What if I don’t get my second Covid-19 vaccine dose on time?

Delays in vaccinations are partially the result of vaccine supply shortages, and partially the result of fragmented, underfunded healthcare systems lacking in federal support. “It’s really not a problem,” says David Topham, a microbiologist and immunologist at the University of Rochester in New York. When the US Food and Drug Administration (FDA) granted these vaccines emergency use authorization, it did so prescribing those exact intervals for each, since that’s what they had data for.