Typhoid Immunization

1 December 9, 1994 / Vol. 43 / No. DEPARTMENT OF HEALTH AND HUMAN SERVICESP ublic Health ServiceCenters for Disease Controland Prevention (CDC)Atlanta, Georgia 30333 Typhoid ImmunizationRecommendations of the AdvisoryCommittee on Immunization Practices (ACIP)Copies can be purchased from Superintendent of Documents, GovernmentPrinting Office, Washington, DC 20402-9325. Telephone: (202) of trade names is for identification only and does not imply endorsement bythe Public Health Service or the Department of Health and Human MMWR series of publications is published by the Epidemiology Program Office,Centers for Disease Control and Prevention (CDC), Public Health Service, Depart-ment of Health and Human Services, Atlanta, GA for Disease Control and Prevention .. David Satcher, , The material in this report was prepared for publication by: National Center for Infectious James M. Hughes, Division of Bacterial and Mycotic Diseases .. Mitchell L.

2 Cohen, The production of this report as an MMWR serial publication was coordinated in: Epidemiology Program Stephen B. Thacker, , Richard A. Goodman, , , MMWR Series Scientific Information and Communications Program Recommendations and Suzanne M. Hewitt, Editor Rachel J. WilsonProject Editor Morie M. HigginsPeter M. JenkinsVisual Information Specialists SUGGESTED CITATIONC enters for Disease Control and Prevention. Typhoid Immunization recommen-dations of the Advisory Committee on Immunization Practices (ACIP). MMWR1994;43(No. RR-14):[inclusive page numbers].ContentsIntroduction ..1 Typhoid Vaccines ..1 Vaccine Usage ..2 Choice of Administration ..4 Adverse Reactions ..5 Precautions and Contraindications .. 43 / No. RR-14 MMWRiAdvisory Committee on Immunization PracticesMembership List, October 1994 CHAIRMANJ effrey P. Davis, Medical OfficerDepartment of Health and Social ServicesState of WisconsinMadison, WIACTING EXECUTIVE SECRETARYD ixie E.

3 Snider, , (Acting) Associate Director for ScienceCenters for Disease Control and Prevention (CDC)Atlanta, GAMEMBERSB arbara Ann DeBuono, Island Department of HealthProvidence, RIKathryn M. Edwards, University School of MedicineNashville, TNMarie R. Griffin, , University Medical CenterNashville, TNFernando A. Guerra, Antonio Metro Health DistrictSan Antonio, TXNeal A. Halsey, Hopkins University School of Hygiene and Public HealthBaltimore, MDRudolph E. Jackson, School of MedicineAtlanta, GAStephen C. Schoenbaum, Community Health Plan of New EnglandProvidence, RIFred E. Thompson, Jr., State Department of HealthJackson, MSJoel Ira Ward, Medical CenterTorrance, CAEX OFFICIO MEMBERSJohn La Montagne, Institutes of HealthBethesda, MDCarolyn Hardegree, and Drug AdministrationBethesda, MDJerry Zelinger, Care Financing AdministrationBaltimore, MDiiMMWRD ecember 9, 1994 Advisory Committee on Immunization PracticesMembership List, October 1994 ContinuedLIAISON REPRESENTATIVESA merican Academy of Family PhysiciansRichard Zimmerman, , PAAmerican Academy of PediatricsGeorges Peter, , RICaroline B.

4 Hall, , NYAmerican College of Obstetricians and GynecologistsStanley A. Gall, , KYAmerican College of PhysiciansPierce Gardner, , NYAmerican Hospital AssociationWilliam Schaffner, , TNAmerican Medical AssociationEdward A. Mortimer, Jr., , OHAssociation of Teachers of Preventive MedicineRichard D. Clover, , TXCanadian National Advisory Committee on Immunization (NACI)David Scheifele, , BCDepartment of DefenseWilliam M. Butler, , DCDepartment of Veterans AffairsKristin Lee Nichol, , , MNHospital Infections Control Practices Advisory CommitteeDavid W. Fleming, , ORInfectious Diseases Society of AmericaWilliam P. Glezen, , TXNational Vaccine Program(Acting) Chester RobinsonWashington, DCPharmaceutical Research and Manufacturers of AmericaThomas L. Copmann, , DCVol. 43 / No. RR-14 MMWRiiiThe following CDC staff members prepared this report:Paul R. Cieslak, MDRobert V. Tauxe, MD, MPHD ivision of Bacterial and Mycotic DiseasesNational Center for Infectious DiseasesJohn C.

5 Watson, MD, MPHE pidemiology and Surveillance DivisionNational Immunization Program Vol. 43 / No. RR-14 MMWRvTyphoid ImmunizationRecommendations of the Advisory Committee onImmunization Practices (ACIP)SummaryThese revised recommendations of the Advisory Committee on Immuniza-tion Practices update previous recommendations (MMWR 1990;39[RR-10]:1 5).They include information on the Vi capsular polysaccharide (ViCPS) vaccine,which was not available when the previous recommendations were incidence of Typhoid fever declined steadily in the United States from 1900 to1960 and has since remained low. From 1975 through 1984, the average number ofcases reported annually was 464. During that period, 57% of reported cases occurredamong persons 20 years of age; 62% of reported cases occurred among persons whohad traveled to other countries. From 1967 through 1976, only 33% of reported casesoccurred among travelers to other countries (1 ). Typhoid VACCINEST hree Typhoid vaccines are currently available for use in the United States: a) anoral live-attenuated vaccine (Vivotif Berna vaccine, manufactured from the Ty21astrain of Salmonella typhi (2 ) by the Swiss Serum and Vaccine Institute); b) a paren-teral heat-phenol-inactivated vaccine that has been widely used for many years( Typhoid Vaccine, manufactured by Wyeth-Ayerst); and c) a newly licensed capsularpolysaccharide vaccine for parenteral use (Typhim Vi, manufactured by PasteurM rieux).

6 A fourth vaccine, an acetone-inactivated parenteral vaccine, is currentlyavailable only to the armed no prospective, randomized trials comparing any of the three Typhoid vaccines have been conducted, several field trials have demon-strated the efficacy of each vaccine. In controlled field trials conducted amongschoolchildren in Chile, three doses of the Ty21a vaccine in enteric-coated capsulesadministered on alternate days reduced laboratory-confirmed infection by 66% over aperiod of 5 years (95% confidence interval [CI]=50% 77%) (3,4 ). In a subsequent trialin Chile, efficacy appeared to be lower: three doses resulted in only 33% (95% CI=0% 57%) fewer cases of laboratory-confirmed infection over a period of 3 years. When thedata were stratified by age in this trial, children 10 years of age had a 53% reductionin incidence of culture-confirmed Typhoid fever (95% CI=7% 77%), whereas children5 9 years of age had only a 17% reduction (95% CI=0% 53%).

7 This difference in age-related efficacy, however, is not statistically significant (5 ). In another trial in Chile, asignificant decrease in the incidence of clinical Typhoid fever occurred among personsreceiving four doses of vaccine compared with persons receiving two (p< ) orVol. 43 / No. RR-14 MMWR1three (p= ) doses. Because no placebo group was included in this trial, absolutevaccine efficacy could not be calculated (6 ).Weekly and triweekly dosing regimens have been less effective than alternate-daydosing (3 ). A liquid formulation of Ty21a is more effective than enteric-coated cap-sules (5,7,8 ), but only enteric-coated capsules are available in the United States. Theefficacy of vaccination with Ty21a has not been studied among persons from areaswithout endemic disease who travel to disease-endemic regions. The mechanism bywhich Ty21a vaccine confers protection is unknown; however, the vaccine does elicitboth serum (2,9 ) and intestinal (10 ) antibodies and cell-mediated immune responses(11 ).

8 Vaccine organisms can be shed transiently in the stool of vaccine recipients (2,9 ).However, secondary transmission of vaccine organisms has not been field trials involving a primary series of two doses of heat-phenol-inactivatedtyphoid vaccine (which is similar to the currently available parenteral inactivated vac-cine), vaccine efficacy over the 21 2- to 3-year follow-up periods ranged from 51% to77% (12 14 ). Efficacy for the acetone-inactivated parenteral vaccine, available only tothe armed forces, ranges from 75% to 94% (12,14,15 ).The newly licensed parenteral vaccine (Vi capsular polysaccharide [ViCPS]) is com-posed of purified Vi ( virulence ) antigen, the capsular polysaccharide elaborated byS. typhi isolated from blood cultures (16 ). In recent studies, one 25- g injection ofpurified ViCPS produced seroconversion ( , at least a fourfold rise in antibody titers)in 93% of healthy adults (17 ); similar results were observed in Europe (18 ).

9 Twofield trials in disease-endemic areas have demonstrated the efficacy of ViCPS in pre-venting Typhoid fever. In a trial in Nepal, in which vaccine recipients were observed for20 months, one dose of ViCPS among persons 5 44 years of age resulted in 74% (95%CI=49% 87%) fewer cases of Typhoid fever confirmed by blood culture than occurredwith controls (19 ). In a trial involving schoolchildren in South Africa who were 5 15years of age, one dose of ViCPS resulted in 55% (95% CI=30% 71%) fewer cases ofblood-culture-confirmed Typhoid fever over a period of 3 years than occurred withcontrols. The reduction in the number of cases in years 1, 2, and 3, was 61%, 52%, and50%, respectively (20,21 ). The efficacy of vaccination with ViCPS has not been studiedamong persons from areas without endemic disease who travel to disease-endemicregions or among children <5 years of age. ViCPS has not been tested among children<1 year of USAGER outine Typhoid vaccination is not recommended in the United States.

10 However,vaccination is indicated for the following groups: Travelers to areas in which there is a recognized risk of exposure to S. typhi. Risk isgreatest for travelers to developing countries ( , countries in Latin America, Asia,and Africa) who have prolonged exposure to potentially contaminated food anddrink (22 ). Multidrug-resistant strains of S. typhi have become common in someareas of the world ( , the Indian subcontinent [23 ] and the Arabian peninsula[24,25 ]), and cases of Typhoid fever that are treated with ineffective drugs can befatal. Travelers should be cautioned that Typhoid vaccination is not a substitute forcareful selection of food and drink. Typhoid vaccines are not 100% effective, andthe vaccine s protection can be overwhelmed by large inocula of S. typhi. 2 MMWRD ecember 9, 1994 Persons with intimate exposure ( , household contact) to a documented S. typhicarrier. Microbiology laboratorians who work frequently with S. typhi (26 ).