Pharmacists have more power in some states than patients might realize. They vaccinate, provide overdose-reversal antidotes, and even prescribe birth control, all without the patient seeing a doctor.

Beginning next year in California, giving pharmacists the authority to do more is a strategy coming into play in the battle against HIV, the virus that causes AIDS. Pharmacists will be able to provide highly effective medications to patients to prevent HIV, and influential healthcare leaders and AIDS advocates believe more states should do the same.