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ABSTRACT: Since 1997, when the goal of interrupting measles transmission by 2010 was adopted, substantial progress has been made toward the elimination of measles in the Eastern Mediterranean Region (EMR). For the 22 EMR member countries, routine coverage with the first dose of a measles-containing vaccine (MCV) increased from 70% in 1997 to 82% in 2009. All 22 countries conducted measles catch-up vaccination campaigns during 1994-2009, and most conducted follow-up campaigns as needed. Of the 22 EMR countries, 19 have established case-based surveillance for measles with laboratory confirmation. Reported measles cases decreased by 86% during 1998-2008, and estimated measles mortality decreased by 93% during 2000-2008, accounting for 17% of global measles mortality reduction during that period. Despite these successes, several significant challenges remain, and the EMR will not be able to achieve measles elimination by the end of 2010. Achieving and maintaining high population immunity with 2 doses of MCV, improving sensitive case-based surveillance, identifying and vaccinating high-risk subpopulation groups, and appropriately responding to outbreaks are key steps needed to achieve the goal.
The Journal of Infectious Diseases 07/2011; 204 Suppl 1:S289-98. · 6.41 Impact Factor
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ABSTRACT: Measles was a leading cause of infant and child morbidity and mortality in Bahrain before the introduction of measles vaccine in 1974. With the establishment of the Expanded Program on Immunization (EPI) in 1981 and the introduction of a second dose of measles vaccine in 1985, coverage for first and second doses of measles vaccine increased to 94% by 1997 and has been sustained >97% since 2001. Measles, mumps, and rubella (MMR) immunization campaigns targeting 12-year-old students were conducted annually during 1998-2006 and achieved coverage of >95%. As a result, the incidence of measles in Bahrain has declined markedly over the past 4 decades, to 2.7 cases per million persons in 2009. Recent confirmed measles cases have occurred sporadically, in undervaccinated children or in infants too young or adults too old to receive measles vaccine. Bahrain has made significant progress toward measles elimination by sustaining high immunization coverage and strengthening case-based measles surveillance activities. Further success will depend on improved identification and immunization of undervaccinated expatriate workers and their families.
The Journal of Infectious Diseases 07/2011; 204 Suppl 1:S299-304. · 6.41 Impact Factor
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ABSTRACT: Measles is still one of the most common infectious killers of children in the world, especially in developing countries. In Iran, during the prevaccine era, 150,000-500,000 cases of measles were reported annually, with a death rate of 10%-15%. After the establishment of Expanded Program on Immunization program in 1984, vaccination rates for the first and second doses of measles vaccine increased to >90% by the mid-1990s, and the number of measles cases decreased to 2652 in 1996. In response to increased numbers of cases in older age groups during 1996-2002, a nationwide measles-rubella vaccination campaign was conducted in 2003, and 33,100,000 persons (99%) aged 5-25 years were vaccinated. During 2004-2009, 221 laboratory-confirmed measles cases (<1 case per million population) were detected, primarily in rural areas and among migrant groups who traveled to or came from high-incidence countries. High routine immunization coverage, low disease incidence, and surveillance system data suggest that interruption of endemic virus transmission might have already been achieved in Iran, but challenges remain and continued efforts are needed to sustain this accomplishment.
The Journal of Infectious Diseases 07/2011; 204 Suppl 1:S305-11. · 6.41 Impact Factor
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ABSTRACT: In 2006, the largest mumps outbreak in the United States in 20 years occurred. To understand prior mumps seroprevalence and factors associated with the presence of antibody to mumps virus, data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) were analyzed.
A mumps virus-specific enzyme immunoassay was used to measure the seroprevalence of serum immunoglobulin G (IgG) antibody among NHANES participants aged 6-49 years. Participants were grouped on the basis of 10-year birth cohorts, 95% confidence intervals (CIs) were calculated using SUDAAN software, and logistic regression was used to identify independent predictors.
The overall age-adjusted seroprevalence of IgG antibody to mumps virus during 1999-2004 was 90.0% (95% CI, 88.8%-91.1%). Seroprevalence was higher among US-born non-Hispanic blacks (96.4% [95% CI, 95.5%-97.2%]) and non-US-born Mexican Americans (93.7% [95% CI, 92.0%-95.2%]). Seroprevalence was significantly lower in the 1967-1976 birth cohort (85.7% [95% CI, 83.5%-87.8%]). The variables sex, education, and race/ethnicity/birthplace were independent predictors in at least 1 of the birth cohorts.
The overall estimate of 90.0% is at the lower end of the estimated population immunity (90%-92%) needed to achieve herd immunity. Lower seroprevalence among groups suggest that they represent populations at an increased risk. For mumps control, high vaccine coverage and high population immunity must be achieved and maintained.
The Journal of Infectious Diseases 09/2010; 202(5):667-74. · 6.41 Impact Factor
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ABSTRACT: Eradication of a disease promises significant health and financial benefits. Preserving those benefits, hopefully in perpetuity, requires preparing for the possibility that the causal agent could re-emerge (unintentionally or intentionally). In the case of a vaccine-preventable disease, creation and planning for the use of a vaccine stockpile becomes a primary concern. Doing so requires consideration of the dynamics at different levels, including the stockpile supply chain and transmission of the causal agent. This paper develops a mathematical framework for determining the optimal management of a vaccine stockpile over time. We apply the framework to the polio vaccine stockpile for the post-eradication era and present examples of solutions to one possible framing of the optimization problem. We use the framework to discuss issues relevant to the development and use of the polio vaccine stockpile, including capacity constraints, production and filling delays, risks associated with the stockpile, dynamics and uncertainty of vaccine needs, issues of funding, location, and serotype dependent behavior, and the implications of likely changes over time that might occur. This framework serves as a helpful context for discussions and analyses related to the process of designing and maintaining a stockpile for an eradicated disease.
Vaccine 06/2010; 28(26):4312-27. · 3.77 Impact Factor
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James P Alexander,
Kristen Ehresmann,
Jane Seward,
Gary Wax,
Kathleen Harriman,
Susan Fuller,
Elizabeth A Cebelinski,
Qi Chen,
Jaume Jorba,
Olen M Kew,
Mark A Pallansch,
M Steven Oberste,
Mark Schleiss,
Jeffrey P Davis,
Bryna Warshawsky,
Susan Squires,
Harry F Hull
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ABSTRACT: Oral poliovirus vaccine (OPV) has not been used in the United States since 2000. Type 1 vaccine-derived poliovirus (VDPV) was identified in September 2005, from an unvaccinated Amish infant hospitalized in Minnesota with severe combined immunodeficiency. An investigation was conducted to determine the source of the virus and its means of transmission.
The infant was tested serially for poliovirus excretion. Investigations were conducted to detect poliovirus infections or paralytic poliomyelitis in Amish communities in Minnesota, neighboring states, and Ontario, Canada. Genomic sequences of poliovirus isolates were determined for phylogenetic analysis.
No source for the VDPV could be identified. In the index community, 8 (35%) of 23 children tested, including the infant, had evidence of type 1 poliovirus or VDPV infection. Phylogenetic analysis suggested that the VDPV circulated in the community for approximately 2 months before the infant's infection was detected and that the initiating OPV dose had been given before her birth. No paralytic disease was found in the community, and no poliovirus infections were found in other Amish communities investigated.
This is the first demonstrated transmission of VDPV in an undervaccinated community in a developed country. Continued vigilance is needed in all countries to identify poliovirus infections in communities at high risk of poliovirus transmission.
The Journal of Infectious Diseases 01/2009; 199(3):391-7. · 6.41 Impact Factor
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Allison Kempe,
Matthew F Daley,
Umesh D Parashar,
Lori A Crane,
Brenda L Beaty,
Shannon Stokley,
Jennifer Barrow,
Christine Babbel,
L Miriam Dickinson,
Marc-Alain Widdowson, James P Alexander,
Stephen Berman
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ABSTRACT: Our objective was to determine the following among US pediatricians: (1) perceptions regarding burden of rotavirus disease and need for a vaccine; (2) intentions for recommending a newly licensed rotavirus vaccine; (3) perceived barriers to implementation; and (4) factors associated with plans for vaccine adoption.
A network of 431 pediatricians was recruited from a random sample of American Academy of Pediatrics' members. The network was designed to be representative of the American Academy of Pediatrics with respect to region of the country, practice type, and practice setting. During January and February 2006, physicians were surveyed by Internet or mail. The survey contained a paragraph summarizing results of the new rotavirus vaccine trial. Respondents were asked about intentions to use the vaccine and anticipated barriers.
The survey response rate was 71%. Of the respondents, 52% strongly agreed and 37% somewhat agreed with the need for a rotavirus vaccine. If recommended for routine use, 50% would strongly recommend and 34% would recommend but not strongly; 52% would begin to use within 6 months and 27% from 6 months to 1 year. The top 3 "definite" barriers to implementation included concerns about uniform coverage of vaccine by insurers, lack of adequate reimbursement, and parental reluctance because of withdrawal of previous rotavirus vaccine. In multivariate analysis, factors associated with very likely adoption of the vaccine included perception of a high burden of rotavirus disease and a high level of confidence in prelicensure studies of vaccine safety. The presence of physician concerns about safety of the new vaccine and the perception of parental concerns about vaccine safety in general were negatively associated with adoption.
The majority of pediatricians reported willingness to implement the new rotavirus vaccine, most within 6 months. Major barriers to optimal implementation included provider concerns about reimbursement issues and parental acceptance of the vaccine.
PEDIATRICS 02/2007; 119(1):1-10. · 4.47 Impact Factor
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Kimberly M Thompson,
Radboud J Duintjer Tebbens,
Mark A Pallansch,
Olen M Kew,
Roland W Sutter,
R Bruce Aylward,
Margaret Watkins,
Howard Gary, James P Alexander,
Linda Venczel,
Denise Johnson,
Victor M Cáceres,
Nalinee Sangrujee,
Hamid Jafari,
Stephen L Cochi
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ABSTRACT: The success of the Global Polio Eradication Initiative promises to bring large benefits, including sustained improvements in quality of life (i.e., cases of paralytic disease and deaths avoided) and costs saved from cessation of vaccination. Obtaining and maintaining these benefits requires that policymakers manage the transition from the current massive use of oral poliovirus vaccine (OPV) to a world without OPV and free of the risks of potential future reintroductions of live polioviruses. This article describes the analytical journey that began in 2001 with a retrospective case study on polio risk management and led to development of dynamic integrated risk, economic, and decision analysis tools to inform global policies for managing the risks of polio. This analytical journey has provided several key insights and lessons learned that will be useful to future analysts involved in similar complex decision-making processes.
Risk Analysis 01/2007; 26(6):1571-80. · 2.37 Impact Factor
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ABSTRACT: In February 2006, a live, oral, human-bovine reassortant rotavirus vaccine (RotaTeq) was licensed for use among U.S. infants. The Advisory Committee on Immunization Practices recommends routine vaccination of U.S. infants with 3 doses of this rotavirus vaccine administered orally at ages 2, 4, and 6 months. The first dose should be administered between ages 6-12 weeks. Subsequent doses should be administered at 4-10 week intervals, and all 3 doses should be administered by age 32 weeks. Rotavirus vaccine can be co-administered with other childhood vaccines. Rotavirus vaccine is contraindicated for infants with a serious allergic reaction to any vaccine component or to a previous dose of vaccine.
MMWR. Recommendations and reports: Morbidity and mortality weekly report. Recommendations and reports / Centers for Disease Control 09/2006; 55(RR-12):1-13.
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Kimberly M Thompson,
Gregory S Wallace,
Radboud J Duintjer Tebbens,
Philip J Smith,
Albert E Barskey,
Mark A Pallansch,
Kathleen M Gallagher, James P Alexander,
Gregory L Armstrong,
Stephen L Cochi,
Steven G F Wassilak
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ABSTRACT: The United States eliminated indigenous wild polioviruses (WPVs) in 1979 and switched to inactivated poliovirus vaccine in 2000, which quickly ended all indigenous live poliovirus transmission. Continued WPV circulation and use of oral poliovirus vaccine globally allow for the possibility of reintroduction of these viruses. We evaluated the risk of a U.S. polio outbreak and explored potential vaccine needs for outbreak response.
We synthesized information available on vaccine coverage, exemptor populations, and population immunity. We used an infection transmission model to explore the potential dynamics of a U.S. polio outbreak and potential vaccine needs for outbreak response, and assessed the impacts of heterogeneity in population immunity for two different subpopulations with potentially low coverage.
Although the risk of poliovirus introduction remains real, widespread transmission of polioviruses appears unlikely in the U.S., given high routine coverage. However, clusters of un- or underimmunized children might create pockets of susceptibility that could potentially lead to one or more paralytic polio cases. We found that the shift toward combination vaccine utilization, with limited age indications for use, and other current trends (e.g., decreasing proportion of the population with immunity induced by live polioviruses and aging of vaccine exemptor populations) might increase the vulnerability to poliovirus reintroduction at the same time that the ability to respond may decrease.
The U.S. poliovirus vaccine stockpile remains an important resource that may potentially be needed in the future to respond to an outbreak if a live poliovirus gets imported into a subpopulation with low vaccination coverage.
Public Health Reports 127(1):23-37. · 1.27 Impact Factor
