How Long Is a Vaccine Month? By Vincent Iannelli, MD / January 2, 2019 / booster doses, boosters, calendar, catch-up immunization schedule, early vaccines, errors, intervals, late vaccines, minimum, months, spacing, Vaccine Education, weeks How long is a month when you are talking about scheduling and spacing vaccines? Share this:FacebookTwitterRedditPrintLinkedInPinterestEmailTumblrWhatsAppLike this:Like Loading...