Moderna and Merck announced their personalized cancer vaccine yielded positive results in a late trial. Stock prices increased for both companies. Moderna stock rose 177 percent. Short sellers forfeited an estimated 5.5 billion dollars. The Times said Moderna plans to become a firm focused on cancer.
Federal health rules shifted. The Trump administration ordered separate MMR shots. South Carolina health officials instructed parents to vaccinate kids before school due to a past measles outbreak. Douglas County saw a big drop in childhood immunization program participation. The Washington Post reported on federal vaccine fights and answered reader questions.