The estimated mortality impact of vaccinations forecast to be administered during 2011–2020 in 73 countries supported by the GAVI Alliance

Vaccine (Impact Factor: 3.62). 04/2013; 31(Suppl. 2):B61–B72. DOI: 10.1016/j.vaccine.2012.11.035


IntroductionFrom August to December 2011, a multidisciplinary group with expertise in mathematical modeling was constituted by the GAVI Alliance and the Bill & Melinda Gates Foundation to estimate the impact of vaccination in 73 countries supported by the GAVI Alliance.Methods
The number of deaths averted in persons projected to be vaccinated during 2011–2020 was estimated for ten antigens: hepatitis B, yellow fever, Haemophilus influenzae type B (Hib), Streptococcus pneumoniae, rotavirus, Neisseria meningitidis serogroup A, Japanese encephalitis, human papillomavirus, measles, and rubella. Impact was calculated as the difference in the number of deaths expected over the lifetime of vaccinated cohorts compared to the number of deaths expected in those cohorts with no vaccination. Numbers of persons vaccinated were based on 2011 GAVI Strategic Demand Forecasts with projected dates of vaccine introductions, vaccination coverage, and target population size in each country.ResultsBy 2020, nearly all GAVI-supported countries with endemic disease are projected to have introduced hepatitis B, Hib, pneumococcal, rotavirus, rubella, yellow fever, N. meningitidis serogroup A, and Japanese encephalitis-containing vaccines; 55 (75 percent) countries are projected to have introduced human papillomavirus vaccine. Projected use of these vaccines during 2011–2020 is expected to avert an estimated 9.9 million deaths. Routine and supplementary immunization activities with measles vaccine are expected to avert an additional 13.4 million deaths. Estimated numbers of deaths averted per 1000 persons vaccinated were highest for first-dose measles (16.5), human papillomavirus (15.1), and hepatitis B (8.3) vaccination. Approximately 52 percent of the expected deaths averted will be in Africa, 27 percent in Southeast Asia, and 13 percent in the Eastern Mediterranean.Conclusion
Vaccination of persons during 2011–2020 in 73 GAVI-eligible countries is expected to have substantial public health impact, particularly in Africa and Southeast Asia, two regions with high mortality. The actual impact of vaccination in these countries may be higher than our estimates because several widely used antigens were not included in the analysis. The quality of our estimates is limited by lack of data on underlying disease burden and vaccine effectiveness against fatal disease outcomes in developing countries. We plan to update the estimates annually to reflect updated demand forecasts, to refine model assumptions based on results of new information, and to extend the analysis to include morbidity and economic benefits.

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Available from: Yvonne Tam, Mar 11, 2015
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    • "The " Reaching Every District " (RED) WHO approach, implemented in Africa since 2002, has also contributed to improve childhood immunization services increasing coverage rates from 73% to 94% for different antigens in 2009 worldwide (Tao et al., 2013). The continuous uptake of vaccination will avert over 20 million deaths during the 2011–2020 period worldwide, 52% of which will be in African countries (Lee et al., 2013). Despite the encouraging figures, two main concerns have arisen. "
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    ABSTRACT: Vaccines are an effective public health measure. Vaccination coverage has improved in Africa in the last decades but has still not reached WHO/UNICEF target of at least 90% first-dose coverage for vaccines in the Expanded Programme on Immunization (EPI) implemented in Mozambique in 1979. There are concerns about reliability of vaccination coverage official data from low-income countries, and inequities in vaccine administration. We randomly sampled 266 under-five years children from Taninga, a poor rural area in Southern Mozambique under a Demographic Surveillance System and collected data directly from the individual national health cards when available (BCG, DTP/HepB/Hib, Polio, Measles). We also collected data on socio-economic variables through an interview. Overall, only 5% of the participants did not receive all the doses of the vaccines included in the EPI in a timely manner (overall vaccination coverage 95%, 95%CI: 93.5%-95.5%). The socio-economic status was homogenously low and no differences were found between vaccinated and unvaccinated children. Vaccination coverage in Taninga was very high, despite the low socio-economic status of the population. The high performance of the EPI in Taninga is an encouraging experience for achieving high vaccination coverage in low-income rural settings. Copyright © 2015. Published by Elsevier B.V.
    Acta tropica 06/2015; 149. DOI:10.1016/j.actatropica.2015.06.007 · 2.27 Impact Factor
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    • "Between countries, there are higher rates of cervical cancer in low income countries. Projected increased HPV vaccination globally from 2011 to 2020 has been estimated to be capable of averting half a million future deaths, or 15.1 deaths per 1000 girls vaccinated [8], which will inevitably contribute to reducing between country cervical cancer inequalities. Within countries, cervical cancer rates [9–12] and other HPV-associated cancer rates are higher among lower socioeconomic, and minority and indigenous populations [13,14]. "
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    ABSTRACT: Background: As with many high-income countries, vaccination coverage against human papilloma virus (HPV) infection is not high in New Zealand (NZ) at 47% in school-aged girls for three doses. We estimate the health gains, net-cost and cost-effectiveness of the currently implemented HPV national vaccination programme of vaccination dispersed across schools and primary care, and two alternatives: school-based only (assumed coverage as per Australia: 73%), and mandatory school-based vaccination but with opt-out permitted (coverage 93%). We also generate estimates by social group (sex, ethnic and deprivation group). Methods: A Markov macro-simulation model was developed for 12-year-old girls and boys in 2011, with future health states of: cervical cancer, pre-cancer (CIN I-III), genital warts, and three other HPV-related cancers (oropharyngeal, anal, vulvar cancer). In each state health sector costs, including additional health sector costs from extra life, and quality-adjusted life years (QALYs) were accumulated. Results: The current HPV vaccination programme has an estimated cost-effectiveness of NZ$18,800/QALY gained (about US$9700/QALY gained using the OECD's purchasing power parities; 95% UI: US$6900 to $33,700) compared to the status quo in NZ prior to 2008 (no vaccination, screening alone). The incremental cost-effectiveness ratio (ICER) of an intensive school-based only programme of girls, compared to the current situation, was US$33,000/QALY gained. Mandatory vaccination appeared least cost-effective (ICER compared to school-based of US$117,000/QALY gained, but with wide 95% uncertainty limits from $56,000 to $220,000). All interventions generated more QALYs per 12-year-old for Māori (indigenous population) and people living in deprived areas (range 5-25% greater QALYs gained). Interpretation: A more intensive school-only vaccination programme seems warranted. Reductions in vaccine price will greatly improve cost-effectiveness of all options, possibly making a law for mandatory vaccination optimal from a health sector perspective. All interventions could reduce ethnic and socioeconomic disparities in HPV-related disease.
    Vaccine 03/2014; DOI:10.1016/j.vaccine.2014.02.071 · 3.62 Impact Factor
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    • "Rotaviruses (RVs) are a major cause of acute gastroenteritis in infants and young children and impose a heavy disease burden worldwide resulting in substantial mortality (450,000–500,000 children of <5-year-old/annum), mainly in developing countries in sub-Saharan Africa, Asia and S America (Parashar et al., 2003, 2009; Tate et al., 2012). Two live, attenuated RV vaccines have been licensed in over 100 countries since 2006 and are in wide use (Desselberger et al., 2009; Yen et al., 2011) with so far very encouraging outcomes in relation to the reduction of hospitalisation for RV-associated acute gastroenteritis (AGE) and also of mortality (Yen et al., 2011; Patel et al., 2012; Soares-Weiser et al., 2012; Gastã naduy et al., 2013; Lee et al., 2013). "
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    ABSTRACT: Rotavirus (RV) cores were released from double-layered particles (DLPs) by high concentrations of CaCl2, purified and 'opened' by treatment with EDTA or EGTA. Under appropriate in vitro conditions DLPs have been shown to have transcriptase and 'open cores' replicase activity. Furthermore, it has been demonstrated that transcriptase activity and infectivity of native cores can be restored by transcapsidation with VP6, VP7 and VP4. The missing link for particle reconstitution in vitro has been the manipulation of 'open cores' to become functionally active cores again. The experiments described here were undertaken with the aim of exploring packaging of RV RNAs into opened cores in vitro. Rotavirus cores were opened by approx. 200 uM EGTA, leading to the release of genomic dsRNA. Conversely, RV cores were found to be stable in the presence of minimum concentrations of Ca(2+), Mg(2+), spermidine(3+) and cobalthexamine(3+) of between 40 and 300 uM. Aggregates of purified cores were resolved in the presence of 0.3mM deoxycholate (minimum concentration). Core shells opened with EGTA were reconstituted by the addition of di- or trivalent cations within 2min of the opening procedure. Addition of purified, baculovirus recombinant-expressed VP6 to native and reconstituted cores led to the formation of DLPs or DLP-like particles, which upon transfection into MA104 cells were infectious. The rescued infectivity likely originated in part from unopened and in part from reconstituted cores. Radiolabelled RV (+) ssRNAs could be packaged into reconstituted cores and DLPs, as indicated by resistance to RNase I digestion. The packaging reaction was, however, not RV RNA sequence-specific, since unrelated ssRNAs, such as those transcribed from HIV-2 cDNAs, were also packaged. The kinetics of packaging of homologous and heterologous RNAs were similar, as evidenced by competitive packaging assays. None of the packaged in vitro engineered RNA segments has so far been rescued into infectious virus.
    Virus Research 09/2013; 178(2). DOI:10.1016/j.virusres.2013.09.034 · 2.32 Impact Factor
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