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Ahmed ST, Haider SS, Hanif S, Anwar HB, Mehjabeen S, Closser S, Bazant E, Sarker M. A scoping review on integrated health campaigns for immunization in low- and middle-income countries. Health Policy Plan 2023; 38:1198-1224. [PMID: 37699072 PMCID: PMC10752386 DOI: 10.1093/heapol/czad082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 07/19/2023] [Accepted: 09/01/2023] [Indexed: 09/14/2023] Open
Abstract
Health campaign integration is a key implementation strategy outlined by the World Health Organization to achieve universal health coverage. This scoping review synthesizes the evidence on Integrated Health Campaigns (IHC) in the field of immunization in low- and middle-income countries (LMICs) regarding the most common strategies, facilitators and barriers. Four reviewers followed a systematic approach to identify, screen and analyse relevant articles. The team used three search engines (PubMed, Scopus and Google Scholar) to identify peer-reviewed journal articles as well as select institutional websites for grey literature publications. Full-text articles using any study design and across any time frame were included. Data were extracted following a predefined matrix, analysed deductively and presented in a narrative synthesis. Thirty articles (20 academic and 10 grey) were included in the final review. All studies included identified IHCs as effective when planning or implementation is integrated. The common strategies were: using resources efficiently in remote locations; using national immunization days to maximize impact; targeting specific age groups by selecting intervention sites that are frequented by that age group; building community ownership over the integrated program; and integrating programs that already share common elements. The key facilitators were: closing the gap between services and communities; planning, coordination and resource management both before and during integration; cost-effectiveness; and utilization of pre-existing infrastructure. The common barriers included seemingly optimized initial cost to appear feasible only in the short term and additional responsibilities on the field staff. This review finds IHCs a common practice in immunization and identifies gaps in evidence on evaluation; indicating the need for additional research. Strong evidence accounts IHCs to increase coverage, improve community acceptance of health services and strengthen the community models of health service delivery.
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Affiliation(s)
- Syeda Tahmina Ahmed
- BRAC James P Grant School of Public Health, BRAC University, 6th Floor, Medona Tower, 28 Mohakhali Commercial Area, Bir Uttom A K Khandakar Road, Dhaka 1213, Bangladesh
| | - Shams Shabab Haider
- BRAC James P Grant School of Public Health, BRAC University, 6th Floor, Medona Tower, 28 Mohakhali Commercial Area, Bir Uttom A K Khandakar Road, Dhaka 1213, Bangladesh
| | - Suhi Hanif
- BRAC James P Grant School of Public Health, BRAC University, 6th Floor, Medona Tower, 28 Mohakhali Commercial Area, Bir Uttom A K Khandakar Road, Dhaka 1213, Bangladesh
| | - Humayra Binte Anwar
- BRAC James P Grant School of Public Health, BRAC University, 6th Floor, Medona Tower, 28 Mohakhali Commercial Area, Bir Uttom A K Khandakar Road, Dhaka 1213, Bangladesh
| | - Saima Mehjabeen
- BRAC James P Grant School of Public Health, BRAC University, 6th Floor, Medona Tower, 28 Mohakhali Commercial Area, Bir Uttom A K Khandakar Road, Dhaka 1213, Bangladesh
| | - Svea Closser
- John Hopkins University, Bultimore, Maryland 21218, US
| | - Eva Bazant
- The Task Force for Global Health, 330 W. Ponce de Leon Ave., Decatur, GA 30030, US
| | - Malabika Sarker
- BRAC James P Grant School of Public Health, BRAC University, 6th Floor, Medona Tower, 28 Mohakhali Commercial Area, Bir Uttom A K Khandakar Road, Dhaka 1213, Bangladesh
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Medise BE, Soedjatmiko S, Rengganis I, Gunardi H, Sekartini R, Koesno S, Satari HI, Hadinegoro SR, Yang JS, Excler JL, Sahastrabuddhe S, Puspita M, Sari RM, Bachtiar NS. Six-month follow up of a randomized clinical trial-phase I study in Indonesian adults and children: Safety and immunogenicity of Salmonella typhi polysaccharide-diphtheria toxoid (Vi-DT) conjugate vaccine. PLoS One 2019; 14:e0211784. [PMID: 30759132 PMCID: PMC6373931 DOI: 10.1371/journal.pone.0211784] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/30/2018] [Indexed: 11/19/2022] Open
Abstract
Introduction There is a high global incidence of typhoid fever, with an annual mortality rate of 200,000 deaths. Typhoid fever also affects younger children, particularly in resource-limited settings in endemic countries. Typhoid vaccination is an important prevention tool against typhoid fever. However, the available polysaccharide typhoid vaccines are not recommended for children under 2 years of age. A new typhoid conjugate Vi-diphtheria toxoid (Vi-DT) vaccine has been developed for infant immunization. We aimed to define the safety and immunogenicity of the Vi-DT vaccine among adults and children in Indonesia. Methods An observational, blinded, comparative, randomized, phase I safety study in two age de-escalating cohorts was conducted in East Jakarta, Indonesia, from April 2017 to February 2018. We enrolled 100 healthy subjects in 2 age groups: adults and children (18–40 and 2–5 years old). These groups were randomized into study groups (Vi-DT vaccine), and comparator groups (Vi-polysaccharide (Vi-PS) vaccine and another additional vaccine) which was administered in 4 weeks apart. Subjects were followed up to six months. Result One hundred healthy adults and children subjects completed the study. The Vi-DT and Vi-PS vaccines showed no difference in terms of intensity of any immediate local and systemic events within 30 minutes post-vaccination. Overall, pain was the most common local reaction, and muscle pain was the most common systemic reaction in the first 72 hours. No serious adverse events were deemed related to vaccine administration. The first and second doses of the Vi-DT vaccine induced seroconversion and higher geometric mean titers (GMT) in all subjects compared to that of baseline. However, in terms of GMT, the second dose of Vi-DT did not induce a booster response. Conclusion The Vi-DT vaccine is safe and immunogenic in adults and children older than two years. A single dose of the vaccine is able to produce seroconversion and high GMT in all individuals.
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Affiliation(s)
- Bernie Endyarni Medise
- Department of Child Health, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
- * E-mail:
| | - Soedjatmiko Soedjatmiko
- Department of Child Health, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
| | - Iris Rengganis
- Department of Internal Medicine, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
| | - Hartono Gunardi
- Department of Child Health, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
| | - Rini Sekartini
- Department of Child Health, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
| | - Sukamto Koesno
- Department of Internal Medicine, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
| | - Hindra Irawan Satari
- Department of Child Health, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
| | - Sri Rezeki Hadinegoro
- Department of Child Health, Faculty of Medicine Universitas Indonesia, Dr. Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia
| | - Jae Seung Yang
- International Vaccine Institute, Seoul, Republic of Korea
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Riddle M, Chen W, Kirkwood C, MacLennan C. Update on vaccines for enteric pathogens. Clin Microbiol Infect 2018; 24:1039-1045. [DOI: 10.1016/j.cmi.2018.06.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 12/12/2022]
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Date KA, Bentsi-Enchill A, Marks F, Fox K. Typhoid fever vaccination strategies. Vaccine 2015; 33 Suppl 3:C55-61. [PMID: 25902360 PMCID: PMC10644681 DOI: 10.1016/j.vaccine.2015.04.028] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 03/31/2015] [Accepted: 04/01/2015] [Indexed: 01/08/2023]
Abstract
Typhoid vaccination is an important component of typhoid fever prevention and control, and is recommended for public health programmatic use in both endemic and outbreak settings. We reviewed experiences with various vaccination strategies using the currently available typhoid vaccines (injectable Vi polysaccharide vaccine [ViPS], oral Ty21a vaccine, and injectable typhoid conjugate vaccine [TCV]). We assessed the rationale, acceptability, effectiveness, impact and implementation lessons of these strategies to inform effective typhoid vaccination strategies for the future. Vaccination strategies were categorized by vaccine disease control strategy (preemptive use for endemic disease or to prevent an outbreak, and reactive use for outbreak control) and vaccine delivery strategy (community-based routine, community-based campaign and school-based). Almost all public health typhoid vaccination programs used ViPS vaccine and have been in countries of Asia, with one example in the Pacific and one experience using the Ty21a vaccine in South America. All vaccination strategies were found to be acceptable, feasible and effective in the settings evaluated; evidence of impact, where available, was strongest in endemic settings and in the short- to medium-term. Vaccination was cost-effective in high-incidence but not low-incidence settings. Experience in disaster and outbreak settings remains limited. TCVs have recently become available and none are WHO-prequalified yet; no program experience with TCVs was found in published literature. Despite the demonstrated success of several typhoid vaccination strategies, typhoid vaccines remain underused. Implementation lessons should be applied to design optimal vaccination strategies using TCVs which have several anticipated advantages, such as potential for use in infant immunization programs and longer duration of protection, over the ViPS and Ty21a vaccines for typhoid prevention and control.
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Affiliation(s)
- Kashmira A Date
- Global Immunization Division, Centers for Disease Control and Prevention (CDC), Atlanta, GA 30329-4027, USA.
| | - Adwoa Bentsi-Enchill
- Department of Immunization, Vaccines and Biologicals (IVB), World Health Organization (WHO), Geneva, Switzerland
| | - Florian Marks
- International Vaccine Institute, Kwanak PO Box 14, Seoul 151-600, Republic of Korea
| | - Kimberley Fox
- World Health Organization Regional Office for the Western Pacific, United Nations Avenue, 1000 Manila, Philippines
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Typhoid vaccine introduction: An evidence-based pilot implementation project in Nepal and Pakistan. Vaccine 2015; 33 Suppl 3:C62-7. [DOI: 10.1016/j.vaccine.2015.03.087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 03/15/2015] [Accepted: 03/16/2015] [Indexed: 11/21/2022]
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Khan MI, Ochiai RL, Clemens JD. Population impact of Vi capsular polysaccharide vaccine. Expert Rev Vaccines 2014; 9:485-96. [DOI: 10.1586/erv.10.43] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Bajracharya D, Khan MI, Pach A, Shrestha P, Joshi N, Upreti SR, Wierzba T, Puri M, Sahastrabuddhe S, Ochiai RL. 25 years after Vi typhoid vaccine efficacy study, typhoid affects significant number of population in Nepal. PLoS One 2014; 9:e77974. [PMID: 24400067 PMCID: PMC3882213 DOI: 10.1371/journal.pone.0077974] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 09/08/2013] [Indexed: 11/19/2022] Open
Abstract
Salmonella Typhi, first isolated in 1884, results in infection of the intestines and can end in death and disability. Due to serious adverse events post vaccination, whole cell killed vaccines have been replaced with new generation vaccines. The efficacy of Vi polysaccharide (ViPS) vaccine, a new generation, single-dose intramuscular typhoid vaccine was assessed in Nepal in 1987. However, despite the availability of ViPS vaccine for more than 25 years, Nepal has one of the highest incidence of typhoid fever. Therefore we collected information from hospitals in the Kathmandu Valley from over the past five years. There were 9901 enteric fever cases between January 2008 and July 2012. 1,881 of these were confirmed typhoid cases from five hospitals in the Kathmandu district. Approximately 70% of the cases involved children under 15 years old. 1281 cases were confirmed as S. Paratyphi. Vaccines should be prioritized for control of typhoid in conjunction with improved water and sanitation conditions in Nepal and in endemic countries of Asia and Africa.
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Affiliation(s)
- Deepak Bajracharya
- MITRA Samaj Pani Pokhari, Kathmandu, Nepal
- Group for Technical Assistance, Sanepa, Nepal
| | - M. Imran Khan
- International Vaccine Institute, Seoul, South Korea
- * E-mail:
| | - Alfred Pach
- International Vaccine Institute, Seoul, South Korea
| | | | | | - Shyam R. Upreti
- Child Health Division, Department of Health Services, Ministry of Health and Population, Kathmandu, Nepal
| | | | - Mahesh Puri
- International Vaccine Institute, Seoul, South Korea
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Abstract
PURPOSE OF REVIEW Strains of Salmonella enterica subsp. enterica are amongst the most commonly identified invasive bacterial pathogens in resource-poor settings, and cause significant mortality, particularly in children. In this study we review recent progress in the development of vaccines against S. Typhi, S. Paratyphi and nontyphoidal Salmonella for children. RECENT FINDINGS Typhoid remains common and S. Paratyphi A is increasingly recognized as a cause of enteric fever in Asia. In rural Africa, nontyphoidal salmonellae are among the most common invasive bacterial infections, although S. Typhi predominates in some urban centres. Licensed vaccines against typhoid have moderate but useful efficacy but neither of the two available vaccines can be used in infants. Although Ty21a may afford some cross-protection against S. Paratyphi B, there are no vaccines that specifically target paratyphoid or any nontyphoidal Salmonella. Several live attenuated vaccines are under development and may offer some advantages over Ty21a. Vi-conjugate vaccines should offer children excellent protection from typhoid once licensed. SUMMARY There are few effective vaccines against Salmonella sp. and those that do exist target only one serovar, S. Typhi. Research is urgently needed to combat emerging agents of enteric fever such as S. Paratyphi A as well as nontyphoidal serovars, which commonly cause invasive disease in Africa.
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Public acceptance and willingness-to-pay for a future dengue vaccine: a community-based survey in Bandung, Indonesia. PLoS Negl Trop Dis 2013; 7:e2427. [PMID: 24069482 PMCID: PMC3777870 DOI: 10.1371/journal.pntd.0002427] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 08/02/2013] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND All four serotypes of dengue virus are endemic in Indonesia, where the population at risk for infection exceeds 200 million people. Despite continuous control efforts that were initiated more than four decades ago, Indonesia still suffers from multi-annual cycles of dengue outbreak and dengue remains as a major public health problem. Dengue vaccines have been viewed as a promising solution for controlling dengue in Indonesia, but thus far its potential acceptability has not been assessed. METHODOLOGY/PRINCIPAL FINDINGS We conducted a household survey in the city of Bandung, Indonesia by administering a questionnaire to examine (i) acceptance of a hypothetical pediatric dengue vaccine; (ii) participant's willingness-to-pay (WTP) for the vaccine, had it not been provided for free; and (iii) whether people think vector control would be unnecessary if the vaccine was available. A proportional odds model and an interval regression model were employed to identify determinants of acceptance and WTP, respectively. We demonstrated that out of 500 heads of household being interviewed, 94.2% would agree to vaccinate their children with the vaccine. Of all participants, 94.6% were willing to pay for the vaccine with a median WTP of US$1.94. In addition, 7.2% stated that vector control would not be necessary had there been a dengue vaccination program. CONCLUSIONS/SIGNIFICANCE Our results suggest that future dengue vaccines can have a very high uptake even when delivered through the private market. This, however, can be influenced by vaccine characteristics and price. In addition, reduction in community vector control efforts may be observed following vaccine introduction but its potential impact in the transmission of dengue and other vector-borne diseases requires further study.
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Abstract
PURPOSE OF REVIEW This review summarizes the recent advances in vaccination against Salmonella enterica serovar Typhi and highlights the data supporting the development of next generation vaccines to address paratyphoid fever and invasive nontyphoidal Salmonella (iNTS) disease. RECENT FINDINGS There has been increasing awareness of the disease burden caused by S. Typhi particularly in Africa and greater recognition of S. Paratyphi A's contribution to enteric fever episodes throughout Asia. Groups have been working to improve the existing typhoid vaccines and provide comprehensive data on the feasibility of their implementation in endemic settings. These data have resulted in modifications to the recommendations for typhoid vaccination in traveller markets and endemic settings, and has also led to the development of S. Paratyphi A vaccine components that can be combined with existing typhoid vaccines to generate bivalent formulations against enteric fever. The epidemiology of iNTS serovars as cause of appreciable morbidity and mortality in Africa, and the need for vaccines, has also become more widely appreciated. SUMMARY Current typhoid vaccines, although moderately effective for short periods of time, cannot be used in all age groups and only target one of the clinically relevant Salmonella serovars. Greater effort must be placed on the development and implementation of improved vaccines for the disease burden resulting from Typhi, Paratyphi A or iNTS infections.
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Hyde TB, Dentz H, Wang SA, Burchett HE, Mounier-Jack S, Mantel CF. The impact of new vaccine introduction on immunization and health systems: a review of the published literature. Vaccine 2012; 30:6347-58. [PMID: 22940378 DOI: 10.1016/j.vaccine.2012.08.029] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 07/31/2012] [Accepted: 08/15/2012] [Indexed: 02/05/2023]
Abstract
We conducted a systematic review of the published literature to examine the impact of new vaccine introduction on countries' immunization and broader health systems. Six publication databases were searched using 104 vaccine and health system-related search terms. The search yielded 15,795 unique articles dating from December 31, 1911 to September 29, 2010. Based on review of the title and abstract, 654 (4%) of these articles were found to be potentially relevant and were referred for full review. After full review, 130 articles were found to be relevant and included in the analysis. These articles represented vaccines introduced to protect against 10 different diseases (hepatitis A, hepatitis B, Haemophilus influenzae type b disease, human papilloma virus infection, influenza, Japanese encephalitis, meningococcal meningitis, Streptococcus pneumoniae disease, rotavirus diarrhea and typhoid), in various formulations and combinations. Most reviewed articles (97 [75%]) reported experiences in high-income countries. New vaccine introduction was most efficient when the vaccine was introduced into an existing delivery platform and when introduced in combination with a vaccine already in the routine childhood immunization schedule (i.e., as a combination vaccine). New vaccine introduction did not impact coverage of vaccines already included in the routine childhood immunization schedule. The need for increased cold chain capacity was frequently reported. New vaccines facilitated the introduction and widespread use of auto-disable syringes into the immunization and the broader health systems. The importance of training and education for health care workers and social mobilization was frequently noted. There was evidence in high-income countries that new vaccine introduction was associated with reduced health-care costs. Future evaluations of new vaccine introductions should include the systematic and objective assessment of the impacts on a country's immunization system and broader health system, especially in lower-income countries.
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Affiliation(s)
- Terri B Hyde
- Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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Effectiveness of Vi capsular polysaccharide typhoid vaccine among children: A cluster randomized trial in Karachi, Pakistan. Vaccine 2012; 30:5389-95. [DOI: 10.1016/j.vaccine.2012.06.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 06/06/2012] [Accepted: 06/06/2012] [Indexed: 11/19/2022]
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Penny M, Bartolini R, Mosqueira NR, LaMontagne DS, Mendoza MA, Ramos I, Winkler JL, Villafana J, Janmohamed A, Jumaan AO. Strategies to vaccinate against cancer of the cervix: Feasibility of a school-based HPV vaccination program in Peru. Vaccine 2011; 29:5022-30. [DOI: 10.1016/j.vaccine.2011.04.078] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 04/05/2011] [Accepted: 04/21/2011] [Indexed: 01/05/2023]
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Karki S, Kumar K. Study on the possible use of Vi polysaccharide typhoid fever vaccine to control endemic typhoid fever in Nepal. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2011. [DOI: 10.1016/s2222-1808(11)60019-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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New advances in typhoid Fever vaccination strategies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 697:17-39. [PMID: 21120717 DOI: 10.1007/978-1-4419-7185-2_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Sur D, Ochiai RL, Bhattacharya SK, Ganguly NK, Ali M, Manna B, Dutta S, Donner A, Kanungo S, Park JK, Puri MK, Kim DR, Dutta D, Bhaduri B, Acosta CJ, Clemens JD. A cluster-randomized effectiveness trial of Vi typhoid vaccine in India. N Engl J Med 2009; 361:335-44. [PMID: 19625715 DOI: 10.1056/nejmoa0807521] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Typhoid fever remains an important cause of illness and death in the developing world. Uncertainties about the protective effect of Vi polysaccharide vaccine in children under the age of 5 years and about the vaccine's effect under programmatic conditions have inhibited its use in developing countries. METHODS We conducted a phase 4 effectiveness trial in which slum-dwelling residents of Kolkata, India, who were 2 years of age or older were randomly assigned to receive a single dose of either Vi vaccine or inactivated hepatitis A vaccine, according to geographic clusters, with 40 clusters in each study group. The subjects were then followed for 2 years. RESULTS A total of 37,673 subjects received a dose of a study vaccine. The mean rate of vaccine coverage was 61% for the Vi vaccine clusters and 60% for the hepatitis A vaccine clusters. Typhoid fever was diagnosed in 96 subjects in the hepatitis A vaccine group, as compared with 34 in the Vi vaccine group, with no subject having more than one episode. The level of protective effectiveness for the Vi vaccine was 61% (95% confidence interval [CI], 41 to 75; P<0.001 for the comparison with the hepatitis A vaccine group). Children who were vaccinated between the ages of 2 and 5 years had a level of protection of 80% (95% CI, 53 to 91). Among unvaccinated members of the Vi vaccine clusters, the level of protection was 44% (95% CI, 2 to 69). The overall level of protection among all residents of Vi vaccine clusters was 57% (95% CI, 37 to 71). No serious adverse events that were attributed to either vaccine were observed during the month after vaccination. CONCLUSIONS The Vi vaccine was effective in young children and protected unvaccinated neighbors of Vi vaccinees. The potential for combined direct and indirect protection by Vi vaccine should be considered in future deliberations about introducing this vaccine in areas where typhoid fever is endemic. (ClinicalTrials.gov number, NCT00125008.)
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Affiliation(s)
- Dipika Sur
- National Institute of Cholera and Enteric Diseases, Kolkata, India
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Whitaker JA, Franco-Paredes C, del Rio C, Edupuganti S. Rethinking typhoid fever vaccines: implications for travelers and people living in highly endemic areas. J Travel Med 2009; 16:46-52. [PMID: 19192128 DOI: 10.1111/j.1708-8305.2008.00273.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jennifer A Whitaker
- Department of Medicine, Division of Infectious Disease, Emory University School of Medicine, Atlanta, GA, USA
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