Leerink analyst David Larsen sees less than 1% impact to revenues and earnings to companies in his coverage from Hurricane Harvey and Irma and believes any effects will be viewed as one-time in nature. The analyst notes that "the percentage of state impacted" and "days of impact" are particularly challenging variables in his model to estimate, but based on various assumptions he believes the hurricanes will prove to be a minor event for Express Scripts (ESRX), AmerisourceBergen (ABC), Cardinal Health (CAH), and McKesson (MCK). Nonetheless, Larsen says pharmacy retailers Walgreens Boots Alliance (WBA) and CVS Health (CVS) may face some store closures and possible damage costs.