Vaccine
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We have just witnessed the largest and most devastating outbreak of Ebola virus disease, which highlighted the urgent need for development of an efficacious vaccine that could be used to curtail future outbreaks. Prior to 2014, there had been limited impetus worldwide to develop a vaccine since the virus was first discovered in 1976. Though too many lives were lost during this outbreak, it resulted in the significantly accelerated clinical development of a number of candidate vaccines through an extraordinary collaborative global effort coordinated by the World Health Organisation (WHO) and involving a number of companies, trial centres, funders, global stakeholders and agencies. ⋯ Though the Public Health Emergency of International Concern (PHEIC) declared by the WHO has now been lifted, the global scientific community faces numerous challenges ahead to ensure that there is a licensed, deployable vaccine available for use in future outbreaks for at least the Zaire and Sudan strains of Ebola virus. There remain several unanswered questions on the durability of protection, mechanistic immunological correlates and preferred deployment strategies. This review outlines a brief history of the development of Ebola vaccines, the significant progress made since the scale of the outbreak became apparent, some lessons learnt and how they could shape future development of vaccines and the management of similar outbreaks.
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Widespread introduction of pneumococcal conjugated vaccines (PCVs) impacted on invasive pneumococcal disease (IPD). However, IPD reduction may not be similar in all outcomes within IPD. We assessed PCV7/PCV13 impact on pneumococcal meningitis, bacteremic pneumonia (BP) and other (non-meningitis, non-pneumonia) IPD episodes in children <5years in Israel. ⋯ Following PCV7/PCV13 introduction, rates of episodes caused by VT13 were substantially reduced in all 3 groups. However, differences in age distribution, serotype replacement and specific serotype decrease suggest different pathogenesis and host susceptibility between the 3 entities.
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Inequalities in measles immunization coverage facilitate the onset of outbreaks. This study aimed to quantify socioeconomic inequalities associated with measles immunization coverage at the population level. ⋯ The spatial dependence between measles vaccination coverage and socioeconomic disparities suggests clusters of vulnerable populations for outbreaks. Health and social inequalities must be considered to achieve and maintain measles elimination.
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Childhood mortality in Afghanistan fell by half between 1990 and 2015, due in part to the government's commitment to improving pediatric immunization services. Although progress has been made, immunization coverage has nonetheless remained low with only 65% of children receiving the third dose of Diphtheria-Pertussis-Tetanus (DPT3) based on WHO estimates. This study aims to calculate the proportion of Afghan children aged 1-4 years who were fully vaccinated, under-vaccinated, or non-vaccinated with government-recommended Expanded Program on Immunization vaccines and identify predictors related to the family's sociodemographic status and maternal autonomy. ⋯ Approximately 60% of children in Afghanistan are under-vaccinated or non-vaccinated, leaving millions of children unnecessarily at risk for vaccine-preventable diseases. Engagement with community and religious leaders to create programs that increase women's autonomy and expand access to institutional delivery could lead to downstream increases in childhood vaccination coverage.
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Current influenza vaccines do not provide effective protection against heterologous influenza viruses. The ability of the novel M2SR influenza vaccine to protect against drifted influenza viruses was evaluated in naïve ferrets and in ferrets with pre-existing immunity to influenza. In naïve ferrets, M2SR provided similar protection against drifted challenge viruses as the comparator vaccine, FluMist®. ⋯ While cross-reactive serum IgG antibodies against the Bris59 HA were detected after vaccination, anti-Bris59 hemagglutination inhibition antibodies were only detected post-challenge. M2SR provided better protection against Bris59 challenge than FluMist suggesting that homologous pre-existing immunity affected FluMist virus to a greater degree than M2SR. These results suggest that the single replication intranasal M2SR vaccine provides effective protection against drifted influenza A viruses not only in naïve ferrets but also in those with pre-existing immunity in contrast to FluMist viruses.