Effectiveness of the 10-valent pneumococcal conjugate vaccine among girls, boys, preterm and low-birth-weight infants - Results from a randomized, double-blind vaccine trial

Vaccination to Reduce Antimicrobial Resistance Burden-Data Gaps and Future Research

Antimicrobial resistance (AMR) poses an immediate danger to global health. If unaddressed, the current upsurge in AMR threatens to reverse the achievements in reducing the infectious disease-associated mortality and morbidity associated with antimicrobial treatment. Consequently, there is an urgent need for strategies to prevent or slow the progress of AMR. Vaccines potentially contribute both directly and indirectly to combating AMR. Modeling studies have indicated significant gains from vaccination in reducing AMR burdens for specific pathogens, reducing mortality/morbidity, and economic loss. However, quantifying the real impact of vaccines in these reductions is challenging because many of the study designs used to evaluate the contribution of vaccination programs are affected by significant background confounding, and potential selection and information bias. Here, we discuss challenges in assessing vaccine impact to reduce AMR burdens and suggest potential approaches for vaccine impact evaluation nested in vaccine trials.

An indirect treatment comparison (ITC) and matching-adjusted indirect comparison (MAIC) between a 15-valent (V114) and a 20-valent (PCV20) pneumococcal conjugate vaccine among healthy infants

OBJECTIVES

Immunogenicity between 15-valent V114 (PCV15) and 20-valent PCV20 pneumococcal conjugate vaccines in healthy infants is compared in an indirect treatment comparison and matching-adjusted indirect comparison. Hypotheses: immunogenicity of V114 is non-inferior to PCV20 for all PCV13 serotypes, and superior to PCV20 for serotype 3 based on lower bound margins.

METHODS

Two phase 3 pivotal studies on 3 + 1 pediatric vaccination schedule at age 2, 4, 6, and 12-15 months compared V114 (N = 858) to PCV13 (N = 856) and PCV20 (N = 1001) to PCV13 (N = 987). Infant's age and race in V114 study were matched to those in PCV20 study. Primary endpoints were serotype-specific Immunoglobulin G (IgG) response rate difference (RRD) 30 days post-dose (PD)3; IgG geometric mean concentration (GMC) ratios 30 days PD3 and PD4.

RESULTS

V114 was non-inferior (m a r g i n R R D >-10%-point; m a r g i n G M C r a t i o >0.5) to PCV20 (p-value <0.001) for all endpoints. V114 was superior (m a r g i n R R D >0%-point; m a r g i n G M C r a t i o >1.2) to PCV20 (p-value <0.001) for serotype 3: RRD was 34.5% (95%CI 27.9%-41.1%) PD3, and IgG GMC ratios were 2.39 (95%CI 2.12-2.68) PD3 and 2.15 (95%CI 1.90-2.41) PD4.

CONCLUSION

Immune response to V114 administered in a 3 + 1 schedule in healthy infants was considered non-inferior to PCV20 for all 13 PCV13 serotypes and superior for serotype 3 PD3 and PD4.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov identifiers NCT03893448, NCT04382326.

Effectiveness of 7-Valent Pneumococcal Conjugate Vaccine Against Invasive Pneumococcal Disease in Medically At-Risk Children in Australia: A Record Linkage Study

BACKGROUND

Children with chronic medical conditions are at higher risk of invasive pneumococcal disease (IPD), but little is known about the effectiveness of the primary course of pneumococcal conjugate vaccine (PCV) in these children.

METHODS

A cohort born in 2001-2004 from two Australian states and identified as medically at-risk (MAR) of IPD either using ICD-coded hospitalizations (with conditions of interest identified by 6 months of age) or linked perinatal data (for prematurity) were followed to age 5 years for notified IPD by serotype. We categorized fully vaccinated children as either receiving PCV dose 3 by <12 months of age or ≥1 PCV dose at ≥12 months of age. Cox proportional hazard modeling was used to estimate hazard ratios (HRs), adjusted for confounders, and vaccine effectiveness (VE) was estimated as (1-HR) × 100.

RESULTS

A total of 9220 children with MAR conditions had 53 episodes of IPD (43 vaccine-type); 4457 (48.3%) were unvaccinated and 4246 (46.1%) were fully vaccinated, with 1371 (32.3%) receiving dose 3 by 12 months and 2875 (67.7%) having ≥1 dose at ≥12 months. Estimated VE in fully vaccinated children was 85.9% (95% CI: 33.9-97.0) against vaccine-type IPD and 71.5% (95% CI: 26.6-88.9) against all-cause IPD.

CONCLUSION

This is the first population-based study evaluating the effectiveness of PCV in children with MAR conditions using record linkage. Our study provides evidence that the VE for vaccine-type and all-cause IPD in MAR children in Australia is high and not statistically different from previously reported estimates for the general population. This method can be replicated in other countries to evaluate VE in MAR children.

Pneumococcal conjugate vaccines reduce myringotomy with tympanostomy tube insertion in young children in Japan

OBJECTIVE

Pneumococcal conjugate vaccines (PCVs) have been reported to reduce the incidence of myringotomy with tympanostomy tube insertion (MTTI) in children. However, little information is available focusing specific ages. We examined the prophylactic efficacy of PCVs on the onset of complex otitis media (ComOM) that requires MTTI.

METHOD

From 2011, the public support for PCV7 started with the usual four-dose schedule and an emergency schedule for 2- to 4-year-old children in Japan. PCV7 was replaced with PCV13 in 2013. We reviewed the nationwide database obtained from the JMDC Claims Database (https://www.jmdc.co.jp/en/) to examine the MTTI incidence during the era before and after PCV introduction (from 2008 to 2010 and from 2011 to 2017, respectively). Subjects were analyzed by stratified age groups (from 0 to 8 years old) and in subdivided groups of 6 months (from 0 to 35 months old). We compared the MTTI incidence between the groups for each age as well as between those for each calendar year.

RESULTS

A significant reduction in the MTTI incidence was detected in the 1-year-old children of the PCV era compared to those of the pre-PCV era. The reduction rates were more prominent in the 12-17 months group as compared to the 18-23 months group (PCV7 p = .005 and PCV13 p = .011, PCV7 p = .014 and PCV13 p = .153, respectively). The significant difference in the 1-year-old children continued in six of seven calendar years from 2011 to 2017, whereas no significant reduction was detected in children >3 years old.

CONCLUSIONS

The introduction of both PCV7 and PCV13 reduced MTTI incidences in children around 1 year old, and the effects were more prominent during the early half-periods. Our results support etiological evidence that pneumococcal infection in children aged 1 year and younger might play roles in the pathogenesis of ComOM that requires MTTI.

Risk factors for childhood pneumonia: a case-control study in a high prevalence area in Indonesia

BACKGROUND

Acute respiratory infections (ARIs), especially pneumonia, remain a major cause of infant mortality worldwide. In Indonesia, pneumonia is the second most common cause of infant and toddler deaths. Exclusive breastfeeding and basic immunization can protect infants and children from contracting pneumonia.

PURPOSE

Our goal was to assess the risk factors for childhood pneumonia in regions with a high prevalence of pneumonia in Indonesia.

METHODS

This case-control study was conducted between March and April 2019. A total of 176 infants and toddlers aged 10-59 months were enrolled and selected from among patients who visited the community health center. Cases of pneumonia were diagnosed clinically based on the World Health Organization guidelines, and the control was nonpneumonia.

RESULTS

The risk factors for the diagnosis of pneumonia included no or nonexclusive breastfeeding (odds ratio [OR], 7.95; 95% confidence interval [CI], 3.52-17.94), incomplete basic immunizations (OR, 4.47; 95% CI, 2.22-8.99), indoor air pollution (OR, 7.12; 95% CI, 3.03-16.70), low birth weight (OR, 3.27; 95% CI, 1.19-8.92), and a high degree of wasting (OR, 2.77; 95% CI, 1.06-7.17). Other variables such as nutritional status (height-for-age z score), age, sex, and educational status of the mother were not risk factors for pneumonia.

CONCLUSION

No or nonexclusive breastfeeding, incomplete basic immunizations, indoor air pollution, a history of low birth weight, and severe malnutrition were risk factors for childhood pneumonia. Breastfeeding was the dominant factor, while sex modified the relationship between exclusive breastfeeding and the incidence of pneumonia.

Vaccination in preterm and low birth weight infants in India

In India, the high neonatal and infant mortality rate is due in part to an increasing number of preterm and low birth weight (LBW) infants. Given the immaturity of immune system, these infants are at an increased risk of hospitalization and mortality from vaccine-preventable diseases (VPDs). In this narrative review, we screened the scientific literature for data on the risk of VPDs, vaccination delay and factors related to it in Indian preterm and LBW infants. Although routine childhood vaccinations are recommended regardless of gestational age or birth weight, vaccination is often delayed. It exposes these infants to a higher risk of infections, their associated complications, and death. After-birth complications, lack of awareness of recommendations, vaccine efficacy and effectiveness and concerns related to safety are some of the common barriers to vaccination. Awareness campaigns might help substantiate the need for (and value of) vaccination in preterm and LBW infants.

What is the context?

In India, the high neonatal mortality rate is due in part to an increasing number of pretern and low birth weight intants.

Affected infants have a poorly developed inmune system and are more susceptible to contracting vaccine-preventable diseases.

The Indian Academy of Pediatrics recommends vaccination according to the same schedule used for full term infants, following chronological (not gestational) age.

Delays in vaccinations increase the risk of preventable infections.

What is new?

Our review of the scientific literature shows that, in India:

infections have more serious conseuences in preterm and low birth weight infants

delays to vaccinate affected infants are common, mostly due to safety and effectiveness concerns from parents and healthcare pracitionrs.

What is the impact?

Improving mternal nutritional status and immunization, and perinatal care could help reduce the number of preterm and low birth weight infants.

Combining maternal immunization with vaccination of affected infants can confer safe and effective protection.

Awareness campaigns for parents and healthcare practitioners could address the issue of vaccination delay in pretern and low birth weight infants in India.

Maternal Immunization: Nature Meets Nurture

Vaccinating women in pregnancy (i.e., maternal immunization) has emerged as a promising tool to tackle infant morbidity and mortality worldwide. This approach nurtures a 'gift of nature,' whereby antibody is transferred from mother to fetus transplacentally during pregnancy, or postnatally in breast milk, thereby providing passive, antigen-specific protection against infections in the first few months of life, a period of increased immune vulnerability for the infant. In this review, we briefly summarize the rationale for maternal immunization programs and the landscape of vaccines currently in use or in the pipeline. We then direct the focus to the underlying biological phenomena, including the main mechanisms by which maternally derived antibody is transferred efficiently to the infant, at the placental interface or in breast milk; important research models and methodological approaches to interrogate these processes, particularly in the context of recent advances in systems vaccinology; the potential biological and clinical impact of high maternal antibody titres on neonatal ontogeny and subsequent infant vaccine responses; and key vaccine- and host-related factors influencing the maternal-infant dyad across different environments. Finally, we outline important gaps in knowledge and suggest future avenues of research on this topic, proposing potential strategies to ensure optimal testing, delivery and implementation of maternal vaccination programs worldwide.