Moderna and Merck announced their personalized cancer vaccine yielded positive results in a late trial. Stock prices climbed 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 shifted. The Trump administration required separate MMR shots. South Carolina health officials instructed parents to vaccinate kids before school due to a past measles outbreak. Douglas County experienced a big drop in childhood immunization program participation. The Washington Post covered federal vaccine fights and addressed reader questions.