Streptococcus pneumoniae causes mucosal and invasive diseases with high morbidity and mortality. Introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) into routine infant immunization programs worldwide resulted in serotype 19A becoming a leading cause of the remaining pneumococcal disease burden in vaccinated and nonvaccinated individuals. This article reviews the impact of the latest generation PCVs (10-valent PCV, PCV10, and 13-valent PCV, PCV13) on serotype 19A. Areas covered: This article covers immune responses elicited by PCV7, PCV10 and PCV13 against serotype 19A and their impact on nasopharyngeal (NP) carriage and disease in vaccinated and unvaccinated populations using data from surveillance systems, randomized controlled trials, and observational studies. Expert commentary: As expected from a PCV containing serotype 19A, PCV13 elicits significantly higher functional immune responses against serotype 19A than PCV7 and PCV10. Higher responses are likely to be linked to both direct impact in vaccinated populations and reductions in 19A NP carriage in children, thus inducing herd protection and reducing 19A invasive pneumococcal disease (IPD) in nonvaccinated children and adults. In contrast, PCV7 and PCV10 have shown mixed evidence of direct short-lived cross-protection and little to no impact on 19A carriage, resulting in continued transmission and disease.
BackgroundThe burden of pneumococcal disease in China is high, and a 13-valent pneumococcal conjugate vaccine (PCV13) recently received regulatory approval and is available to Chinese infants. PCV13 protects against the most prevalent serotypes causing invasive pneumococcal disease (IPD) in China, but will not provide full societal benefits until made broadly available through a national immunization program (NIP).ObjectiveTo estimate clinical and economic benefits of introducing PCV13 into a NIP in China using local cost estimates and accounting for variability in vaccine uptake and indirect (herd protection) effects.MethodsWe developed a population model to estimate the effect of PCV13 introduction in China. Modeled health states included meningitis, bacteremia, pneumonia (PNE), acute otitis media, death and sequelae, and no disease. Direct healthcare costs and disease incidence data for IPD and PNE were derived from the China Health Insurance and Research Association database; all other parameters were derived from published literature. We estimated total disease cases and associated costs, quality-adjusted life years (QALYs), and deaths for three scenarios from a Chinese Payer Perspective: (1) direct effects only, (2) direct+indirect effects for IPD only, and (3) direct+indirect effects for IPD and inpatient PNE.ResultsScenario (1) resulted in 370.3 thousand QALYs gained and 12.8 thousand deaths avoided versus no vaccination. In scenarios (2) and (3), the PCV13 NIP gained 383.2 thousand and 3,580 thousand QALYs, and avoided 13.1 thousand and 147.5 thousand deaths versus no vaccination, respectively. In all three scenarios, the vaccination cost was offset by cost reductions from prevented disease yielding net costs of ¥29,362.32 million, ¥29,334.29 million, and ¥13,524.72 million, respectively. All resulting incremental cost-effectiveness ratios fell below a 2x China GDP cost-effectiveness threshold across a range of potential vaccine prices.DiscussionInitiation of a PCV13 NIP in China incurs large upfront costs but is good value for money, and is likely to prevent substantial cases of disease among children and non-vaccinated individuals.
The 13-valent pneumococcal conjugate vaccine (PCV) has been part of routine immunisation in a 2 + 1 schedule (two primary infant doses and one booster during the second year of life) in the UK since 2010. Recently, the UK's Joint Committee on Vaccination and Immunisation recommended changing to a 1 + 1 schedule while conceding that this will increase disease burden; however, uncertainty remains on how much pneumococcal burden - including invasive pneumococcal disease (IPD) and non-invasive disease - will increase. We built a dynamic transmission model to investigate this question. The model predicted that a 1 + 1 schedule would incur 8777-27 807 additional cases of disease and 241-743 more deaths over 5 years. Serotype 19A caused 55-71% of incremental IPD cases. Scenario analyses showed that booster dose adherence, effectiveness against carriage and waning in a 1 + 1 schedule had the most influence on resurgence of disease. Based on the model assumptions, switching to a 1 + 1 schedule will substantially increase disease burden. The results likely are conservative since they are based on relatively low vaccine-type pneumococcal transmission, a paradigm that has been called into question by data demonstrating an increase of IPD due to several vaccine serotypes during the last surveillance year available.
A large-scale, postmarketing observational database safety study was conducted following 7-valent pneumococcal conjugate vaccine (PCV7) licensure. A secondary outcome was the occurrence of predefined diagnoses among PCV7 vaccinees versus historic controls. Forty-two PCV7 recipients and 17 controls were hospitalized for Kawasaki disease (P = 0.012). After adjusting for potential confounding variables, this difference was not significant (P = 0.083). No association between Kawasaki disease and PCV7 was found.
makes a proportion of patients to be at serious risk of severe disease with complications and possible fatal outcome.
Conclusion:A quarter century of its re-emergence in Bulgaria MSF is still potentially active despite the decreasing incidence and mortality rate.
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