Children’s liquid Tamiflu is in short supply, the drug’s manufacturer told Reuters. Meanwhile, four of six formulations of Fluzone vaccine have sold out given the widespread flu activity in the U.S. and unanticipated late demand for vaccines.

During the liquid Tamiflu shortage, pharmacists can dissolve capsules of Tamiflu into a sweet liquid to make a quick substitute.

Over 40 states are reporting widespread flu activity. The main virus in circulation can make people sicker than usual, the Associated Press reports. However, the circulating strains appear well matched to those included in the influenza vaccine, and about 60% of people who got the vaccine are protected from the flu.

Google has a graphical representation of this year’s flu outbreak city by city based on Google searches for flu-related topics. By that measure, Boston, Miami, Dallas, Chicago, and many other cities are seeing “intense” flu activity.