Prevention of Shingles: The Zostavax Vaccine
Dr. Patel is a clinical assistant professor in the Department of Pharmacy Practice, Oregon State University/ Oregon Health & Science University, College of Pharmacy, Portland campus.
The same virus that causes chickenpoxcauses herpes zoster,commonly known as shingles.Herpes zoster is caused by the reactivationof the varicella-zoster virus (VZV)from latency after infection with chickenpox.After an episode of chickenpox, thevirus becomes dormant in the body andcan reappear many years later to causea case of shingles.
The annual incidence of herpes zosterranges from approximately 1.5 to 4.0cases per 1000 persons.1,2 The cause ofthe VZV reactivation is unclear.3,4 However,increasing age, altered cell immunity, andimmunocompromised state (such as withHIV infection) are risk factors for the developmentof herpes zoster.1,3,4Herpes zoster is an acute, localizedinfection that causes a painful, blisteringrash. A shingles rash usually appears on1 side of the face or body and lasts for 2to 4 weeks.2 Symptoms include pain or aburning sensation in specific parts of thebody, headaches, upset stomach, andchills. The typical rash appears in 2 to 3days, after the virus has reached the skin.It consists of red patches of skin blisters(vesicles) that look very similar to earlychickenpox.5 The rash progresses toclusters of clear vesicles, which continueto form for 3 to 5 days and evolvethrough stages of pustulation, ulceration,and crusting.3 The crusts fall off in 2 to 3weeks, leaving behind pink healing skin.
Shingles can be contagious throughdirect contact in an individual who hasnot had chickenpox. Shingles is a reactivationof the VZV virus, and this conditionis not spread through sneezing, coughing,or casual contact. Anyone who hasrecovered from chickenpox may developshingles. Shingles is more common, however,in people aged 50 and older, peoplewho have medical conditions that keepthe immune system from working properly,or people who receive immunosuppressivedrugs.
Treatment for shingles includes antiviraldrug therapy to accelerate the healingof the skin lesions (Table3).
Pain medications and steroids may beadded for symptomatic relief and toreduce inflammation. Nondrug therapyto reduce the risk of infection mayinclude keeping the lesions clean and drywith soap and water, applying compresses(water, saline, Burow?s solution), andwearing loose-fitting clothing forimproved comfort.
Extreme pain and shingles infectioncan lead to pneumonia, hearing problems,blindness, brain inflammation(encephalitis), or death. Postherpeticneuralgia is a persistent pain syndromethat occurs after resolution of rash and isthe most debilitating complication of herpeszoster. Both the incidence and theduration of postherpetic neuralgia aredirectly correlated with the patient?sage.3 Pain can persist for months andoccasionally years.Prevention
If patients have not had chickenpox orreceived the chickenpox vaccine, theyshould be advised to avoid contact withthe skin lesions of persons with knownherpes zoster infection (shingles orchickenpox), especially if they areimmunocompromised.
The chickenpox (varicella) vaccine is arecommended childhood vaccine, and italso can be administered to adults whohave never had chickenpox. Two varicellavirus?containing vaccines are currentlylicensed for use in the United States.Varivax is the single-antigen varicella vaccine,and ProQuad, or MMRV, is a combinationvaccine of measles, mumps,rubella, and varicella. Due to the increasein cell-mediated immunity in older adults,however, a higher titer of live attenuatedvirus is required. As a result, herpeszoster can now be prevented with a newVZV vaccine.Herpes Zoster VaccineThe FDA approved the first live VZVvaccine, called Zostavax (Oka/Merck) onMay 25, 2006, to reduce the risk of shinglesfor use in people 60 years of age and older.6The preventive effect of zoster vaccine isthought to be a consequence of itsboosting effect on VZV-specific immunity.Each 0.65-mL single-dose vaccine contains19,400 plaque-forming units ofvirus, considerably more than the ~1350plaque-forming units found in the vaccineto prevent varicella in children. OnOctober 25, 2006, the Advisory Committeeon Immunization Practices (ACIP)voted to recommend a single dose ofzoster vaccine for adults aged 60 yearsand older, whether or not they report aprior episode of herpes zoster.8 Furthermore,persons with chronic medicalconditions may be vaccinated unless acontraindication or precaution exists fortheir condition.8
A large efficacy study by the ShinglesPrevention Study Group evaluated thehigh-titer, live attenuated zoster vaccine.This was a placebo-controlled double-blindtrial in which 38,546 subjects aged60 and older were randomized to receivea single dose of either Zostavax or placebo.The participants were followed forthe development of zoster for a medianof 3.1 years. This study excluded peoplewho were immunocompromised orusing corticosteroids on a regular basisand anyone with a previous history ofherpes zoster.
The use of the zoster vaccine reducedthe burden of illness due to herpeszoster by 61.1%, reduced the incidenceof postherpetic neuralgia by 66.5%, andreduced the incidence of herpes zosterby 51.3%.9 The vaccine was more efficaciousin preventing herpes zoster amongpersons aged 60 to 69 than among those70 and older.9 The vaccine did preventpostherpetic neuralgia to a greaterextent, however, among those aged 70and older than among those aged 60 to69.9 This study concluded that the vaccinemarkedly reduced morbidity fromherpes zoster and postherpetic neuralgiaamong older adults.9
Zostavax is not indicated for the treatmentof zoster or postherpetic neuralgia.It should not be used in children, and it isnot a substitute for Varivax (chickenpoxvaccine). Zostavax should not be used bywomen who are or may be pregnant andpeople who are allergic to neomycin orgelatin. People with a history of immunodeficiencyconditions or those receivingimmunosuppressive therapy, includingcorticosteroids, and active tuberculosisshould not receive the vaccine.
Zostavax is administered subcutaneouslyas a single dose in the upperarm. The vaccine is stored frozen andshould be reconstituted using only thediluents supplied. It should be administeredimmediately after reconstitutionand discarded if not used within 30 minutes.It is supplied as a package of 1 single-dose vial or 10 single-dose vials oflyophilized vaccine and diluents.
Some common side effects reportedwere headache and redness, pain andtenderness, itching, and swelling at theinjection site. Adequate treatment provisions,including epinephrine injection,should be available for immediate use,should an anaphylactic reaction occur.Conclusion
Now that the vaccine is available,patients who are 60 years of age and older should beadvised about immunization. For thosewho develop shingles, it is important toprovide education on what to expect.Patients should be educated both onhow to manage the chronic pain andabout the potential infection risk to others.Health care workers should beadvised to use standard precautions andgloves when examining lesions.
Herpes zoster can occur in anyonewho has had varicella. The vaccine giveshealth care providers an important toolthat can help prevent an illness thataffects many older Americans.
It is anticipated that zoster vaccine willnot be covered under Medicare Part B.10The vaccine instead will be reimbursedthrough the Medicare Part D program.10Beneficiaries should contact their Part Dplan for more information.Studies have concluded that the vaccinewould increase quality-adjusted lifeyears,compared with no vaccination.4,11An ongoing analysis of cost-effectivenessand efficacy in those for whom the vaccineis not indicated needs to be evaluated.This evaluation will probably influencefuture recommendations for herpeszoster immunizations.Immunizations for the elderly are crucial,and health care professionals needto be informed on recent changes oradditions to recommendations made bythe ACIP. New vaccines are on the horizonfor various conditions such as genitalherpes, HIV/AIDS, human papillomavirus,Alzheimer?s disease, cancer, the commoncold, malaria, and many more. Forupdated information, visit the Centers forDisease Control and Prevention Web siteat www.cdc.gov.References
1. Donahue JG, Choo PW, Manson JE, Platt R. The incidence of herpes zoster. Arch Intern Med. 1995;155:1605-1609.
2. Advisory Committee on Immunization Practices. Considerations for shingles vaccine recommendations in the US: record of the proceedings. Atlanta, Ga: Centers for Disease Control and Prevention; 2006. Available at: http://cdc.gov/nip/acip. Accessed June 13, 2007.
3. Gnann JW Jr, Whitley RJ. Clinical practice: herpes zoster. New Engl J Med. 2002;347 (5):340-346.
4. Kimberlin DW, Whitley RJ. Varicella-zoster vaccine for the prevention of herpes zoster. New Engl J Med. 2007;356(13):1338-1343.
5. National Institute of Health Medline Plus. Herpes Zoster. Available at: www.nih.gov/. Accessed June 13, 2007.
6. US Food and Drug Administration. FDA licenses new vaccine to reduce older American?s risk of shingles. Available at: www.fda.gov. Accessed June 13, 2007.
7. Zostavax package insert. Available at: www.fda.gov/cber/label/zosmer052506pi.pdf. Accessed June 13, 2007.
8. CDC. ACIP provisional recommendations for the use of zoster vaccine. Available at: www.cdc.gov/vaccines/recs/provisional/downloads/zoster-11-20-06.pdf. Accessed June 13, 2007.
9. Oxman MN, Levin MJ, Johnson GR, et al. A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults. N Eng J Med. 2005;352:2271-2284.
10. CDC. National Immunization Program (NIP). Herpes Zoster Vaccine (Shingles). Available at: www.cdc.gov/nip/vaccine/zoster/faqs-vacc-zoster.htm. Accessed June 13, 2007.
11. Hornberger J, Robertus K. Cost-effectiveness of a vaccine to prevent herpes zoster and postherpetic neuralgia in older adults. Ann Intern Med. 2006;145:317-325.