Pennsylvania's Department of Health is sponsoring free flu shot clinics across the state this week.

Department spokeswoman Holli Senior said Monday there have already been more than 100 documented flu cases in Pennsylvania.

"So far this year we've been seeing pretty much two strains circulating. Which is an AH3N2 strain, and also the 2009 H1N1 strain," said Senior. "Seasonal influenza vaccine this year actually will cover both, it will protect you against both of these strains, and also an influenza B."

Senior said flu season peaks in January, so early December is an ideal time to get a shot.  Vaccinations will be offered at 60 health centers across the state on Thursday, Friday and Saturday.

Officials recommend flu shots for everyone 6 months and older. Senior said people can schedule a shot at a Health Department website, padohclinicappt.com.

The free shots are part of National Influenza Immunization Week.