Lessons and implications from a mass immunization campaign in squatter settlements of Karachi, Pakistan: An experience from a cluster-randomized double-blinded vaccine trial [NCT00125047]

Mohammad Imran Khan, Rion Leon Ochiai, Hasan Bin Hamzal, Shah Muhammad Sahito, Muhammad Atif Habib, Sajid Bashir Soofi, Naveed Sarwar Bhutto, Shahid Rasool, Mahesh K. Puri, Mohammad Ali, Shafi Mohammad Wasan, Mohammad Jawed Khan, Remon Abu-Elyazeed, Bernard Ivanoff, Claudia M. Galindo, Tikki Pang, Allan Donner, Lorenz Von Seidlein, Camilo J. Acosta, John D. ClemensShaikh Qamaruddin Nizami, Zulfiqar A. Bhutta

Research output: Contribution to journalArticle

Abstract

Objective: To determine the safety and logistic feasibility of a mass immunization strategy outside the local immunization program in the pediatric population of urban squatter settlements in Karachi, Pakistan. Methods: A cluster-randomized double blind preventive trial was launched in August 2003 in 60 geographic clusters covering 21,059 children ages 2 to 16 years. After consent was obtained from parents or guardians, eligible children were immunized parenterally at vaccination posts in each cluster with Vi polysaccharide or hepatitis A vaccine. Safety, logistics, and standards were monitored and documented. Results: The vaccine coverage of the population was 74% and was higher in those under age 10 years. No life-threatening serious adverse events were reported. Adverse events occurred in less than 1% of all vaccine recipients and the main reactions reported were fever and local pain. The proportion of adverse events in Vi polysaccharide and hepatitis A recipients will not be known until the end of the trial when the code is broken. Throughout the vaccination campaign safe injection practices were maintained and the cold chain was not interrupted. Mass vaccination in slums had good acceptance. Because populations in such areas are highly mobile, settlement conditions could affect coverage. Systemic reactions were uncommon and local reactions were mild and transient. Close community involvement was pivotal for information dissemination and immunization coverage. Conclusion: This vaccine strategy described together with other information that will soon be available in the area (cost/effectiveness, vaccine delivery costs, etc) will make typhoid fever control become a reality in the near future.

Original languageEnglish (US)
Article number17
JournalTrials
Volume7
DOIs
StatePublished - May 25 2006

    Fingerprint

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Pharmacology (medical)

Cite this

Khan, M. I., Ochiai, R. L., Hamzal, H. B., Sahito, S. M., Habib, M. A., Soofi, S. B., Bhutto, N. S., Rasool, S., Puri, M. K., Ali, M., Wasan, S. M., Khan, M. J., Abu-Elyazeed, R., Ivanoff, B., Galindo, C. M., Pang, T., Donner, A., Von Seidlein, L., Acosta, C. J., ... Bhutta, Z. A. (2006). Lessons and implications from a mass immunization campaign in squatter settlements of Karachi, Pakistan: An experience from a cluster-randomized double-blinded vaccine trial [NCT00125047]. Trials, 7, [17]. https://doi.org/10.1186/1745-6215-7-17