In 2013, Merck recalled one batch of Gardasil, a human papillomavirus (HPV) vaccine. The recall was a precaution following an error in the manufacturing process. The company had concerns that a small number of vials might have contained glass particles due to breakage. No health problems were reported relating to this recall other than known side effects that can result from any vaccination, like arm redness and soreness where the shot was given.