Future vaccines in Iran: Varicella, Hepatitis A

Vaccination has been instrumental in controlling Hepatitis A and Varicella infections. Hepatitis A vaccines, licensed in the United States since ۱۹۹۵, include single-antigen vaccines (Havrix and Vaqta) and a combined HepA-HepB vaccine (Twinrix). These vaccines are administered intramuscularly in a ۲-dose or ۳-dose series, depending on the formulation and age group. Vaccination is recommended for all children beginning at ۱۲ months and for adults at increased risk, including travellers to endemic areas, persons experiencing homelessness, and people with chronic liver disease or HIV. HepA vaccines demonstrate high immunogenicity, with over ۹۵% adults and ۹۷% children developing protective antibodies after the first dose, and nearly ۱۰۰% seroconversion after completion. Protective antibodies may persist for decades. Postexposure prophylaxis is available with HepA vaccine and immune globulin (IG), especially for high-risk individuals. Varicella vaccination in the United States began in ۱۹۹۵ with live attenuated vaccines: VAR (Varivax) and MMRV (ProQuad), the latter combining measles, mumps, rubella, and varicella antigens. The ۲-dose varicella vaccination schedule starts at ۱۲-۱۵ months with a booster at ۴-۶ years. Varicella vaccines are highly effective, achieving ۸۲% effectiveness after one dose and ۹۲% after two doses, significantly reducing morbidity and mortality. Postexposure vaccination is effective if administered within ۳ to ۵ days after exposure. Vaccination is contraindicated in severely immunocompromised individuals and pregnant women. Overall, these vaccination programs have substantially decreased disease incidence and complications in the U.S. population. In conclusion, the widespread use of vaccines for Hepatitis A and varicella has dramatically reduce the incidence, morbidity, and mortality associated with these diseases in Iran. Both vaccines demonstrate high immunogenicity and long-lasting protection, with established safety profiles across different populations, including children, adults, and pregnant women. Continued efforts in vaccination coverage, targeted immunization of high-risk groups, and appropriate postexposure prophylaxis remain essential to control and prevent outbreaks, ultimately advancing toward the elimination of these vaccine-preventable infections. In this presentation, we review the necessity and the importance of Varicella and Hepatitis A vaccination in Iran.