A check mark. It indicates that the relevant content has been reviewed and verified by an expert Our stories are reviewed by medical professionals to ensure you get the most accurate and useful ...

It is a concept in certain infectious diseases, specifically ones that are contagious. The technical definition of HI is what occurs when a large proportion of a community (herd) becomes immune to a ...

In early 2020, scientists raced to understand COVID-19, trying their best to provide timely and accurate information to the public. As knowledge grew, experts revised their guidance on seemingly ...

Monica Hesse described in her July 15 op-ed, “There’s no vaccine for this,” her dismay at the state of U.S. measles vaccination rates. She fears that the loss of herd immunity will harm those who aren ...