Axios Des Moines: At least 61,773 Iowans have skipped, missed or delayed getting their second dose of COVID-19 vaccine, according to IDPH data Axios obtained this week through a records request. Data is limited on the vaccines' effectiveness when second doses are administered beyond the recommended time frame. For Pfizer, that's 21 days; for Moderna, 28. But a second dose may be given up to six weeks after the first if necessary, according to the CDC. Nationally, at least 5 million people missed their second doses. Side effect fears rank among the top reasons.