Impact of Pneumococcal Conjugate Vaccines on Pneumonia Hospitalizations in High- and Low-Income Subpopulations in Brazil.

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) are being used worldwide. A key question is whether the impact of PCVs on pneumonia is similar in low- and high-income populations. However, most low-income countries, where the burden of disease is greatest, lack reliable data that can be used to evaluate the impact. Data from middle-income countries that have both low- and high-income subpopulations can provide a proxy measure for the impact of the vaccine in low-income countries. METHODS: We evaluated the impact of PCV10 on hospitalizations for all-cause pneumonia in Brazil, a middle-income country with localities that span a broad range of human development index (HDI) levels. We used complementary time series and spatiotemporal methods (synthetic controls and hierarchical Bayesian spatial regression) to test whether the decline in pneumonia hospitalizations associated with vaccine introduction varied across the socioeconomic spectrum. RESULTS: We found that the declines in all-cause pneumonia hospitalizations in children and young and middle-aged adults did not vary substantially across low and high HDI subpopulations. Moreover, the estimated declines seen in infants and young adults were associated with higher levels of uptake of the vaccine at a local level. CONCLUSIONS: These results suggest that PCVs have an important impact on hospitalizations for all-cause pneumonia in both low- and high-income populations.

Modelling estimates of the burden of respiratory syncytial virus infection in children in the UK.

OBJECTIVE: The burden of respiratory syncytial virus (RSV) illness is not well characterised in primary care. We estimated the burden of disease attributable to RSV in children in the UK between 1995 and 2009. DESIGN: Time-series regression modelling. SETTING: A multiple linear regression model based on weekly viral surveillance (RSV and influenza, Public Health England), and controlled for non-specific seasonal drivers of disease, estimated the proportion of general practitioner (GP) episodes of care (counted as first visit in a series within 28 days; Clinical Practice Research Datalink, CPRD), hospitalisations (Hospital Episode Statistics, HES) and deaths (Office of National Statistics, ONS) attributable to RSV each season. PARTICIPANTS: Children 0-17 years registered with a GP in CPRD, or with a respiratory disease outcome in the HES or ONS databases. PRIMARY OUTCOME MEASURES: RSV-attributable burden of GP episodes, hospitalisations and deaths due to respiratory disease by age. RSV-attributable burden associated with selected antibiotic prescriptions. RESULTS: RSV-attributable respiratory disease in the UK resulted in an estimated 450 158 GP episodes, 29 160 hospitalisations and 83 deaths per average season in children and adolescents, with the highest proportions in children <6 months of age (14 441/100 000 population, 4184/100 000 and 6/100 000, respectively). In an average season, there were an estimated 125 478 GP episodes for otitis media and 416 133 prescriptions for antibiotics attributable to RSV. More GP episodes, hospitalisations and deaths from respiratory disease were attributable to RSV than to influenza in children under 5 years. CONCLUSIONS: The burden of RSV in children in the UK exceeds that of influenza. RSV in children and adolescents contributes substantially to GP office visits for a diverse range of illnesses, and was associated with an average 416 133 prescribed antibiotic courses per season. Effective antiviral treatments and preventive vaccines are urgently needed for the management of RSV infection in children. TRIAL REGISTRATION NUMBER: NCT01706302.

Use of near-real-time medical claims data to generate timely vaccine coverage estimates in the US: the dynamics of PCV13 vaccine uptake.

BACKGROUND: Vaccine coverage estimates lag by years in the US. Commercially available medical claims databases contain timely records of childhood vaccinations given in physician offices. We used such data to track the replacement of the 7-valent pneumococcal conjugate vaccine (PCV7) by PCV13, a new vaccine active against 6 additional serotypes, starting in March 2010. METHODS: We developed an age cohort model to compute vaccination coverage over time. We used age-stratified, national projections of monthly PCV7 and PCV13 doses administered to children <5 years based on physicians' office claims, January 2008-May 2012. We assumed doses were given on schedule, and tracked cumulative numbers of doses given to aging monthly cohorts to estimate the percentage of children fully PCV13-immunized. To account for children uninsured or in the Vaccines for Children program, estimates were projected using National Immunization Survey coverage data. RESULTS: PCV7 was phased out by June 2010. By March 2012, 82% of children 6-23 months were fully immunized with PCV13 and 42% of toddlers aged 15-59 months had received a catch-up PCV13 dose. For children aged 6-59 months, protective PCV13 coverage levels reached 33% and 56% by March 2011 and 2012, respectively, and were projected to reach 88% by March 2014. Our estimates for children aged 0-59 and 24-59 months are consistent with CDC's Immunization Information System sentinel sites data for 2011-2012. CONCLUSIONS: By using a simple analytic approach to compute vaccine coverage in aging cohorts from claims data, we show that PCV13 coverage rose rapidly as the PCV7 program was replaced. These estimates, validated against a CDC sentinel surveillance system in 8 states, should enable early documentation of the PCV13 impact on pneumococcal disease in the US. Moreover, they demonstrate the feasibility of tracking uptake patterns in near real-time even with simple summary counts of medical claims data.

Public preparedness guidance for a severe influenza pandemic in different countries: a qualitative assessment and critical overview.

During a severe influenza pandemic individuals and families can, by following well-directed and scientifically-based measures, not only benefit themselves but also play an effective role in reducing transmission rates and the burden on public services. Such guidelines should be provided as clearly and comprehensively as possible by official sources. Here we examine the official recommendations issued by 10 countries to prepare their citizens for a severe pandemic. We have found the presence of hazardous guidelines - as the advice to personally visit a health center at the earliest symptoms - and shortage of practical advices for home isolation, business preparation and treatment to be widespread. Our review shows that, while many positive recommendations were provided, the set of recommendations issued by most countries was not comprehensive enough for severe influenza scenarios. This is a situation that needs revision.

Sex-ratio conflicts, kin selection, and the evolution of altruism.

Kin-selection theory has thrived in the explanation of a wide variety of biological phenomena, chiefly the evolution of biological altruism as that found in sterile castes of eusocial insects. Much of the way in which it has been tested is based on the existence of conflicts over sex-ratio production within eusocial colonies. However, despite neatly showing eusocial colonies as arenas where selection at the gene level triggers the appearance of sophisticated disputes, these studies have only demonstrated the existence of genes that act by biasing sex ratios to promote their own spread. Here we argue that such genes depend on the social organization of the colonies where they are expressed, but that they are not, in any way, the precursors of these societies-the major implication being that unequivocal evidence that eusociality evolved through the action of kin-selected altruistic genes is still lacking. Additionally, we highlight the neglect of alternative theories on the explanation of both biological altruism and sex-ratio conflicts, and defend that the enthusiasm with the latter has, in some cases, led to its inappropriate use as a basis for the explanation of other biological characteristics of eusocial organisms, when accounts based on phylogenetic or physiological constraints are also available.