

Among the millions of Americans who received both doses of the Moderna or Pfizer-BioNTech vaccines during the first 2 months of the vaccination program, most received the second dose within the recommended time frame, according to the CDC.

Reporting in MMWR, the researchers said the findings were “reassuring.”

“However, the groups prioritized to receive vaccine during this period [Dec. 14, 2020, through Feb. 14, 2021] were more likely to have been vaccinated at their work site or residence, including health care workers and long-term care facility residents, which might have facilitated adherence to the recommended schedule,” they cautioned.

The recommended interval between doses is 21 days for the Pfizer-BioNTech vaccine and 28 days for the Moderna vaccine; however, up to 42 days between doses is permissible when a delay is unavoidable, according to Jennifer L. Kriss, PhD, and colleagues from the CDC’s COVID-19 Vaccine Task Force.

Among almost 12.5 million Americans who started the vaccine series during the study period, 88% received the second dose on time, 8.6% had not received the second dose but were still within the “allowable interval” (42 days or less) and 3.4% had missed the second dose. Among more than 14 million people who completed the series by Feb. 14, 95.6% received the second dose in the recommended interval. Non-Hispanic American Indian/Alaska Natives and people aged 16 to 44 years had the highest percentages of those who missed the second dose.

“Providers should not administer second doses before the recommended interval or hold or save doses for patients who have not returned [more than] 42 days after their first dose,” the researchers wrote. “Providers should regularly assess missed second doses and repurpose those doses as first doses for eligible persons to initiate the vaccination series.”