Impact of 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) on childhood pneumonia hospitalizations in Brazil two years after introduction

Nasopharyngeal carriage of Streptococcus pneumoniae among Brazilian children: Interplay with viral co-infection

Nasopharyngeal transmission of Streptococcus pneumoniae is a prerequisite for the development of pneumococcal diseases. Previous studies have reported a relationship between respiratory viruses and S. pneumoniae infections. However, there are few studies on this issue among healthy children. This study aimed to examine the relationships between these agents in healthy children from Southern Brazil. This cohort study included 229 nasopharyngeal samples collected from children aged 18-59 months at baseline. S. pneumoniae was detected using bacterial culture, whereas respiratory viruses were identified using quantitative polymerase chain reaction. A questionnaire was used at the time of sample collection and medical records were reviewed 14 days after participant inclusion. The prevalence of pneumococcal carriage was 63.7% (146/229), while respiratory viruses were detected in 49.3% (113/229) of the children. Respiratory viruses were more frequently found among pneumococcal carriers than among non-carriers (54.4% vs. 39.7%, p = 0.033). Additionally, rhinovirus (hRV) was more frequent among the pneumococcal carriers (39% vs. 21.7%, p = 0.012), and the presence of human bocavirus (hBOV) alone was associated with the absence of pneumococcal carriage (2.7% vs. 10.8%, p = 0.016). No differences were found in the frequency of pneumococcal carriage, respiratory virus detection, or the co-occurrence of clinical symptoms and diagnosis in the participants 14 days after specimen collection. Our findings revealed a positive relationship between pneumococcal carriage and respiratory virus detection, particularly for hRV. However, we did not observe a relationship between nasopharyngeal respiratory viruses and pneumococci detection during medical appointments, respiratory symptoms, or diseases. This study was one of the first investigations in Latin America to explore the relationship between respiratory viruses and pneumococcal carriage in a healthy children.

Impact of PCV10 on pediatric pneumococcal disease burden in Brazil: time for new recommendations?

OBJECTIVE

To describe the impact of the 10-valent pneumococcal conjugate vaccine on the pediatric burden of pneumococcal infections, carriage, serotype replacement, and antimicrobial resistance in Brazil since its introduction in 2010.

DATA SOURCE

A narrative review of English, Spanish, and Portuguese articles published in online databases and in Brazilian epidemiological surveillance databases was performed. The following keywords were used: Streptococcus pneumoniae, pneumococcal disease, conjugate vaccine, PCV10, antimicrobial resistance, and meningitis.

SUMMARY OF THE FINDINGS

Declines in hospitalization rates of all-cause pneumonia occurred in the target age groups and some age groups not targeted by vaccination early after the use of PCV10. Large descriptive studies of laboratory-confirmed pneumococcal meningitis and hospital-based historical series of hospitalized children with IPD have evidenced a significant impact on disease burden, in-hospital fatality rates, and admission to the intensive care unit before and after the inclusion of the vaccine. Impact data on otitis media is limited and inconsistent; the main benefit remains the prevention of complicated diseases. During the late post-vaccine years, a significant and progressive increase in high-level penicillin non-susceptibility pneumococci has been described. Since 2014 serotype 19A has been the leading serotype in all ages and was responsible for 28.2%-44.6% of all IPD in children under 5 yrs.

CONCLUSIONS

PCV10 has performed a significant impact on IPD in Brazil since 2010, however, progress has been continuously hampered by replacement. Broader spectrum PCVs could provide expanded direct and indirect protection against ST19A and other additional serotypes of increasing importance if administered to children in the Brazilian National Immunization Program.

Etiology and the challenge of diagnostic testing of community-acquired pneumonia in children and adolescents

Background

Pneumonia is the leading cause of mortality in pediatric population. The etiology of pneumonia in this population is variable and changes according to age and disease severity and where the study is conducted. Our aim was to determine the etiology of community-acquired pneumonia (CAP) in children aged 1 month to 17 years admitted to 13 Colombian hospitals.

Methods

Prospective cohort study. Hospitalized children with radiologically confirmed CAP and ≤ 15 days of symptoms were included and followed together with a control group. Induced sputum (IS) was submitted for stains and cultures for pyogenic bacteria and Mycobacterium tuberculosis, and multiplex PCR (mPCR) for bacteria and viruses; urinary antigens for pneumococcus and Legionella pneumophila; nasopharyngeal swabs for viruses, and paired serology for atypical bacteria and viruses. Additional cultures were taken at the discretion of primary care pediatricians.

Results

Among 525 children with CAP, 71.6% had non-severe pneumonia; 24.8% severe and 3.6% very severe pneumonia, and no fatal cases. At least one microorganism was identified in 84% of children and 61% were of mixed etiology; 72% had at least one respiratory virus, 28% pyogenic bacteria and 21% atypical bacteria. Respiratory syncytial virus, Parainfluenza, Rhinovirus, Influenza, Mycoplasma pneumoniae, Adenovirus and Streptococcus pneumoniae were the most common etiologies of CAP. Respiratory syncytial virus was more frequent in children under 2 years and in severe pneumonia. Tuberculosis was diagnosed in 2.3% of children. IS was the most useful specimen to identify the etiology (33.6%), and blood cultures were positive in 3.6%. The concordance between all available diagnostic tests was low. A high percentage of healthy children were colonized by S. pneumoniae and Haemophilus influenzae, or were infected by Parainfluenza, Rhinovirus, Influenza and Adenovirus.

Conclusions

Respiratory viruses are the most frequent etiology of CAP in children and adolescents, in particular in those under 5 years. This study shows the challenges in making an etiologic diagnosis of CAP in pediatric population because of the poor concordance between tests and the high percentage of multiple microorganisms in healthy children. IS is useful for CAP diagnosis in pediatric population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03235-z.

Impact of social distancing in response to COVID-19 on hospitalizations for laryngitis, tracheitis, otitis media, and mastoiditis in children aged 0 to 9 years in Brazil

Objective

The objective of this study is to evaluate the impact of social distancing resulting from COVID-19 in hospitalizations for infections of the upper airways (URTI), such as acute laryngitis, tracheitis, and otitis media in children aged 0 to 9 years in Brazil, considering that they share the same forms of transmission.

Methods

Data on hospitalizations for acute airway changes and their complications in children <9 years old were obtained from the Database of the Brazilian Department of Public Health Informatics for the period 2015 to 2020. These data were also analyzed by macroregions of Brazil (North, Northeast, Southeast, South, and Midwest). The effect of the social distancing strategy on the increase of acute laryngitis, tracheitis, otitis media, and mastitis, as absolute and relative reductions, was calculated by analyzing the annual calculation of 2015-2019 vs 2020.

Results

All the hospitalizations compared in the Unified Health System (SUS) for laryngitis and acute tracheitis and otitis media decreased, considering all states of Brazil. The largest reduction in hospitalization reduction was in the North, with -94% in 2015-2019 vs 2020 in cases of laryngitis and acute tracheitis, and in the Midwest, with - 85% in 2015-2019 vs 2020 in cases of otitis media.

Conclusion

Hospitalizations for laryngitis, acute tracheitis, and acute otitis media in children <9 years old decreased between March and July 2020 in Brazil, when social distancing measures were adopted due to the COVID-19 pandemic.

Impact of non-pharmacological initiatives for COVID-19 on hospital admissions due to pediatric acute respiratory illnesses

INTRODUCTION

Interventions to deal with the COVID-19 pandemic may impact the burden of other respiratory diseases. The aim of this study is to analyze the impact of non-pharmacological initiatives (NPI) against COVID-19 on the number of hospitalizations due to pediatric acute respiratory illnesses (ARIs).

MATERIAL AND METHODS

This is a retrospective analysis of pediatric hospitalizations in Porto Alegre, Brazil. We analyzed the monthly incidence of hospital admissions from 2018 to 2020 due to ARIs included in the study. The time series was divided into the period before introducing NPI (2018 and 2019), and the period when NPI were running (2020). We compared means between the years with Student's t-test. The Dickey-Fuller test was used for secular trend analysis. For seasonality, Fischer's G test was performed. Dynamic linear univariate and multivariate models were used to estimate the association between the predictors (the introduction of NPI, secular trend, and seasonality) and outcome (the incidence of ARI admissions). For the statistical analysis, the cut-off probability for rejecting the null hypothesis was defined as <5%.

RESULTS

From 2018 to 2020, 10,109 hospital admissions were due to the respiratory causes included in this study. There was a significant decrease in 2020 in the mean incidence of the ARIs studied compared with 2018 and 2019. The number of hospitalizations due to respiratory diseases in children decreased by 64% for asthma and 93% for bronchiolitis. A secular trend of monthly admissions rates due to ARIs was only observed in the laryngotracheitis data (p = 0.485), but seasonality was detected in all analyses. According to the univariate and multivariate analysis, the introduction of NPI was associated with a decrease in the incidence of ARI admissions.

CONCLUSION

There was a significant reduction in hospital admissions due to ARIs in children. Our data suggest a significant impact of NPI on reducing the spread of viruses associated with ARIs in children. These results support respiratory illness prevention strategies.

Impact of nonpharmacological COVID-19 interventions in hospitalizations for childhood pneumonia in Brazil

BACKGROUND AND OBJECTIVE

The knowledge about the impact of the nonpharmacological measures to control the COVID-19 pandemic can give insight into ways in which they can also be applied for other respiratory diseases. To assess the impact of containment measures of the COVID-19 pandemic on pneumonia hospitalizations in children from 0 to 14 years of age in Brazil.

METHODS

Data from hospital admissions for pneumonia were obtained from the Department of Informatics of Brazilian Public Health System database in the period of 2015-2020 and analyzed by macroregions and age groups. To evaluate the effect of containment measures, on the incidence of pneumonia, the absolute reduction and relative reduction were calculated by analyzing the subsets 2015-2019 vs. 2020.

RESULTS

Comparing the subsets of April-August 2015-2019 vs. April-August 2020 for Brazil (total), there was an significant reduction in the average incidence of hospitalizations, with numbers ranging from -82% [IRR 0.17 (0.14-0.21)] for <4 years (prepandemic 741.8/100,000 vs. pandemic 132.7/100.000), -83% [IRR 0.17 (0.10-0.27)] for 5-9 years (prepandemic 113.6/100,000 vs. pandemic 19.6/100.000), -77% [IRR 0.23 (0.11-0.46)] for 10-14 (prepandemic 42.0/100,000 vs. pandemic 9.8/100.000) and -82% [IRR 0.18 (0.15-0.21)] for all children ≤14 years (prepandemic 897.4/100,000 vs. pandemic 162.1/100.000).

CONCLUSION

We found a significant decrease in cases of all cause pneumonia in children under 14 years and especially in the age group <9 years during the COVID-19 pandemic, which may be associated with the nonpharmacological measures applied to control the SARS-CoV-2.

Early Impact of Social Distancing in Response to Coronavirus Disease 2019 on Hospitalizations for Acute Bronchiolitis in Infants in Brazil

Background

Interventions to tackle the COVID-19 pandemic may affect the burden of other respiratory diseases. Considering the repercussion of these unique social experiences in infant’s health, this study aims to assess the early impact of social distancing due to the COVID-19 pandemic in hospital admissions for acute bronchiolitis.

Methods

Data from hospitalizations of acute bronchiolitis in infants under one year were obtained from the Department of Informatics of the Brazilian Public Health database (DATASUS) for the period between 2016 and 2020. These data were also analyzed by macro-regions of Brazil (North, Northeast, Southeast, South and Midwest). To evaluate the effect of social distancing strategy on the incidence of acute bronchiolitis, the absolute and relative reduction was calculated by analyzing the yearly subsets of 2016vs2020, 2017vs2020, 2018vs2020, and 2019vs2020.

Results

There was a significant reduction in all comparisons, ranging from -78% [IRR 0.22 (0.20 to 0.24)] in 2016vs2020 at -85% [IRR 0.15 (0.13 to 0.16)] in 2019vs2020, for the data from Brazil. For analyzes by macro-regions, the reduction varied from -58% [IRR 0.41 (0.37 to 0.45)] in the Midwest in 2016vs2020 to -93% [IRR 0.07 (0.06 to 0.08)] in the South in 2019vs2020.

Conclusions

There was a significant reduction in hospitalization for acute bronchiolitis in children under one year old, in Brazil, of the order of more than 70% for most analysis. Our data suggest an important impact of social distance on reducing the transmission of viruses related to acute bronchiolitis. Such knowledge may guide strategies for prevention of viruses spread.

Impact of pneumococcal conjugate vaccine on pneumonia hospitalization and mortality in children and elderly in Ecuador: Time series analyses

BACKGROUND

Pneumococcal conjugate vaccines (PCV) reduce the burden of invasive pneumococcal disease and pneumonia hospitalizations. However, there is limited evidence of the effect of PCVs on pneumonia mortality in children. It is anticipated that indirect effects resulting from PCV use among children might further reduce the remaining burden of adult pneumococcal disease caused by pneumococcal serotypes contained in PCV. Whether this will result in reduced pneumonia mortality in children and adults is still not known.

METHODS

We investigated the impact of PCV on pneumonia hospitalization and mortality in in Ecuador, where PCV was introduced in 2010, considering national data from secondary data sources from 2005 to 2015. Time series analysis using regression models were used to evaluate the decline in the number of all-cause pneumonia hospitalizations and deaths in the period post-PCV introduction. The target populations were children under 5 years and adults aged 50 years and over. Outcomes of interest were hospitalizations and mortality in which the main cause of hospital admission and death, respectively, were coded as ICD10 codes J12-18 (pneumonia). Three different models were fitted.

RESULTS

We demonstrate a sizeable impact of PCV in pneumonia hospitalization in children < 1 year (27% reduction, 95%CI 12-42%), and < 5 years of age (33% reduction, 95%CI 11-43%). The estimated impact of PCV in pneumonia mortality was a reduction of 14% in < 1 year (95%CI 0-33%), 10% in < 5 years (95%CI 0-25%), and 22% (95%CI 7-34%) in adults aged 50-64 years. Little evidence of a change was detected in elderly ≥ 65 years.

CONCLUSION

This study is the first to report on the impact of PCV in pneumonia morbidity and mortality in children and older adults, being relevant to policy makers and global donors. Findings were consistent when using different models. Additional studies on the indirect effect of PCV in older adults are needed.

Trends in all-cause pneumonia and otitis media in children aged <2 years following pneumococcal conjugate vaccine introduction in Colombia

In Colombia, pneumococcal conjugate vaccines (PCVs) were implemented into the infant universal mass vaccination program in a stepwise manner; PCV-7 between 2009 and 2011 in different geographic regions/cities, with nationwide introduction of a 10-valent vaccine (PHiD-CV) in 2012. We aimed to describe trends in all-cause pneumonia mortality and overall mortality, and in the incidence of all-cause pneumonia and otitis media (OM) in Colombian children <2 y (y = years) of age, before and after PCV introduction. We obtained mortality and incidence data, nationally and for five major cities (Bogota, Medellin, Barranquilla, Cali and Cartagena) from 2005–2016 and 2008–2016, respectively, comparing mortality and incidence proportions in the post-PCV introduction period with those in the pre-PCV period. Overall mean reductions in all-cause pneumonia mortality was observed in the post-PCV period nationally (48.8%; 95%CI: 45.5–51.8%) and in four cities including Bogota (77.1%; 71.1–81.8%) and Medellin (56.4%; 44.1–65.9%); no substantial reduction was observed in Cartagena. Similar findings were observed for overall mortality. Reductions in all-cause pneumonia incidence were observed in Bogota (66.0%; 65.5–66.6%), Medellin (40.6%; 39.3–41.9%) and Cartagena (15.0%; 11.2–18.6%), while incidence increased in Barranquilla (78.5%; 68.4–89.2%) and Cali (125.5%; 119.2–132.0%). All-cause OM incidence fell in Medellin and Bogota (42.1–51.1%) but increased (95.8%) in Barranquilla. In conclusion, overall reductions in disease outcomes were observed following PCV introduction in most cities and nationwide. Decreasing trends in outcomes were observed prior to PCV introduction, and limited data points and data reporting issues may have influenced our results. (ClinicalTrials.gov: NCT02567747)

Impact of maternal dTpa vaccination on the incidence of pertussis in young infants

Introduction

Pertussis is an important public health problem worldwide, especially in infants. An increase in the incidence in many countries occurred after 2010, including Brazil. In 2013, dTpa vaccine was introduced in the Brazil national immunization schedule of pregnant women. The objective of this study was to evaluate the national trends in the incidence of pertussis in Brazil in children under 1 year old, and the impact of the introduction of dTpa vaccine during pregnancy.

Methods

The incidence of hospitalizations and non-hospitalized confirmed cases of pertussis in neonates (< 1 month age) and young infants (1 month—< 1 year age) were analyzed, comparing the incidence in pre maternal vaccination (2011–2013) with the post-vaccination (2015–2017). We used non-respiratory hospitalizations as comparison, during the same period. A database of the Brazilian Ministry of Health (DATASUS) was used to analyze cases from 2007 to 2017 and the subsets of 2011–2013 and 2015–2017, after Pertussis resurgence. The vaccination data was accessed through the link of the Information System of the National Immunization Program (pni.datasus.gov.br).

Results

Between 2007 and 2017, 17,818 children under one year of age were hospitalized due to pertussis in Brazil. In the pre maternal vaccination period 2011–2013, the mean annual incidence of non-hospitalized confirmed cases of pertussis in children under 1 month was 722.2 / 100,000 and in the period of 2015–2017 the average was 377.3 / 100,000, representing a decrease of 47.7% [IRR 0.52 (0.46–0.59)]. At those periods of time, the average incidence per year for children of one month—< 1 year aged was 64.9 / 100,000 (2011–2013) and 29.3 / 100,000 (2015–2017) [IRR 0.45 (CI 0.29–0.69)].

Conclusion

Vaccination of pregnant woman coincides with the reduction in the number of cases of pertussis in children under 1 month of age from 2015. Immunization of pregnant woman seems to have an important impact on the prevention of the disease in young infants who have not yet received their own pertussis vaccine.

Invasive pneumococcal disease among hospitalized children in Brazil before and after the introduction of a pneumococcal conjugate vaccine

BACKGROUND

Most of the available data on invasive pneumococcal disease in Latin America are derived from laboratory-based surveillance systems. There is a lack of epidemiological data on the disease severity and mortality from hospitalized patients with pneumococcal infection.

METHODS

In this hospital-based retrospective historical series of hospitalized children with laboratory-confirmed IPD, we evaluated changes in disease episodes, in-hospital fatality rates, and need for intensive care unit admission after the inclusion of PCV10 in the Brazilian vaccination schedule. Invasive pneumococcal strains isolated by culture were serotyped. Changes over time were assessed, and pre-vaccination (2005-2009) to post-vaccination (2011-2015) disease rates and serotypes were compared.

RESULTS

260 patients with IPD and positive pneumococcal isolates were identified (198 during the pre-PCV10 period). When comparing both periods, hospitalizations were reduced from 20 cases to 5 cases per 10,000 pediatric admissions (p < 0.0001). Likewise, fatalities reduced from 6.6 to 2.0 cases per 10,000 pediatric admissions (p < 0.0001). Pneumonia was the most frequent clinical diagnosis (58%) - of which 49.6% had pleural effusion - followed by meningitis (22%) and bacteremia (15.9%). Overall 30% of cases were sent to ICU, with no percentual changes after PCV10. Additional PCV13 serotypes increased from 7% before vaccine introduction to 21% after PCV10 use. Similarly, serotypes not included in PCV13 increased from 11% to 29%.

CONCLUSIONS

There was a significant reduction in the hospitalizations rates, ICU admissions, and fatalities due to IPD after PCV10 introduction in Brazil. Cases due to PCV10 serotypes were reduced, while infections rates caused by non-PCV10 serotypes increased.

Effectiveness and impact of the 10-valent pneumococcal conjugate vaccine, PHiD-CV: review of clinical trials and post-marketing experience

INTRODUCTION

Pneumococcal diseases (including septicemia, meningitis, pneumonia, and upper respiratory infections) constitute a major public health problem. The World Health Organization recommends pneumococcal conjugate vaccine immunization of young children worldwide.

AREAS COVERED

We reviewed evidence on the effects of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV), which is used in childhood immunization programs in over 45 countries or regions. The effectiveness of PHiD-CV against invasive pneumococcal disease (IPD), pneumonia, and acute otitis media was assessed. We also present its effect on pneumococcal nasopharyngeal carriage (NPC) and indirect effects (herd protection) among unvaccinated individuals.

EXPERT COMMENTARY

Results from randomized, double-blind trials and post-marketing studies in various countries provide evidence of the protective efficacy, effectiveness, and impact of PHiD-CV against pneumococcal diseases. Data from different geographic locations also show reductions in NPC of vaccine pneumococcal serotypes, laying the foundation for indirect protection against pneumococcal disease. In countries where PHiD-CV is included in childhood immunization programs, there are signs of herd protection for vaccine serotypes among unvaccinated individuals. Although increases in non-vaccine serotype IPD and NPC rates were observed, there was an overall reduction of pneumococcal disease.

Theoretical pneumococcal vaccine coverage: analysis of serotypes isolated from inpatients at a tertiary care hospital

Objective:

To evaluate Streptococcus pneumoniae serotypes isolated from an inpatient population at a tertiary care hospital, in order to determine the theoretical coverage of the 13-valent pneumococcal conjugate vaccine (PCV13) and the 23-valent pneumococcal polysaccharide vaccine (PPV23).

Methods:

This was a cross-sectional study involving 118 inpatients at the Hospital São Lucas, in the city of Porto Alegre, Brazil, whose cultures of blood, cerebrospinal fluid, or other sterile body fluid specimens, collected between January 2005 and December 2016, yielded pneumococcal isolates. The theoretical vaccine coverage was studied in relation to the serotypes identified in the sample and their relationship with those contained in the pneumococcal vaccines available in Brazil.

Results:

The majority of the population was male (n = 66; 55.9%), with a median age of 57 years (interquartile range: 33-72 years). The most common manifestation was pneumonia, and the pneumococcus was most commonly isolated from blood cultures. More than one fourth of the study population had some degree of immunosuppression (n = 34; 28.8%). Of the total sample, 39 patients (33.1%) died. There were no significant associations between mortality and comorbidity type, ICU admission, or need for mechanical ventilation. The theoretical vaccine coverage of PPV23 alone and PCV13 plus PPV23 was 31.4% and 50.8%, respectively.

Conclusions:

If the patients in this sample had been previously vaccinated with PCV13 plus PPV23, theoretically, 50.8% of the cases of invasive pneumococcal disease that required hospital admission could potentially have been prevented. Invasive pneumococcal disease should be prevented by vaccination not only of children and the elderly but also of adults in their economically productive years, so as to reduce the socioeconomic costs, morbidity, and mortality still associated with the disease, especially in underdeveloped countries.

Cost-Effectiveness Analysis of Pneumococcal and Influenza Vaccines Administered to Children Less Than 5 Years of Age in a Low-Income District of Bogota, Colombia

BACKGROUND

The Colombian health authorities introduced the pneumococcal conjugated vaccine and the seasonal influenza vaccine into the national immunization schedule for children in 2009 and 2007, respectively. Despite this, the health authorities continue to be concerned about the high economic and disease burden among children from low-income households caused by these vaccine-preventable diseases.

OBJECTIVES

1) To evaluate the potential health outcomes of four vaccination strategies for subsidized children younger than 5 years in a low-income district in Colombia from a public, direct medical health care perspective. 2) To perform univariate, multivariate, and probabilistic sensitivity analysis to evaluate the robustness of these results.

METHODS

We built a Markov deterministic cohort model to evaluate five consecutive cohorts across four alternative situations: 1) no vaccination; 2) vaccination with the 10-valent pneumococcal conjugate vaccine (PCV10 vaccine); 3) vaccination with the trivalent inactivated vaccine (TIV) annually; and 4) combined vaccination with PCV10 vaccine and TIV.

RESULTS

The introduction of PCV10 vaccine and TIV and their combined use in particular would be highly cost-effective in comparison to no vaccination. For the combined vaccination with PCV10 vaccine and TIV, the incremental cost-effectiveness ratio would be $1,280 per disability-adjusted life-year (DALY) averted, the total incremental cost of the vaccination program would be $776,800, and it would avert four deaths and 332 DALYs for the five cohorts.

CONCLUSIONS

The introduction of PCV10 vaccine and TIV would be highly cost-effective from a public, direct medical health care perspective. Despite these results, we have not observed decreases in severity or hospitalizations. Our findings highlight the need for further studies of the immunization campaign indicators and socioeconomic indicators for this low-income community.

Frequency of Acute Otitis Media in Children Under 24 Months of Age Before and After the Introduction of the 10-valent Pneumococcal Conjugate Vaccine Into the National Immunization Program in Chile

BACKGROUND

Streptococcus pneumoniae is the leading cause of acute otitis media (AOM). Ten-valent pneumococcal conjugated vaccine (PCV-10) was introduced to the Chilean National Immunization Program (NIP) in 2011. The aim of this study was to estimate the frequency of AOM in children <24 months of age attending the emergency department (ED) of Hospital Sótero del Río (HSR) 4 years before and 4 years after the introduction of PCV-10 in the Chilean NIP.

METHODS

Register-based nested case-control study. Cases (n = 1907) were all children <24 months of age with a clinical diagnosis discharge of AOM at the ED of HSR, and controls (n = 244,334) were all other children <24 months of age attended at the same ED in the same time period, with any other discharge diagnosis. The data were obtained through HSR Statistical Service.

RESULTS

In the study period, there was a mean of 30,695 children <24 months managed each year at the ED of HSR. The percentage with AOM in the prevaccine period was 0.94% and in the postvaccine period was 0.62%, respectively (P = 0.026). Exposure to the PCV-10 was associated with a decreased risk to develop AOM in children <24 months, with an odds ratio of 0.659 (95% confidence interval: 0.60-0.72).

CONCLUSIONS

Our study showed a significant decrease in the percentage and risk of AOM in children <24 months of age who visited the ED of HSR after implementation of PCV-10 in the NIP in Chile.

Early impact of universal varicella vaccination on childhood varicella and herpes zoster hospitalizations in Brazil

INTRODUCTION

The Brazilian childhood National Immunization Program (NIP) introduced live and attenuated varicella vaccination in a single dose, combined as tetraviral vaccine, at 15 months of age in the whole country, during September to December of 2013. The aim of this study was to report trends in incidence of childhood hospital admissions related to varicella and zoster in Brazil from 2003 to 2016, including the first three years after vaccine introduction.

METHODS

The number and incidence of hospital admission in patients aged less than 20 years in Brazilian public health system with an admission diagnosis of varicella and zoster from 2003 to 2016 were analyzed and pre (2003-2013) and post-vaccination periods (2014-2016) were compared. The data were obtained from DATASUS, a Brazilian government's open-access public health database system, and analyzed adjusting for secular trend and seasonality if a statistically significant change was found.

RESULTS

During the study period, 69,791 admissions due to varicella and herpes zoster occurred in the children younger than 20 years. After adjusting for seasonality, the incidence of hospitalizations decreased from 27.33 to 14.33 per 100000 per year, which corresponds to a reduction of 47.6% (95% confidence interval 18.19-77.04%, p < 0.001) in the vaccinated age group (1-4 years) in 2014-2016 compared to pre-vaccination period. The changes were not significant in the unvaccinated age groups.

CONCLUSION

The hospitalizations due to varicella and herpes zoster were decreased by half early after the introduction of a single dose of tetraviral vaccine in NIP in the vaccinated children. Further studies may assess duration and intensity of this effect, as well as the indirect effect in the unvaccinated age groups.

Combined effect of PCV10 and meningococcal C conjugate vaccination on meningitis mortality among children under five years of age in Brazil

The 10-valent pneumococcal conjugate vaccine (PCV10) was introduced in the Brazilian National Immunization Program in March 2010, scheduled at 2, 4, and 6 months, with a booster at 12-15 months of age. The meningococcal C conjugate vaccine (MCC) was introduced in November 2010, scheduled at 3 and 5 months, with a booster dose at 12-15 months of age and no catch-up for older age groups. In this interrupted time-series analysis study, we used Brazilian mortality data from 2005 to 2015 for children under five years of age (excluding data from the state of Bahia) to assess the combined impact of these vaccines on the overall burden of meningitis mortality among children aged 0-23 months and 2-4 years, as defined using meningitis and meningococcemia specific International Classification of Diseases - tenth revision codes. Secular trends and seasonality were taken into account. We found significant reductions for both age groups relative to those observed for the comparison group of diseases, with immediate effects after the transition period (2010-2011) of 29.2% and 27.5% for children aged 0-23 months and 2-4 years, respectively. These immediate effects were sustained throughout the post-vaccination period (2012-2015). In total, 337 deaths were averted by the combined effect of both vaccines, 238 (95%CI 169-319) for children aged 0-23 months and 99 (95%CI 56-144) for those aged 2-4 years. These results add strong evidence in support of investments in these vaccines by low and middle-income countries.

Burden of hospitalized childhood community-acquired pneumonia: A retrospective cross-sectional study in Vietnam, Malaysia, Indonesia and the Republic of Korea

BACKGROUND

Few studies describe the community-acquired pneumonia (CAP) burden in children in Asia. We estimated the proportion of all CAP hospitalizations in children from nine hospitals across the Republic of Korea (high-income), Indonesia, Malaysia (middle-income), and Vietnam (low/middle-income).

METHODS

Over a one or two-year period, children <5 years hospitalized with CAP were identified using ICD-10 discharge codes. Cases were matched to standardized definitions of suspected (S-CAP), confirmed (C-CAP), or bacterial CAP (B-CAP) used in a pneumococcal conjugate vaccine efficacy study (COMPAS). Median total direct medical costs of CAP-related hospitalizations were calculated.

RESULTS

Vietnam (three centers): 7591 CAP episodes were identified with 4.3% (95% confidence interval 4.2;4.4) S-CAP, 3.3% (3.2;3.4) C-CAP and 1.4% (1.3;1.4) B-CAP episodes of all-cause hospitalization in children aged <5 years. The B-CAP case fatality rate (CFR) was 1.3%. Malaysia (two centers): 1027 CAP episodes were identified with 2.7% (2.6;2.9); 2.6% (2.4;2.8); 0.04% (0.04;0.1) due to S-CAP, C-CAP, and B-CAP, respectively. One child with B-CAP died. Indonesia (one center): 960 CAP episodes identified with 18.0% (17.0;19.1); 16.8% (15.8;17.9); 0.3% (0.2;0.4) due to S-CAP, C-CAP, and B-CAP, respectively. The B-CAP CFR was 20%. Korea (three centers): 3151 CAP episodes were identified with 21.1% (20.4;21.7); 11.8% (11.2;12.3); 2.4% (2.1;2.7) due to S-CAP, C-CAP, and B-CAP, respectively. There were no deaths.

COSTS

CAP-related hospitalization costs were highest for B-CAP episodes: 145.00 (Vietnam) to 1013.3 USD (Korea) per episode.

CONCLUSION

CAP hospitalization causes an important health and cost burden in all four countries studied (NMRR-12-50-10793).

Impact of the introduction of pneumococcal conjugate vaccination on pneumonia in The Gambia: population-based surveillance and case-control studies

BACKGROUND

Pneumococcal conjugate vaccines (PCVs) are used in many low-income countries but their impact on the incidence of pneumonia is unclear. The Gambia introduced PCV7 in August, 2009, and PCV13 in May, 2011. We aimed to measure the impact of the introduction of these vaccines on pneumonia incidence.

METHODS

We did population-based surveillance and case-control studies. The primary endpoint was WHO-defined radiological pneumonia with pulmonary consolidation. Population-based surveillance was for suspected pneumonia in children aged 2-59 months (minimum age 3 months in the case-control study) between May 12, 2008, and Dec 31, 2015. Surveillance for the impact study was limited to the Basse Health and Demographic Surveillance System (BHDSS), whereas surveillance for the case-control study included both the BHDSS and Fuladu West Health and Demographic Surveillance System. Nurses screened all outpatients and inpatients at all health facilities in the surveillance area using standardised criteria for referral to clinicians in Basse and Bansang. These clinicians recorded clinical findings and applied standardised criteria to identify patients with suspected pneumonia. We compared the incidence of pneumonia during the baseline period (May 12, 2008, to May 11, 2010) and the PCV13 period (Jan 1, 2014, to Dec 31, 2015). We also investigated the effectiveness of PCV13 using case-control methods between Sept 12, 2011, and Sept 31, 2014. Controls were aged 90 days or older, and were eligible to have received at least one dose of PCV13; cases had the same eligibility criteria with the addition of having WHO-defined radiological pneumonia.

FINDINGS

We investigated 18 833 children with clinical pneumonia and identified 2156 cases of radiological pneumonia. Among children aged 2-11 months, the incidence of radiological pneumonia fell from 21·0 cases per 1000 person-years in the baseline period to 16·2 cases per 1000 person-years (23% decline, 95% CI 7-36) in 2014-15. In the 12-23 month age group, radiological pneumonia decreased from 15·3 to 10·9 cases per 1000 person-years (29% decline, 12-42). In children aged 2-4 years, incidence fell from 5·2 to 4·1 cases per 1000 person-years (22% decline, 1-39). Incidence of all clinical pneumonia increased by 4% (-1 to 8), but hospitalised cases declined by 8% (3-13). Pneumococcal pneumonia declined from 2·9 to 1·2 cases per 1000 person-years (58% decline, 22-77) in children aged 2-11 months and from 2·6 to 0·7 cases per 1000 person-years (75% decline, 47-88) in children aged 12-23 months. Hypoxic pneumonia fell from 13·1 to 5·7 cases per 1000 person-years (57% decline, 42-67) in children aged 2-11 months and from 6·8 to 1·9 cases per 1000 person-years (72% decline, 58-82) in children aged 12-23 months. In the case-control study, the best estimate of the effectiveness of three doses of PCV13 against radiological pneumonia was an adjusted odds ratio of 0·57 (0·30-1·08) in children aged 3-11 months and vaccine effectiveness increased with greater numbers of doses (p=0·026). The analysis in children aged 12 months and older was underpowered because there were few unvaccinated cases and controls.

INTERPRETATION

The introduction of PCV in The Gambia was associated with a moderate impact on the incidence of radiological pneumonia, a small reduction in cases of hospitalised pneumonia, and substantial reductions of pneumococcal and hypoxic pneumonia in young children. Low-income countries that introduce PCV13 with reasonable coverage can expect modest reductions in hospitalised cases of pneumonia and a marked impact on the incidence of severe childhood pneumonia.

FUNDING

GAVI's Pneumococcal vaccines Accelerated Development and Introduction Plan, Bill & Melinda Gates Foundation, and UK Medical Research Council.

Distribution of Streptococcus pneumoniae serotypes in the northeast macro-region of São Paulo state/Brazil after the introduction of conjugate vaccine

BACKGROUND

Infections caused by Streptococcus pneumoniae (Spn) still challenge health systems around the world, even with advances in vaccination programs. The present study evaluated the frequency of various Spn serotypes isolated in Regional Health Care Network 13 (RRAS 13), which includes the regional health departments (RHDs) of Araraquara, Barretos, Franca and Ribeirão Preto, especially after the introduction of 10-valent pneumococcal conjugate vaccine (PCV10) in 2010.

METHODS

The analyzed Spn strains were isolated from patients with invasive pneumococcal diseases (IPDs) and then sent to Adolfo Lutz Institute (ALI) for further confirmative identification tests during the period from 1998 to 2013. The samples were from the cities in RRAS13, which is located in the Northeast region of São Paulo State, and totals 90 municipalities.

RESULTS

We analyzed strains isolated from 796 patients. They were predominantly: men (58.9%); 20 to 60 years old (32.2%); evaluated from 2003 to 2010 (60.2%); and diagnosed with meningitis (45.7%) and pneumonia (45.0%), the most common invasive pneumococcal diseases. In 2010, serotypes 3, 19F, 1, 23F, 6A and 6B were among the most frequent, while serotypes 3, 12F, 14, 6A, 18C, 8 and 6B were more common after the introduction of PCV10. Serotypes 14, 19F and 3 were more frequent in meningitis, while serotypes 14, 3 and 1 prevailed in pneumonia. After 2010, there was a decrease in serotypes 14, 1, 23F and 5 and an increase in serotypes 3, 12F, 11A and 8, which were not present in the vaccine.

CONCLUSIONS

The present study noted the increase in serotypes 3, 12F, 11A and 8 after vaccination. None of those serotypes are included in the available conjugate vaccines, which highlights the importance of continued monitoring of IPDs in order to measure the disease burden in the population in the long term and provide new epidemiological information to determine the impact of PCV10 in Brazil.

Pneumococcal vaccination: Direct and herd effect on carriage of vaccine types and antibiotic resistance in Icelandic children

BACKGROUND

Since the introduction of pneumococcal conjugate vaccines, vaccine type pneumococcal carriage and disease has decreased world-wide. The aim was to monitor changes in the nasopharyngeal carriage of pneumococci, the distribution of serotypes and antimicrobial resistance in children before and after initiation of the 10-valent pneumococcal vaccination in 2011, in a previously unvaccinated population.

METHODS

Repeated cross-sectional study at 15day-care centres in greater Reykjavik area. Nasopharyngeal swabs were collected yearly in March from 2009 to 2015. The swabs were selectively cultured for pneumococci, which were serotyped using latex agglutination and/or PCR and antimicrobial susceptibility determined. Two independent studies were conducted. In study 1, on total impact, isolates from children aged <4years were included. The vaccine-eligible-cohort (birth-years: 2011-2013, sampled in 2013-2015) was compared with children at the same age born in 2005-2010 and sampled in 2009-2012. In study 2 on herd effect, isolates from older non-vaccine-eligible children (3.5-6.3years) were compared for the periods before and after the vaccination (2009-2011 vs 2013-2015. Vaccine impact was determined using 1-odds-ratio.

RESULTS

Following vaccination, the vaccine impact on vaccine type acquisition was 94% (95% CI: 91-96%) in study 1 and 56% (95% CI: 44-65%) in study 2. The impact on serotype 6A was 33% (95% CI: -9%; 59%) in study 1 and 42% (95% CI: 10-63%) in study 2 with minimal effect on 19A. The non-vaccine serotypes/groups 6C, 11, 15 and 23B were the most common serotypes/groups after vaccination. Isolates from the vaccine-eligible-cohort had lower penicillin MICs, less resistance to erythromycin and co-trimoxazole and less multi resistance than isolates from the control-group.

CONCLUSIONS

The efficacy of the vaccination on vaccine serotypes was high, and a milder effect on vaccine-associated-serotype 6A was observed for the vaccine-eligible-cohort. There was a significant herd effect on vaccine types in older non-vaccine-eligible children. Overall antimicrobial non-susceptibility was reduced.

Pneumococcal conjugate vaccines and hospitalization of children for pneumonia: a time-series analysis, South Africa, 2006-2014

OBJECTIVE

To assess the impact of immunization with pneumococcal conjugate vaccines on all-cause pneumonia hospitalizations among children in Soweto, South Africa.

METHODS

We used data collected at the Chris Hani Baragwanath Hospital in Soweto between 2006 and 2014 - i.e. before and after April 2009, when a pneumococcal conjugate vaccine was first included in South Africa's routine immunization programme. Using a Bayesian generalized seasonal autoregressive moving-average model and the data collected in 2006-2008, we estimated the numbers of children that would have been hospitalized for pneumonia between 2010 and 2014 if no pneumococcal conjugate vaccines had been used. These estimates were then compared with the corresponding numbers of hospitalizations observed.

FINDINGS

Between 2006 and 2014, 26 778 children younger than five years - including 3388 known to be infected with human immunodeficiency virus (HIV) - were admitted to the study hospital for pneumonia. We estimated that, for the children known to be infected with HIV and for the other children, pneumococcal conjugate vaccines reduced the numbers of hospitalizations for pneumonia in 2014 by 33% (50% credible interval, CrI: 6 to 52) and 39% (50% CrI: 24 to 50), respectively. In the study hospital in 2012-2014, as a result of immunizations with these vaccines, there were an estimated 3100 fewer pneumonia hospitalizations of children younger than five years.

CONCLUSION

In our study hospital, following the introduction of pneumococcal conjugate vaccines into the national immunization programme, there were significant reductions in pneumonia hospitalizations among children.

Reduction in all-cause otitis media-related outpatient visits in children after PCV10 introduction in Brazil

Few studies have reported the effect of 10-valent pneumococcal conjugate vaccine (PCV10) on otitis media (OM) in infants. In particular, no population-based study in upper-middle income countries is available. In 2010, Brazil introduced PCV10 into its routine National Immunization Program using a 3+1 schedule. We measured the impact of PCV10 on all-cause OM in children. An interrupted time-series analysis was conducted in Goiânia/Brazil considering monthly rates (per 100,000) of all-cause OM outpatient visits in children aged 2–23 months. We used case-based data from the Outpatient Visits Information System of the Unified Health System coded for ICD-10 diagnosis for the period of August/2008 to July/2015. As a comparator, we used rates of outpatient visits due to all-other causes. The relative reduction of all-cause OM and all-other causes of outpatient visits were calculated as the difference between the predicted and observed cumulative rates of the PCV10 post-vaccination period. We then subtracted the relative reduction of all-other causes of outpatient visits from all-cause OM to obtain the impact of PCV10 on OM. In total, 6,401 OM outpatient visits were recorded in 4,793 children aged 2–23 months. Of these, 922 (19.2%) children had more than one OM episode. A significant reduction in all-cause OM visits was observed (50.7%; 95%CI: 42.2–59.2%; p = 0.013), while the reduction in visits due to all-other causes was 7.7% (95% CI 0.8–14.7%; p<0.001). The impact of PCV10 on all-cause OM was thus estimated at 43.0% (95%CI 41.4–44.5). This is the first study to show significant PCV10 impact on OM outpatient visits in infants in a developing country. Our findings corroborate the available evidence from developed countries.

A prospective observational cohort study to assess the incidence of acute otitis media among children 0-5 years of age in Southern Brazil

Objectives

To estimate acute otitis media incidence among young children and impact on quality of life of parents/caregivers in a southern Brazilian city.

Methods

Prospective cohort study including children 0–5 years of age registered at a private pediatric practice. Acute otitis media episodes diagnosed by a pediatrician and impact on quality of life of parents/caregivers were assessed during a 12-month follow-up.

Results

During September 2008–March 2010, of 1,136 children enrolled in the study, 1074 (95%) were followed: 55.0% were ≤2 years of age, 52.3% males, 94.7% white, and 69.2% had previously received pneumococcal vaccine in private clinics. Acute otitis media incidence per 1000 person-years was 95.7 (95% confidence interval: 77.2–117.4) overall, 105.5 (95% confidence interval: 78.3–139.0) in children ≤2 years of age and 63.6 (95% confidence interval: 43.2–90.3) in children 3–5 years of age. Acute otitis media incidence per 1000 person-years was 86.3 (95% confidence interval: 65.5–111.5) and 117.1 (95% confidence interval: 80.1–165.3) among vaccinated and unvaccinated children, respectively. Nearly 68.9% of parents reported worsening of their overall quality of life.

Conclusion

Acute otitis media incidence among unvaccinated children in our study may be useful as baseline data to assess impact of pneumococcal vaccine introduction in the Brazilian National Immunization Program in April 2010.

Hospitalizações de crianças por condições evitáveis no Estado do Paraná: causas e tendência

Resumo Objetivo Analisar a tendência das hospitalizações por condições sensíveis à atenção primária, segundo principais causas em menores de cinco anos. Métodos Estudo de séries temporais do tipo ecológico realizado com dados do Sistema de Informação Hospitalar do Estado do Paraná. A análise ocorreu a partir das taxas de hospitalização e de modelos de regressão polinomial segundo idade e causa. Resultados As causas mais frequentes foram pneumonias, gastrenterites, asma, infeção no rim e trato urinário e deficiências nutricionais. As hospitalizações por pneumonia, asma e deficiências nutricionais em menores de cinco anos reduziram e por gastroenterites mantiveram-se estáveis. Houve aumento nas taxas de hospitalização por infecção no rim e trato urinário em todas as idades. Conclusão A tendência de hospitalização por condições sensíveis em menores de cinco anos foi crescente apenas para as crianças menores de um ano. As hospitalizações por pneumonias, gastroenterites, asma e deficiências nutricionais apresentaram tendência decrescente.

Impact of ten-valent pneumococcal conjugate vaccine on pneumonia in Finnish children in a nation-wide population-based study

Background

The ten-valent pneumococcal conjugate vaccine (PCV10) was introduced into the Finnish National Vaccination Program (NVP) in September 2010 using a 2+1 schedule (3, 5, 12 months). We estimated the direct and indirect effects of PCV10 on pneumonia among children to evaluate the public health impact of the vaccine.

Methods

We conducted a nation-wide population-based, observational study comparing rates of pneumonia in children before and after the NVP introduction. For the total (direct and indirect) effect, the cohort of vaccine-eligible children (born June 1, 2010 or later) was followed until the end of 2013 (age range 3–42 months). For the indirect effect, a cohort of older children (age range 7–71 months) not eligible for the PCV vaccination was followed from 2011 to 2013. Both cohorts were compared with two season- and age-matched reference cohorts before NVP introduction. Hospitals’ in- and outpatient discharge notifications with ICD-10 diagnoses compatible with pneumonia (J10.0, J11.0, J12-J18, J85.1 or J86) as set by the hospital pediatricians were collected from the national Care Register. The main outcome was hospital-treated primary pneumonia (HTPP), defined as primary diagnosis of pneumonia after in-patient hospitalization. We compared rates of pneumonia in the NVP target and reference cohorts by using Poisson regression models.

Results

The rate of HTPP episodes was 5.3/1000 person-years in the combined reference cohorts and 4.1/1000 person-years in the target cohort vaccine-eligible children. Compared with the reference cohort, the relative rate reduction in target cohort was 23% (95%CI 18–28) and the absolute reduction 1.3/1000 person-years. In the indirect effect evaluation, we observed continued increase in HTPP incidence until 2011 with a subsequent reduction of 18% (95%CI 10–25) during years 2012 to 2013. Number of empyema diagnoses remained low.

Conclusions

A substantial decrease in pneumonia rates was observed both among vaccine-eligible children and among older, unvaccinated children after PCV10 introduction.

[Immunisation schedule of the Spanish Association of Paediatrics: 2015 recommendations]

The Advisory Committee on Vaccines of the Spanish Association of Paediatrics updates the immunisation schedule every year, taking into account epidemiological data as well as evidence on the safety, effectiveness and efficiency of current vaccines, including levels of recommendation. In our opinion, this is the optimal vaccination calendar for all children resident in Spain. Regarding the vaccines included in the official unified immunization schedule, the Committee emphasizes the administration of the first dose of hepatitis B either at birth or at 2 months of life; the recommendation of the first dose of MMR and varicella vaccine at the age of 12 months, with the second dose at the age of 2-3 years; DTaP or Tdap vaccine at the age of 6 years, followed by another Tdap booster dose at 11-12 years old; Tdap strategies for pregnant women and household contacts of the newborn, and immunization against human papillomavirus in girls aged 11-12 years old with a 2 dose scheme (0, 6 months). The Committee reasserts its recommendation to include vaccination against pneumococcal disease in the routine immunisation schedule, the same as it is being conducted in Western European countries. The recently authorised meningococcal B vaccine, currently blocked in Spain, exhibits the profile of a universal vaccine. The Committe insists on the need of having the vaccine available in communitary pharmacies. It has also proposed the free availability of varicella vaccines. Their efectiveness and safety have been confirmed when they are administred from the second year of life. Vaccination against rotavirus is recommended in all infants. The Committee stresses the need to vaccinate population groups considered at risk against influenza and hepatitis A.

Impact and Effectiveness of 10 and 13-Valent Pneumococcal Conjugate Vaccines on Hospitalization and Mortality in Children Aged Less than 5 Years in Latin American Countries: A Systematic Review

Background

Several Latin American and Caribbean (LAC) countries have introduced pneumococcal conjugate vaccine (PCV-10 or PCV-13) in their routine national immunization programs.

Objectives

We aimed to summarize the evidence of PCV impact and effectiveness in children under 5 years old in the LAC Region.

Methods

We conducted a systematic review of the literature on impact or effectiveness of PCVs on deaths or hospitalizations due to invasive pneumococcal disease (IPD), pneumonia, meningitis and sepsis. We searched Medline, WoS, Lilacs, Scopus, Central and gray literature published in any language from 2009 to January 2016. We included studies addressing the outcomes of interest in children in the target age group, and with the following designs: randomized trials, cohort or case-control, interrupted time series with at least three data points before and after the intervention, and before-after studies. Screening of citations, data extraction, and risk of bias assessment were conducted in duplicate by independent reviewers, according to the study protocol registered on PROSPERO. Descriptive analysis of the effectiveness measurements and sensitivity analysis were conducted. Effectiveness is reported as 1-OR or 1-RR for case control or cohort/clinical trials, and as percent change of disease incidence rates for before-after studies.

Results

We identified 1,085 citations, 892 from databases and 193 from other sources. Of these, 22 were further analyzed. Studies were from Brazil, Chile, Uruguay, Argentina, Peru and Nicaragua. Effectiveness ranged from 8.8–37.8% for hospitalizations due to X-ray confirmed pneumonia, 7.4–20.6% for clinical pneumonia, and 13.3–87.7% for meningitis hospitalizations, and 56–83.3% for IPD hospitalization, varying by age, outcome definition, type of vaccine and study design.

Conclusions

Available evidence to date indicates significant impact of both PCV-10 and PCV-13 in the outcomes studied, with no evidence of the superiority of one vaccine over the other on pneumonia, IPD or meningitis hospitalization reduction in children under 5 years old.

Challenges to estimating vaccine impact using hospitalization data

Because the real-world impact of new vaccines cannot be known before they are implemented in national programs, post-implementation studies at the population level are critical. Studies based on analysis of hospitalization rates of vaccine-preventable outcomes are typically used for this purpose. However, estimates of vaccine impact based on hospitalization data are particularly prone to confounding, as hospitalization rates are tightly linked to changes in the quality, access and use of the healthcare system, which often occur simultaneously with introduction of new vaccines. Here we illustrate how changes in healthcare delivery coincident with vaccine introduction can influence estimates of vaccine impact, using as an example reductions in infant pneumonia hospitalizations after introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) in Brazil. To this end, we explore the effect of changes in several metrics of quality and access to public healthcare on trends in hospitalization rates before (2008–09) and after (2011–12) PCV10 introduction in 2010. Changes in infant pneumonia hospitalization rates following vaccine introduction were significantly associated with concomitant changes in hospital capacity and the fraction of the population using public hospitals. Importantly, reduction of pneumonia hospitalization rates after PCV10 were also associated with the expansion of outpatient services in several Brazilian states, falling more sharply where primary care coverage and the number of health units offering basic and emergency care increased more. We show that adjustments for unrelated (non-vaccine) trends commonly employed by impact studies, such as use of single control outcomes, are not always sufficient for accurate impact assessment. We discuss several ways to identify and overcome such biases, including sensitivity analyses using different denominators to calculate hospitalizations rates and methods that track changes in the outpatient setting. Employing these practices can improve the accuracy of vaccine impact estimates, particularly in evolving healthcare settings typical of low- and middle-income countries.

Impact of the pneumococcal 10-valent vaccine on reducing hospitalization for community-acquired pneumonia in children

OBJECTIVE

To describe and analyze the occurrence of hospitalizations for community-acquired pneumonia in children before and after the pneumococcal 10-valent conjugate vaccine implementation into the National Immunization Program.

METHODS

This is an ecological study that includes records of children younger than one year old, vaccinated and not vaccinated with the pneumococcal 10-valent conjugate vaccine in the periods pre- and post-inclusion of the vaccine in the National Immunization Program in the area covered by the Regional Health Superintendence of Alfenas, state of Minas Gerais, Brazil. Vaccination was considered as the exposure factor and hospitalization for community-acquired pneumonia as the endpoint, using secondary annual data by municipality. The prevalence ratio and its 95% confidence interval (95%CI) were used to verify the association between variables. The Z test was used to calculate the difference between proportions.

RESULTS

Considering the 26 municipalities of the Regional Health Superintendence of Alfenas, there was a significant reduction in hospitalizations for community-acquired pneumonia in children younger than one year of age, with prevalence ratio (PR)=0.81 (95%CI: 0.74 to 0.89; p<0.05), indicating a 19% lower prevalence of hospitalization for community-acquired pneumonia in the post-vaccination period.

CONCLUSIONS

The results suggest the effectiveness of the pneumococcal 10-valent conjugate vaccine in preventing severe cases of community-acquired pneumonia in children younger than one year of age.

Impact of the pneumococcal 10-valent vaccine on reducing hospitalization for community-acquired pneumonia in children

OBJECTIVE

To describe and analyze the occurrence of hospitalizations for community-acquired pneumonia in children before and after the pneumococcal 10-valent conjugate vaccine implementation into the National Immunization Program.

METHODS

This is an ecological study that includes records of children younger than one year old, vaccinated and not vaccinated with the pneumococcal 10-valent conjugate vaccine in the periods pre- and post-inclusion of the vaccine in the National Immunization Program in the area covered by the Regional Health Superintendence of Alfenas, state of Minas Gerais, Brazil. Vaccination was considered as the exposure factor and hospitalization for community-acquired pneumonia as the endpoint, using secondary annual data by municipality. The prevalence ratio and its 95% confidence interval (95%CI) were used to verify the association between variables. The Z test was used to calculate the difference between proportions.

RESULTS

Considering the 26 municipalities of the Regional Health Superintendence of Alfenas, there was a significant reduction in hospitalizations for community-acquired pneumonia in children younger than one year of age, with prevalence ratio (PR)=0.81 (95%CI: 0.74 to 0.89; p<0.05), indicating a 19% lower prevalence of hospitalization for community-acquired pneumonia in the post-vaccination period.

CONCLUSIONS

The results suggest the effectiveness of the pneumococcal 10-valent conjugate vaccine in preventing severe cases of community-acquired pneumonia in children younger than one year of age.

[Immunisation schedule of the Spanish Association of Paediatrics: 2016 recommendations]

The Advisory Committee on Vaccines of the Spanish Association of Paediatrics (CAV-AEP) annually publishes the immunisation schedule which, in our opinion, estimates optimal for children resident in Spain, considering available evidence on current vaccines. We acknowledge the effort of the Ministry of Health during the last year in order to optimize the funded unified Spanish vaccination schedule, with the recent inclusion of pneumococcal and varicella vaccination in early infancy. Regarding the funded vaccines included in the official unified immunization schedule, taking into account available data, CAV-AEP recommends 2+1 strategy (2, 4 and 12 months) with hexavalent (DTPa-IPV-Hib-HB) vaccines and 13-valent pneumococcal conjugate vaccine. Administration of Tdap and poliomyelitis booster dose at the age of 6 is recommended, as well as Tdap vaccine for adolescents and pregnant women, between 27-36 weeks gestation. The two-dose scheme should be used for MMR (12 months and 2-4 years) and varicella (15 months and 2-4 years). Coverage of human papillomavirus vaccination in girls aged 11-12 with a two dose scheme (0, 6 months) should be improved. Information for male adolescents about potential beneficial effects of this immunisation should be provided as well. Regarding recommended unfunded immunisations, CAV-AEP recommends the administration of meningococcal B vaccine, due to the current availability in Spanish communitary pharmacies, with a 3+1 scheme (3, 5, 7 and 13-15 months). CAV-AEP requests the incorporation of this vaccine in the funded unified schedule. Vaccination against rotavirus is recommended in all infants. Annual influenza immunisation and vaccination against hepatitis A are indicated in population groups considered at risk.

The host immune dynamics of pneumococcal colonization: implications for novel vaccine development

The human nasopharynx (NP) microbiota is complex and diverse and Streptococcus pneumoniae (pneumococcus) is a frequent member. In the first few years of life, children experience maturation of their immune system thereby conferring homeostatic balance in which pneumococci are typically rendered as harmless colonizers in the upper respiratory environment. Pneumococcal carriage declines in many children before they acquire capsular-specific antibodies, suggesting a capsule antibody-independent mechanism of natural protection against pneumococcal carriage in early childhood. A child's immune system in the first few years of life is Th2-skewed so as to avoid inflammation-induced immunopathology. Understanding Th1/Th2 and Th17 ontogeny in early life and how adjuvant vaccine formulations shift the balance of T helper-cell differentiation, may facilitate the development of new protein-based pneumococcal vaccines. This article will discuss the immune dynamics of pneumococcal colonization in infants. The discussion aims to benefit the design and improvement of protein subunit-based next-generation pneumococcal vaccines.

Surveillance of the impact of pneumococcal conjugate vaccines in developing countries

Infection due to Streptococcus pneumoniae is a leading cause of morbidity and mortality in young children, especially in developing countries. With the support of Gavi, the Vaccine Alliance, the majority of these countries have introduced pneumococcal conjugate vaccines (PCV) into their national immunization programs and early data demonstrate a high degree of effectiveness, translating to enormous public health benefit through both direct and indirect (herd) effects. Future vaccination strategy may be focused on maintaining herd effects rather than individual protection. Evaluation of vaccine-type carriage, particularly in pneumonia cases, may be an easy, feasible way of measuring continued vaccine impact.

Cost-Effectiveness Analysis of Universal Vaccination of Adults Aged 60 Years with 23-Valent Pneumococcal Polysaccharide Vaccine versus Current Practice in Brazil

OBJECTIVE

To evaluate the cost-effectiveness of introducing universal vaccination of adults aged 60 years with the 23-valent pneumococcal polysaccharide vaccine (PPV23) into the National Immunization Program (NIP) in Brazil.

METHODS

Economic evaluation using a Markov model to compare two strategies: (1) universal vaccination of adults aged 60 years with one dose of PPV23 and 2) current practice (vaccination of institutionalized elderly and elderly with underlying diseases). The perspective was from the health system and society. Temporal horizon was 10 years. Discount rate of 5% was applied to costs and benefits. Clinical syndromes of interest were invasive pneumococcal disease (IPD) including meningitis, sepsis and others and pneumonia. Vaccine efficacy against IPD was obtained from a meta-analysis of randomized control trials and randomized studies, whereas vaccine effectiveness against pneumonia was obtained from cohort studies. Resource utilization and costs were obtained from the Brazilian Health Information Systems. The primary outcome was cost per life year saved (LYS). Univariate and multivariate sensitivity analysis were performed.

RESULTS

The universal vaccination strategy avoided 7,810 hospitalizations and 514 deaths, saving 3,787 years of life and costing a total of USD$31,507,012 and USD$44,548,180, respectively, from the health system and societal perspective. The universal immunization would result in ICERs of USD$1,297 per LYS, from the perspective of the health system, and USD$904 per LYS, from the societal perspective.

CONCLUSION

The results suggest that universal vaccination of adults aged 60 years with the 23-valent pneumococcal polysaccharide vaccine (PPV23) is a very cost-effective intervention for preventing hospitalization and deaths for IPD and pneumonia is this age group in Brazil.

10-Valent pneumococcal non-typeable haemophilus influenzae protein D-conjugate vaccine: a review in infants and children

The 10-valent pneumococcal non-typeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) (Synflorix™) includes ten serotype-specific polysaccharides of Streptococcus pneumoniae, eight of which are conjugated individually to a nonlipidated cell-surface lipoprotein (protein D) of non-typeable H. influenzae and two of which are conjugated to nontoxic tetanus or diphtheria toxoid carrier proteins. This article provides an overview of the well-established immunogenicity of PHiD-CV, including functional immune responses and immunologic memory, as well as immune responses in preterm infants and HIV-infected children. It also includes a brief discussion of cross-protection against vaccine-related serotypes (6A and 19A) and focuses on labelling in the EU, where PHiD-CV is approved for active immunization against invasive disease, pneumonia, and acute otitis media (AOM) caused by S. pneumoniae in infants and young children up to 5 years of age. Evidence of the protective efficacy and effectiveness of PHiD-CV against pneumococcal diseases is available from several studies, including the randomized, double-blind trials COMPAS (Clinical Otitis Media and Pneumonia Study) and FinIP (Finnish Invasive Pneumococcal disease), as well as postmarketing studies from various countries. As would be expected, protection against pneumonia or AOM is substantially lower than that against invasive pneumococcal disease, as many micro-organisms other than pneumococcal vaccine serotypes can cause pneumonia and AOM, thereby limiting the overall protection of PHiD-CV against these diseases. PHiD-CV has a safety and reactogenicity profile similar to that of other pneumococcal conjugate vaccines.