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In the pediatric population, will administration of the varicella vaccine, as opposed to a child having chickenpox, increase a child’s long-term immunity to the varicella zoster virus? Background • • • CDC licensed VZV vaccine in 1995 The virus is known to enter through the respiratory tract and conjunctiva, where it then enters the bloodstream and replicates and produces visible symptoms in between 10 to 21 days. The primary symptoms are pruritic vesicles and fever. Although the virus is usually selflimiting and not life-threatening, it almost always causes loss of productivity in school or the workplace, and serious complications can occasionally occur. CDC VZV Vaccine Guidelines • Vaccine is given subcutaneously in 2 doses, administered at least 3 months apart a. Dose 1 at 12-15 months of age b. Dose 2 at 4-6 years of age Pertinent Studies • • • • • • Results and recommendations from the CDC have been gathered through surveillance programs by participating states. After receiving the vaccine as a single dose, the instance of developing an infection from the VZV among school aged children did decrease. A second dose of the vaccine was added to the regimen, and the reported instances in children continued to decrease. The second dose is given to ensure that infants and children who have a primary vaccine failure or a limited initial immune response have more complete and persisting protection. The efficacy of the VZV is 97% after the initial vaccination and 99% after the second dose. When a patient does experience a breakthrough, it has been reported to have a less severe course for individuals who have had the vaccination. • The disease is milder in 70% of individuals with less than 50 lesions on their skin in those experiencing breakthrough post-vaccination. Regardless of vaccination, exposure to a variant strain can still produce chickenpox in a person’s life. Conclusion • Other recommended vaccinations have proven over time to decrease sickness, productivity loss, and mortality and morbidity. • By adhering to the CDC recommendations, mass immunity can lead to decreased prevalence of and infections from the VZV, therefore decreasing loss of productivity and serious complications. • Evidence has been found that immunocompromised children receiving antiretroviral therapy who received the varicella vaccine were better protected against HZ than those children who had not received vaccination. • Administration of a second dose and higher titers have demonstrated additional protection against both chickenpox and long-term prevention of developing a reactivation and subsequently shingles. • Immunity to zoster infection by those naturally infected is likely multivariable and is more a function of an individual’s immune system. • The vaccine has been used for less than 20 years on a large-scale in the US, and those vaccinated have not progressed far enough into adulthood where herpes zoster is a common occurrence, which makes a significant statistical determination to if the vaccine is superior in preventing future outbreaks of shingles compared to natural infection not possible. Contraindications • • • • • • Cancer or immunocompromised (HIV) On immunosuppressive drugs or radiation treatment Suffering from an acute illness Pregnant women, or women planning on becoming pregnant Allergic Reaction to any component of the vaccine, or a previous administration Received blood products in the previous 11 months References Adolescent female with varicella lesions in various stages. (2009). Retrieved December 7, 2012, from http://www.vaccineinformation.org/varicel/photos.asp. Varicella-Zoster Virus in the Skin [Chickenpox]. (2010). Retrieved November 24, 2012, from http://viraldiseasesc.wikispaces.com/Chickenpox Center for Disease Control and Prevention. (2012). Vaccines and Immunizations: Varicella. Retrieved from http://www.cdc.gov/vaccines/pubs/pinkbook/varicella.html Evolution of Varicella Surveillance - Selected States, 2000-2010. Morbidity and Mortality Weekly Report. Retrieved from www.cdc.gov. Goldman, G.S., King, P.G. (Article In Press). Review of the United States universal varicella vaccination program: Herpes zoster incidence rates, cost-effectiveness, and vaccine efficacy based primarily on the Antelope Valley Varicella Active Surveillance Project data. Vaccine. Retrieved from www.pubmed.com Pasquariello, P.S., Hessen, M.T. (2012). Immunizations in Children. Advisory Committee on Immunization Practices, MMWR Morb Mortal Wkly Rep. 60:1391-2. Retrieved from http://www.mdconsult.com/das/pdxmd/body/3842224604/1382824524?type=med&eid=9-u1.0-_1_mt_6060101 Brisson, M., Edmunds, W.J., Gay, N.J. (2003). Varicella vaccination: impact of vaccine efficacy on the epidemiology of VZV. Journal of Virology, 70 Suppl 1:S31-7. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/12627484 Bloch, Karen C., Johnson, James C. (2012). Varicella Zoster Virus Transmission in the Vaccine Era: Unmasking the Role of Herpes Zoster. The Journal of Infectious Diseases, 205(9), 1336-41. 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