Communication about vaccination: A shared responsibility.

Vaccine hesitancy is an important issue to be addressed, due to the risk of decrease of vaccination coverage and consequent control of preventable diseases. While it is not considered a specific determinant, poor or inadequate communication can contribute to vaccine hesitancy and negatively influence vaccination uptake. As a contribution to the ongoing discussion regarding this theme and in the perspective of the implementation of the upcoming national vaccination plan in Italy, the Erice Declaration was drafted by experts in the field of immunization following a 5-day residential, independent workshop regarding communication topics in vaccinology. The aim of the current letter is to present to the broader international audience such a contribution, proposing the identification of the main actions that should be taken into account and prioritized in order to improve communication in the domain of vaccination.

Challenge with hepatitis B vaccine in children previously vaccinated with a hepatitis B-containing combination vaccine.

INTRODUCTION: The World Health Organization (WHO) recommends universal infant hepatitis B virus (HBV) vaccination as the most effective preventive measure against HBV-induced disease in endemic areas. More than 160 countries have followed the WHO recommendations to incorporate HBV vaccination in their national infant immunization programs. While antibodies to hepatitis B surface antigen (anti-HBs) concentrations progressively decrease following vaccination in infancy, protection persists, probably due to lasting immune memory. Hence, it is thought that future exposure to wild-type virus or HBV vaccine will induce a protective secondary immune response. METHODS: Children aged 7-8 years old who had been vaccinated in infancy with a hexavalent DTacP-IPV-HB-Hib vaccine (Hexavac(R); Sanofi Pasteur MSD, Lyon, France) and children aged 7-9 years vaccinated in infancy with a DT-HB vaccine (Primavax(R); Sanofi Pasteur MSD), whose anti-HBs concentrations had fallen below the seroprotective threshold of 10 mIU/mL at age 4.5-6 years, received a challenge dose of monovalent HBV vaccine (HBVAXPRO(R); Sanofi Pasteur MSD) to assess persistence of protection. RESULTS: One month postchallenge, 54 of 61 (88.5%) Hexavac-primed seronegative children and 34 of 40 (85.0%) Primavax-primed seronegative children had anti-HBs concentrations > or =10 mIU/mL. The percentage of protected children would have been even higher if the children who still had protective antibody levels (who were not included in this challenge study) had been assessed (42.1% with Hexavac, 55.4% with Primavax). CONCLUSION: Vaccination with a HBV-containing multivalent vaccine during infancy induces a lasting immune memory that can be boosted, even in children with a decline in anti-HBs concentrations. The present results confirm that the full primary vaccination schedule in infancy seems to confer long-term protection via immune memory and that an additional HBV dose is not generally required.

Safety, tolerability, and immunogenicity of a two-dose regimen of high-titer varicella vaccine in subjects > or =13 years of age.

A new manufacturing process, known as process upgrade varicella vaccine (PUVV) was developed for a refrigerated formulation of varicella vaccine and for an investigational zoster vaccine. Safety and tolerability of a two-dose regimen of high-titered (approximately 50,000 PFU) PUVV were compared to a lower-titer formulation (approximately 5400 PFU) of VARIVAX; in 1366 healthy subjects > or =13 years old. Only one vaccine-related clinical serious adverse experience (pruritus; no hospitalization) was reported, in the VARIVAX group. Injection-site adverse experiences following any dose were higher in the PUVV group, 70.0%, than in the VARIVAX group, 56.2%, but generally were mild. Immunogenicity were similar in both groups in seronegative subjects. PUVV was generally well tolerated, and elicited an immune response similar to that induced by the marketed formulation of VARIVAX.