mixing

In the past few weeks, scientists have been raising the alarm about new variants of the coronavirus that carry a handful of tiny mutations, some of which appear to make vaccines less effective.But it's not just these small genetic changes…

The Centers for Disease Control and Prevention have tacitly changed their guidelines for Covid-19 vaccine shots, stating that it is now okay to mix up Pfizer and Moderna shots in "exceptional situations" and that it is okay too to wait up…