Yellow Fever vaccination is NOT mandatory in Panama. & Not mandatory for Tourists.

Malaria is infrequent but not impossible. There are other mosquito-transmitted diseases like Dengue Fever that are not preventable by meds or vaccines. The best recommendation, if you're going to be outside anywhere in Panama, use DEET, just like you would in the U.S. to prevent West Nile.

Panamanian authorities spray various areas during the year to counter act the breeding of the mosquitos.They have also started clean up campaigns to remove dumped cars, drums etc that catch water and become breeding grounds for the mosquitos.

Vaccinations in Panama are provided for free by the government only during high density mosquito problems in certain areas and otherwise only if your entitled to Social Security here in Panama.

Advice, if your concerned get a vaccination before coming otherwise just do as the locals do and use repellent.

Emergency medical assistance is spotty to non-existant outside Panama City and David. Check with your hotel or resort about medical response. (Assume most are not prepared though.)  If they tell you the local public health clinic is nearby, that's not to be taken as very reassuring. 

Bring prescriptions with you though carry a copy of the prescription or receipt in case customs asks you about it. While most medical items are avialable here, some prescriptions are not or have limited availability. To be safe, if you have special prescription drug needs, assume it is not available.