Safety and perception: What are the greatest enemies of HPV vaccination programmes?

Vaccines stimulate a person's immune system to produce an adequate reaction against a specific infectious agent; i.e. the person is protected from that disease without having to get it first. As vaccines are administrated to healthy subjects, they are held to the highest standards of safety. Regarding human papillomavirus (HPV) vaccines, at present three prophylactic vaccines are licensed (bivalent HPV 16/18, quadrivalent HPV 6/11/16/18 and the nonovalent HPV 6/11/16/18/31/33/45/52/58 vaccine). Pre- and post-licensure studies (i.e. not yet for nonovalent HPV vaccine) confirm that HPV vaccines are generally safe and well-tolerated, site injections symptoms are the most common adverse events (AEs) reported, and pain is the most frequently referred local symptom. Serious AEs are rare and not associated with severe sequelae, at least no vaccine-related deaths have occurred. Despite these scientific evidences, it is still difficult to explain to the population the importance of a good vaccination programme. There are many determinants for HPV vaccines hesitancy which represent a barrier that must be overcome in order to increase vaccine coverage, including psychological reactions, religious or cultural aspects, and fear of possible AEs (demyelinating diseases, Complex Regional Pain Syndrome - CRPS, or Postural Orthostatic Tachycardia Syndrome - POTS). A weak communication strategy which frequently suffers due to spread of unverified news by media and websites may lead to the failure of a vaccination programme. Such a situation happened in Japan (2013), due to which a great number of women remain vulnerable to HPV-related cancers. In order to resolve the issues around HPV vaccines acceptance, it is necessary to use good communication strategies. Multicomponent and dialogue-based interventions seem to be the most effective, especially if an adequate language is used, customized according to the vaccination programme target.