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

A phase 3, single-arm, open-label study to evaluate the safety, tolerability, and immunogenicity of a 15-valent pneumococcal conjugate vaccine, V114, in a 3+1 regimen in healthy infants in South Korea (PNEU-PED-KOR)

There is an ongoing burden of pneumococcal disease in children despite the use of pneumococcal conjugate vaccines (PCVs). This phase 3, open-label, single-arm, multisite, descriptive study was designed to evaluate the safety and immunogenicity of a 3 + 1 regimen of V114 (VAXNEUVANCE™), a 15-valent PCV, in South Korean infants and toddlers. Adverse events (AEs) were reported for 14 d following any vaccination, and throughout the study period for serious AEs. Serotype-specific immunoglobulin G (IgG) response rates (proportion of participants meeting an IgG threshold value of ≥0.35 μg/mL) and geometric mean concentrations (GMCs) for the 15 serotypes at 30 d postdose 3 (PD3) and at 30 d postdose 4 (PD4) were evaluated as endpoints. Healthy infants enrolled at 42-90 d after birth were vaccinated with V114 (N = 57). The most commonly reported AEs were those solicited in the trial. The majority of reported AEs were transient and of mild or moderate intensity. Few serious AEs were reported; none were vaccine related. No participants died nor discontinued the study vaccine because of an AE. V114 was immunogenic for all 15 serotypes contained in the vaccine, as assessed by IgG response rates at 30 d PD3 and IgG GMCs at 30 d PD3 and at 30 d PD4. V114 was well tolerated and immunogenic when administered as a 3 + 1 regimen in healthy South Korean infants and toddlers.

Estimated Population-Level Impact of Pneumococcal Conjugate Vaccines Against All-Cause Pneumonia Mortality Among Unvaccinated in 5 Latin American Countries

BACKGROUND

Pneumococcal conjugate vaccines (PCVs) provide strong direct protection in children, while limited data are available on their indirect effect on mortality among older age groups. This multicountry study aimed to assess the population-level impact of pediatric PCVs on all-cause pneumonia mortality among children ≥5 years of age, and invasive pneumococcal disease (IPD) cases in Chile.

METHODS

Demographic and mortality data from Argentina, Brazil, Chile, Colombia, and Mexico were collected considering the ≥ 5-year-old population, from 2000 to 2019, with 1 795 789 deaths due to all-cause pneumonia. IPD cases in Chile were also evaluated. Time series models were employed to evaluate changes in all-cause pneumonia deaths during the postvaccination period, with other causes of death used as synthetic controls for unrelated temporal trends.

RESULTS

No significant change in death rates due to all-cause pneumonia was detected following PCV introduction among most age groups and countries. The proportion of IPD cases caused by vaccine serotypes decreased from 29% (2012) to 6% (2022) among people aged ≥65 years in Chile.

DISCUSSION

While an effect of PCV against pneumonia deaths (a broad clinical definition that may not be specific enough to measure indirect effects) was not detected, evidence of indirect PCV impact was observed among vaccine-type-specific IPD cases.

Pneumonia-Related Hospitalizations among the Elderly: A Retrospective Study in Northeast Italy

Background: In both the elderly and children, pneumonia remains one of the leading causes of hospitalization. This study aimed to assess the impact of pneumonia-related hospitalizations in the population over 65 years of age in the Veneto Region. Methods: This retrospective study analyzed hospital discharge records for patients aged 65 and older who resided in the Veneto Region and had a diagnosis of pneumonia from 2007 to 2023. The hospitalizations were identified using specific ICD-9-CM codes for pneumonia as a discharge diagnosis. Hospitalization rates, mortality rates, the prevalence of complications and comorbidities, the length of stay, and associated costs were calculated by age and year. Results: From 2007 to 2023, there were 139,201 hospitalizations for pneumonia. Emergency admissions accounted for 92.1% of these cases, and only 2.0% had a specific diagnosis of pneumococcal pneumonia. The median length of stay was 10 days, and the median diagnosis-related group (DRG) tariff per hospitalization was EUR 3307. Excluding the pandemic years, the hospitalization rates remained stable at approximately 850 cases per 100,000 inhabitants before 2019. After 2022, the rates started to increase again. Overall, in the investigated period, the results showed a negative trend (average Annual Percentage Change (AAPC) of -1.931, p < 0.0001). However, when only considering the pre-pandemic years, the trend was stable, while a decline was observed starting in 2020 (AAPC of -19.697, p = 0.001). The overall discharge mortality rates ranged from 13% to 19.3% but were significantly higher in those over 85 years of age (20.6% compared with 6.5% and 12.0% in the 65-74 and 75-84 age groups, respectively). Conclusions: This study highlights the substantial burden of pneumonia in individuals over 65 years of age, showing the impacts on public health.

Descriptive analysis of safety and immunogenicity profiles of a 15-valent pneumococcal conjugate vaccine between subcutaneous and intramuscular administration in a phase 1 study of healthy Japanese infants (V114-028)

INTRODUCTION

Subcutaneous (SC) administration is typically used for pediatric inactivated vaccines in Japan, whereas intramuscular (IM) administration is used outside Japan. We previously reported the safety and immunogenicity of V114, a 15-valent pneumococcal conjugate vaccine (PCV), administered subcutaneously and intramuscularly in a Japanese phase 1 study (V114-028). Here, we report secondary descriptive analyses on V114 groups of the study to further assess the safety and immunogenicity profiles of V114 between the administration routes.

METHODS

A total of 133 healthy Japanese infants were randomized to receive V114-SC (n = 44), V114-IM (n = 45), or PCV13-SC (n = 44) at approximately 3, 4, 5, and 12-15 months of age. Adverse events (AEs) from Days 1-14 post-vaccination and vaccine-related serious AEs from Day 1 to 1-month post-dose 4 were reported. Serotype-specific immunoglobulin G (IgG) responses were measured across the vaccination series.

RESULTS

Proportions of participants with solicited systemic AEs (irritability, somnolence, decreased appetite, and urticaria) and pyrexia were generally comparable between the groups. Compared with V114-SC, patients receiving V114-IM had a lower incidence of irritability and somnolence, and higher incidence of decreased appetite. Proportion of participants with solicited injection-site erythema was lower with V114-IM (82.2%) than V114-SC (100.0%). Those with other solicited injection-site AEs (induration, swelling, and pain) were generally comparable between the groups, with lower observed proportions with V114-IM. Serotype-specific IgG responses were also generally comparable between the groups, including at pre-toddler dose.

CONCLUSIONS

These results suggest the utility of IM administration as an option for V114 vaccination in Japanese infants.

Antiviral Activity of Angelica Tenuissima Nakai against Influenza A Virus

The influenza A virus poses a serious threat to human health and is an important global public health issue. The drugs currently used for treatment are becoming increasingly ineffective against influenza A viruses and require the development of new antiviral drugs. Angelica tenuissima Nakai (ATN), a traditional herbal medicine belonging to the Umbelliferae family, exhibits a broad range of pharmacological activities, including inflammation, headache, and cold symptoms. In the present study, based on target protein identification, functional enrichment analysis, and gene set comparisons, we first suggested that ATN has potential therapeutic effects against influenza A virus infection. Next, methylthiazol tetrazolium (MTT) and sulforhodamine B colorimetric (SRB) assay results revealed that ATN exhibited low cytotoxicity in Madin-Darby canine kidney (MDCK) cells. The antiviral properties of ATN were observed against H1N1 and H3N2 virus strains. Microscopy confirmed the increased survival rate of the host cells. Further time-of-addition experiments revealed that the addition of ATN before virus adsorption showed similar results to the whole period of treatment. The pre- and co-treated groups showed lower levels of viral RNA (M1 protein). The results of this study suggest that ATN exhibits antiviral properties against the influenza A virus. These therapeutic properties of ATN can serve as a theoretical basis for further research on the applicability of ATN in the development of antiviral agents.

Pediatric Pneumococcal Conjugate Vaccine and Dosing Schedule Perceptions Among Health Care Providers and Caregivers in Germany, France, Spain, and Greece

INTRODUCTION

Most European infant national immunization programs (NIPs) recommend pneumococcal conjugate vaccines (PCVs), which currently cover 10-15 serotypes administered in a three-dose schedule (two primary  plus one booster). Recently, a PCV covering 20 serotypes that is administered in a four-dose schedule (three primary plus one booster) was licensed.

METHODS

An online survey was administered to collect data from health care providers (HCPs) and caregivers of children aged 0-5 (including expectant mothers) in four European countries (Germany, France, Spain, and Greece). All caregiver respondents had a shared or full responsibility to make health decisions for their child. Data on opinions, perceptions, and openness to a change in childhood vaccination dosing schedules were collected, along with demographic information for HCPs as well as caregivers.

RESULTS

A total of 601 HCPs and 1954 caregivers were recruited across the four countries. Nearly all HCPs (93%) agreed that broader serotype coverage against pneumococcal disease for children is a significant unmet need, and 92% had a "sense of urgency" to vaccinate children. Both HCPs and caregivers were supportive of an additional PCV dose and doctor visit, assuming it provided at least 20% more serotype coverage than what is currently available. Caregivers strongly agreed on the importance of full vaccination for pneumococcal disease, even if an extra dose and visit to the doctor was required.

CONCLUSIONS

HCPs and caregivers were virtually unanimous in their support for a PCV with broader serotype coverage and showed a subsequent willingness to include an extra infant dose/visit. These results can help guide broader discussions regarding public health policy and vaccine administration in the context of important efforts to reduce the global disease burden associated with pneumococcal disease.

Indirect protection in adults ≥18 years of age from pediatric pneumococcal vaccination: a review

INTRODUCTION

Infant immunization programs using pneumococcal conjugate vaccines (PCVs) have reduced the rates of pneumococcal disease through direct vaccine-induced protection in vaccinated children and through indirect protection in non-vaccinated children and adults.

AREAS COVERED

This review summarizes current evidence on the indirect protection of adults conferred by pediatric pneumococcal vaccination, including the impact on invasive pneumococcal disease (IPD) incidence and mortality, pneumonia admissions, and nasopharyngeal carriage prevalence. Factors affecting indirect protection against IPD are also discussed.

EXPERT OPINION

Pediatric immunization with PCVs has substantially decreased vaccine-serotype IPD and pneumonia through indirect protection in both older (≥65 years of age) and younger adults, including those with underlying medical conditions. However, serotype replacement by non-vaccine serotypes, the persistence of some vaccine serotypes, and divergence of serotypes between children and adults have limited the impact of pediatric PCV programs on adult populations. Designing complementary vaccines that leverage indirect protection from pediatric immunization and target the most prevalent adult serotypes may be a preferred strategy to maximize the public health impact of pneumococcal vaccination.

Using LASSO Regression to Estimate the Population-Level Impact of Pneumococcal Conjugate Vaccines

Pneumococcal conjugate vaccines (PCVs) protect against diseases caused by Streptococcus pneumoniae, such as meningitis, bacteremia, and pneumonia. It is challenging to estimate their population-level impact due to the lack of a perfect control population and the subtleness of signals when the endpoint-such as all-cause pneumonia-is nonspecific. Here we present a new approach for estimating the impact of PCVs: using least absolute shrinkage and selection operator (LASSO) regression to select variables in a synthetic control model to predict the counterfactual outcome for vaccine impact inference. We first used a simulation study based on hospitalization data from Mexico (2000-2013) to test the performance of LASSO and established methods, including the synthetic control model with Bayesian variable selection (SC). We found that LASSO achieved accurate and precise estimation, even in complex simulation scenarios where the association between the outcome and all control variables was noncausal. We then applied LASSO to real-world hospitalization data from Chile (2001-2012), Ecuador (2001-2012), Mexico (2000-2013), and the United States (1996-2005), and found that it yielded estimates of vaccine impact similar to SC. The LASSO method is accurate and easily implementable and can be applied to study the impact of PCVs and other vaccines.

Reductions in Childhood Pneumonia Mortality After Vaccination in the United States

BACKGROUND

We aim to estimate the magnitude of the reduction in pneumococcal pneumonia and meningitis mortality after the mass introduction of pneumococcal conjugate vaccine (PCV)7 and PCV13 in children in the United States.

METHODS

We assessed the trends in mortality rates from pneumococcal pneumonia and meningitis, in the United States between 1994 and 2017. We fitted an interrupted time-series negative binomial regression model (adjusted by trend, seasonality, PCV7/PCV13 coverage, and H. influenzae type b vaccine coverage) to estimate the counterfactual rates without vaccination. We reported a percent reduction in mortality estimates relative to the projected no-vaccination scenario, using the formula 1 minus the incidence risk ratio, with 95% confidence intervals (CIs).

RESULTS

Between 1994 and 1999 (the prevaccination period), the all-cause pneumonia mortality rate for 0-1-month-old children was 2.55 per 100,00 pop., whereas for 2-11 months-old children, this rate was 0.82 deaths per 100,000 pop. During the PCV7-period in 0-59-month-old children in the United States, the adjusted reduction of all-cause pneumonia was 13% (95% CI: 4-21) and 19% (95% CI: 0-33) of all-cause meningitis For PCV13, the reductions in this age group were 21% (95% CI: 4-35) for all-cause pneumonia mortality and 22% (95% CI: -19 to 48) for all-cause meningitis mortality. PCV13 had greater reductions of all-cause pneumonia than PCV13 in 6-11-month-old infants.

CONCLUSIONS

The universal introduction of PCV7, and later PCV13, for children 0-59 months old in the United States was associated with decreases in mortality due to all-cause pneumonia.

Effect of reduced two-dose (1+1) schedule of 10 and 13-valent pneumococcal conjugate vaccines (SynflorixTM and Prevenar13TM)) on nasopharyngeal carriage and serotype-specific immune response in the first two years of life: Results from an open-labelled randomized controlled trial in Indian children

INTRODUCTION

This study aimed to assess the effect of a reduced dose regime (1 + 1) of PCV10 and PCV13 along with 3-dose regimes on pneumococcal vaccine-type (VT) carriage and immunogenicity in the first two years of life in PCV-naïve Indian children.

METHODS

A total of 805 healthy infants aged 6-8 weeks were randomised to 7 groups (n = 115). Six groups received Synflorix^TM(PCV10) or Prevenar13^TM(PCV13) in the following schedules: 3 + 0 (three primary at 6, 10, and 14 weeks); 2 + 1 (two primary 6 and 14 weeks with booster at 9 months; 1 + 1 (one primary at 14 weeks with booster at 9 months). The 7th group was a PCV-naïve control group. Nasopharyngeal swabs were collected at 6, 18 weeks, 9, 10, 15, and 18 months of age. Venous blood samples were collected at 18 weeks, 9, 10, and 18 months of age for assessment of sero-specific IgG antibodies. Additionally, functional activity using a serotype specific opsonophagocytic assay (OPA) was assessed at 10 and 18 months of age in a subset (20%) of participants.

RESULTS

All schedules of PCV13 showed significant 13VT carriage reduction in the second year of life as compared to control. At 15 months of age, PCV13 (1 + 1) showed 45 % reduction in 13VT-carriage compared to the control [OR = 0.55 (95% CI; 0.31-0.97), p= 0.038]. None of the PCV10 schedules showed significant reduction in 10VT carriage in the second year. Although not powered for these outcomes, at 18 months of age, 1 + 1 and 2 + 1 schedules of both vaccines demonstrated higher sero-responders for all serotypes, higher geometric mean concentrations (GMC) for all serotypes except 23F [with both vaccines], higher percent OPA responders and OPA geometric mean titres (GMT) compared to the 3 + 0 schedules for all serotypes.

CONCLUSION

The reduced dose schedule (1 + 1) of PCV13 results in significant VT-carriage reduction in the second year of life. Immune protection provided by 1 + 1 schedules of PCV10 and PCV13 in the second year of life is comparable to WHO-recommended 3-dose schedules.

Cost-effectiveness of the 13-valent pneumococcal conjugate vaccine compared to the 10-valent vaccine in children: predictive analysis in the Ecuadorian context

Objective

To evaluate the cost-effectiveness and economic impact of changing childhood vaccination from the 10-valent pneumococcal conjugate vaccine (PCV10) to the 13-valent pneumococcal conjugate vaccine (PCV13) in the context of the Ecuadorian health system.

Methods

A Markov model was developed based on a hypothetical cohort of children &lt;1 year old with a 2 + 1 vaccination schedule. The model incorporates the most impactful chronic sequelae of invasive pneumococcal disease: bilateral hearing loss, spasticity, neurological deficit, hydrocephalus and epilepsy. At the end of each annual Markov cycle, the children heal with/without sequelae or die. A time horizon of 5 years was considered. The analysis was done from the perspective of the Ministry of Health.

Key findings

Vaccination with PCV13 is cost-saving (US$ −2940/QALY) in relation to PCV10 considering indirect effects (‘herd effect’) of childhood vaccination over adult population (&gt;65 years). So, PCV13 reduces incident cases of IPD in this adult population by 27.8% compared to PCV10. Simulation of the model in a cohort of 100 000 children &lt;1 year old showed an incidence of 25 cases of IPD with PCV13 versus 40 cases with PCV10, that is, a reduction of 37.5%. A reduction compared to PCV10 in the incidence of pneumonia and meningitis of 30.2 and 57.1%, respectively, was demonstrated. PCV13 decreased mortality by 32% compared to PCV10.

Conclusions

Vaccination with PCV13 is cost-saving in the Ecuadorian health context and significantly reduces morbidity and mortality in children &lt;5 years and in adults &gt;65 years due to the herd effect. The probabilistic analysis showed consistency in the results.

Return on Investment of 10-Valent Pneumococcal Conjugate Vaccine in Ecuador From 2010 to 2030

OBJECTIVES

Ecuador introduced the pneumococcal conjugate vaccine in 2010. A recent time series analysis has demonstrated the impact of 10-valent pneumococcal conjugate vaccine (PCV10) on hospitalized pneumococcal disease in children. We leveraged these estimates to calculate the return on investment (ROI) of PCV10 in Ecuador from 2010 to 2030 at the national and regional levels.

METHODS

We used 2 approaches to estimate the economic benefits: (1) cost of illness, which includes treatment, transportation, and productivity loss averted, (2) and the value of statistical life, which reflects society's average willingness to pay to save one life. Costs of the immunization program include vaccine costs (doses, syringes, injection supplies) and immunization delivery costs (personnel, cold chain equipment and maintenance, transportation, distribution services, and other recurrent costs). We estimated the ROI by dividing the net benefits by costs.

RESULTS

The ROI using the cost-of-illness approach was slightly negative in the introduction year. From 2011 to 2020, we estimated the ROI to be 0.45 (0.15-0.73). For the future decade, the ROI is estimated at 0.37 (-0.03 to 1.03). Using the value-of-statistical-life approach, the ROI was 1.46 (0.82-2.17) in the introduction year. In the first decade, the ROI was 1.01 (0.49-1.60); in the second decade, the ROI fell to 0.83 (0.23-1.78).

CONCLUSIONS

The results of this study demonstrate the total economic benefits of PCV10 in Ecuador exceed immunization program costs after the introduction year. Estimates from this study will inform country policy makers and will contribute to efforts to mobilize resources for immunization.

Laboratory-based surveillance in Latin America: attributes and limitations in evaluation of pneumococcal vaccine impact

Disease surveillance data are needed to monitor trends in disease activity, inform decision-making in public health and evaluate disease prevention/control measures. The Sistema Regional de Vacunas (SIREVA) supports laboratory-based surveillance of invasive pneumococcal disease (IPD) in Latin American countries, providing information on identification, distribution, and anti-microbial susceptibility of pneumococcal strains. We estimated the proportion of pneumococcal meningitis and sepsis/bacteremia cases captured by SIREVA, by comparing the number of SIREVA-reported isolates in Argentina, Brazil, Chile, Colombia, Ecuador and Mexico with the estimated expected number of cases based on regional estimates of disease incidence. In all six countries, the number of isolates reported by SIREVA was consistently lower than the number of cases expected, across all years with data available. The proportion of SIREVA-reported isolates was highest in Chile (43–83%) and lowest in Mexico (1.4–3.5%). Passive surveillance systems such as SIREVA are important tools for monitoring circulating strains that could be related to pneumococcal disease, but our results show that SIREVA is likely to underestimate pneumococcal disease incidence. This under-reporting will limit the precision of surveillance data in monitoring changes in the incidence of IPD after vaccine introduction, and this should be considered when assessing the impact of vaccination programs.

What is the context?

Infectious disease surveillance is an important epidemiological tool to monitor the health of a population.

Surveillence can be used to detect trends in disease activity and to trigger disease control measures.

In Latin America, the SIREVA surveillance system monitors occurrence of bacterial pneumonia, sepsis/bacteremia and meningitis.

However, passive surveillence systems may understimate disease occurrence.

What is new?

We compared the number of isolates of invasive pneumococcal disease (IPD), specifically meningitis and sepsis/bacteremia, in children aged <5 years reported in SIREVA data in six countries in Latin America with the expected number of cases based on regional estimates of IPD incidence.

Our results show that the number of isolates reported by SIREVA was consistently lower than the estimated number of cases, across all six countries and all the years available.

The percent difference between SIREVA-reported isolates and estimated number of cases was variable between countries, ranging from 43-83% in chile to 1.4-3.5% in Mexico.

What is the impact?

Passive surveillance systems such as SIREVA are important tools for monitoring disease incidence, but they are likely to underestimate pneumococcal disease occrruence.

This under-reporting will limit the precision of surveillance data in monitoring changes in disease incidence after vaccine introduction, and this needs to be considered when assessing vaccine impact.

Incidence and Mortality Trends of Acute Gastroenteritis and Pneumococcal Disease in Children Following Universal Rotavirus and Pneumococcal Conjugate Vaccination in Ecuador

INTRODUCTION

Ecuador introduced routine infant rotavirus (RV) vaccination in 2008 and pneumococcal conjugate vaccination (PCV) in 2011 to manage disease and mortality in children caused by gastroenteritis (GE) and by pneumonia (PNE) and invasive pneumococcal disease (IPD), respectively.

METHODS

This retrospective ecological database study described vaccination coverage as well as the trends in incidence and mortality in the pre- versus post-vaccination periods and used time-trend analysis models to assess the impact of vaccination.

RESULTS

RV vaccination coverage of the second dose was between 79-97% from 2008 to 2016. GE incidence and mortality showed a declining trend before vaccination which continued in the post-vaccination period. The model estimated a statistically significant decrease of 72.4% for GE mortality and 51.2% for GE incidence in the post-vaccination period. PCV vaccination coverage remained above 80% (second dose) and 40% (third dose) after 2011. PNE mortality showed a declining trend before vaccination and a continued decline after vaccination, while PNE incidence was more variable (sharp increase from 2005-2009 then decrease and eventual stabilisation). The model estimated a statistically significant decline of 41.1% for PNE mortality and a stable PNE incidence in the post- versus pre-vaccination period. IPD incidence and mortality yearly data showed large variability by year and low numbers, making it difficult to discern a trend. The model estimated a statistically significant reduction of 51.1% for IPD mortality and 31.5% for IPD incidence in the post- versus pre-vaccination period.

CONCLUSION

After the first 9 years of routine RV vaccination and 6 years of routine PCV vaccination in Ecuador, significant decreases in incidence and mortality in children < 5 years of age due to GE and pneumococcal disease have been observed.