Moderna and Merck announced their personalized cancer vaccine demonstrated potential in a late trial. Stock prices went up for both companies. Moderna stock surged 177 percent. Short sellers forfeited an estimated 5.5 billion dollars. The Times said Moderna aims to be a cancer-focused company.
Federal health rules were updated. The Trump administration mandated separate MMR shots. South Carolina health officials told parents to vaccinate kids before school due to a past measles outbreak. Douglas County saw a big drop in youth vaccination program attendance. The Washington Post wrote about federal vaccine fights and addressed reader questions.