In recent days, doctors in some of Greece’s most popular island destinations have reported an increase in cases, primarily among teenagers and young adults on vacation. As a result, physicians at health centers on several popular islands have prescribed hundreds of antiviral treatments in recent weeks. The data are used both for epidemiological surveillance and to determine which virus strains will be included in the next season’s influenza vaccines. She cited data from Greece’s National Public Health Organization (EODY), which show that community positivity rates remained below 10% through early July. The virus strains identified include both influenza A and influenza B.