Herd immunity after pneumococcal conjugate vaccination

Division of Infectious Diseases, Emory University, Atlanta, Georgia, United States
The Lancet (Impact Factor: 45.22). 08/2007; 370(9583):218-9; author reply 219-20. DOI: 10.1016/S0140-6736(07)61119-2
Source: PubMed
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    ABSTRACT: To summarize recent evidence regarding associations of early life exposure to mercury from maternal fish consumption during pregnancy, thimerosal in vaccines and dental amalgam with child neurodevelopment. Recent publications have built upon previous evidence demonstrating mild detrimental neurocognitive effects from prenatal methylmercury exposure from maternal fish consumption during pregnancy. New studies examining the effects of prenatal fish consumption as well as methylmercury suggest there are benefits from prenatal fish consumption, but also that consumption of fish high in mercury should be avoided. Future studies incorporating information on both the methylmercury and the docosahexaenoic acid contained within fish will help to refine recommendations to optimize outcomes for mothers and children. Additional recent studies have supported the safety of vaccines containing thimerosal and of dental amalgam for repair of dental caries in children. Exposure to mercury may harm child development. Interventions intended to reduce exposure to low levels of mercury in early life must, however, be carefully evaluated in consideration of the potential attendant harm from resultant behavior changes, such as reduced docosahexaenoic acid exposure from lower seafood intake, reduced uptake of childhood vaccinations and suboptimal dental care.
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    ABSTRACT: Conjugate vaccines exist that offer protection against disease caused by Haemophilus influenzae type b (Hib), and selected serogroups/serotypes of Neisseria meningitidis and Streptococcus pneumoniae. These vaccines are not only able to prevent serious disease, but they also provide protection against asymptomatic carriage. The resulting herd immunity effects have been striking, and have played an important role in the public health success of conjugate vaccination programmes. The aim of this paper is to review the state of the current evidence on conjugate vaccines and to identify important areas for further study, in order to inform the debate regarding the best use of these vaccines.
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