The impact of childhood pneumococcal conjugate vaccine immunisation on all-cause pneumonia admissions in Hong Kong: A 14-year population-based interrupted time series analysis

Burden of Pneumococcal Disease in Young Children Due to Serotypes Contained in Different Pneumococcal Conjugate Vaccines in Eight Asian Countries and Territories

BACKGROUND

Pneumococcal disease (PD) is a major cause of morbidity and mortality in young children in Asia and globally. Pneumococcal conjugate vaccines (PCVs) have significantly reduced the burden of PD when included in pediatric national immunization programs (NIPs). This study estimates the clinical and economic burden of PD due to serotypes contained in different PCVs in children aged < 5 years in eight Asian countries/territories.

METHODS

Based on published data, a cohort-based decision analytic model was used to estimate annual PD cases, deaths, and direct medical costs associated with serotypes contained in PCV10, PCV13, PCV15, and PCV20.

RESULTS

PD incidence rates were lower in regions with PCV13 in their NIP than those without. Serotypes contained in higher but not lower valency PCVs resulted in a significant incremental clinical and economic burden, although the difference between PCV13 and PCV15 serotypes was generally small. Moving from PCV13 to PCV20 was estimated to result in greater clinical and economic burden reductions.

CONCLUSIONS

This study demonstrates the remaining and incremental burden of PD from PCV10 to PCV20 serotypes in young children in selected Asian regions. Extending NIP access to higher-valency PCVs with broader serotype coverage and improving vaccine uptake will help prevent morbidity and deaths and save healthcare costs.

Protective Effects from Prior Pneumococcal Vaccination in Patients with Chronic Airway Diseases during Hospitalization for Influenza-A Territory-Wide Study

Influenza is an important respiratory viral pathogen in adults, with secondary bacterial pneumonia being a common complication. While pneumococcal vaccines can prevent pneumococcal pneumonia and invasive pneumococcal disease, whether they can also prevent the severe in-hospital outcomes among patients hospitalized for influenza has not been examined. A territory-wide retrospective study was conducted in Hong Kong, which included all adult patients having chronic airway diseases (asthma, bronchiectasis, and chronic obstructive pulmonary disease) hospitalized for influenza and who had received seasonal influenza vaccine. The occurrence of secondary bacterial pneumonia, mortality, and other severe in-hospital outcomes were compared among subjects with or without pneumococcal vaccination. There was a total of 3066 eligible patients who were hospitalized for influenza in public hospitals in Hong Kong from 1 January 2016 to 30 June 2023. Completed pneumococcal vaccination with PSV23/PCV13 conferred protection against secondary bacterial pneumonia, all-cause mortality, and respiratory cause of mortality with adjusted odds ratios of 0.74 (95% CI = 0.57-0.95, p = 0.019), 0.12 (95% CI = 0.03-0.53, p = 0.005), and 0.04 (95% CI = 0.00-0.527, p = 0.0038), respectively.

Disease Burden of Meningitis Caused by Streptococcus pneumoniae Among Under-Fives in China: A Systematic Review and Meta-analysis

INTRODUCTION

Streptococcus pneumoniae is the leading cause of meningitis, with a case fatality of up to about 50%. Children younger than 5 years are at greater risk for pneumococcal meningitis compared with other populations. It is of significant importance to provide a comprehensive understanding of the burden of pneumococcal meningitis among under-fives in the low pneumococcal conjugate vaccine (PCV) coverage period in China.

METHODS

A systematic review was conducted. We searched both English (PubMed, Ovid-EMBASE, Biosis, Web of Science, and Cochrane) and Chinese (CNKI, Wanfang, and ViP) databases for studies on bacterial meningitis in China published between January 1980 and July 2022. Ineligible studies were excluded based on study design and data integrity. Heterogeneity was assessed with I2 and estimates of bacterial meningitis morbidity and mortality were pooled using random-effects models. Subgroup analysis was conducted to trace the source of the heterogeneity and summarize average estimates.

RESULTS

A total of 13,082 studies were identified in the literature, and 56 studies were finally included for data analysis. The estimated incidence of pneumococcal meningitis was 2.10 cases per 100,000 children younger than 5 years each year (95% CI: 0.59-7.46), with a pooled case fatality rate of 24.59% (95%CI: 19.35-30.28%) in China. It was estimated that 1617.16 (95% CI: 454.35-5744.78) pneumococcal meningitis cases and 548.86 (95% CI: 474.80-627.62) deaths occurred among under-fives in China in 2020. Streptococcus pneumoniae played an important role in the etiology of confirmed bacterial meningitis cases, with a pooled proportion of 22.05% (95% CI: 17.83-26.27%). The most prevalent serotypes were 6B, 14, 19F, 19A, and 23F, which were preventable with a vaccine.

CONCLUSIONS

Pneumococcal meningitis remains one of the most important health problems among children younger than 5 years in China. Immunization programs should be promoted to avoid preventable cases and deaths.

Incidence of acute otitis media from 2003 to 2019 in children ≤ 17 years in England

BACKGROUND

The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2006 and the 13-valent pneumococcal conjugate vaccine (PCV13) in 2010 in the UK. PCVs are active immunization for the prevention of invasive disease, pneumonia and acute otitis media (AOM) caused by Streptococcus pneumoniae in children. The aim of this observational study was to estimate incidence rates (IRs) of AOM in children ≤17 years from 2003 to 2019 in England, before and after the introduction of pneumococcal conjugate vaccines (PCVs).

METHODS

AOM episodes were identified using Read diagnosis codes in children aged ≤17 years in the Clinical Practice Research Datalink (CPRD) Gold database from 2003 to 2019. Annual IRs with 95% confidence intervals (CI) by age group were calculated as the number of episodes/person-years (PY) at risk. Interrupted time series analyses were conducted to estimate incidence rate ratios (IRR) across post-PCV7 (2007-2009), early post-PCV13 (2011-2014) and late post-PCV13 (2015-2019) periods compared to the pre-PCV7 period (2003-2005) using generalized linear models.

RESULTS

From 2003 to 2019, 274,008 all-cause AOM episodes were identified in 1,500,686 children. The overall AOM IR was 3690.9 (95% CI 3677.1-3704.8) per 100,000 PY. AOM IRs were highest in children aged < 5 years and decreased by age; < 2 years: 8286.7 (95% CI 8216.8-8357.1); 2-4 years: 7951.8 (95% CI 7902.5-8001.4); 5-17 years: 2184.4 (95% CI 2172.1-2196.8) (per 100,000 PY). Overall AOM IRs declined by 40.3% between the pre-PCV7 period and the late-PCV13 period from 4451.9 (95% CI 4418.1-4485.9) to 2658.5 (95% CI 2628.6-2688.7) per 100,000 PY, and across all age groups. IRRs indicated a significant decrease in AOM IRs in all the post-vaccination periods, compared to the pre-PCV7 period: post-PCV7 0.87 (95% CI 0.85-0.89), early post-PCV13 0.88 (95% CI 0.86-0.91), and late post-PCV13 0.75 (95% CI 0.73-0.78).

CONCLUSIONS

The AOM IRs declined during the 2003-2019 period; however, the clinical burden of AOM remains substantial among children ≤17 years in England.

Population-Based Clinical Studies Using Routinely Collected Data in Hong Kong, China: A Systematic Review of Trends and Established Local Practices

Background: Routinely collected health data are increasingly used in clinical research. No study has systematically reviewed the temporal trends in the number of publications and analyzed different aspects of local research practices and their variations in Hong Kong, China, with a specific focus on research ethics governance and approval.

Methods: PubMed was systematically searched from its inception to March 28, 2023, for studies using routinely collected healthcare data from Hong Kong.

Results: A total of 454 studies were included. Between 2000 and 2009, 32 studies were identified. The number of publications increased from 5 to 120 between 2010 and 2022. Of the investigator-led studies using the Hospital Authority (HA)’s cross-cluster data (n = 393), 327 (83.2%) reported receiving ethics approval from a single cluster/university-based REC, whereas 50 studies (12.7%) did not report approval from a REC. For use of the HA Data Collaboration Lab, approval by a single hospital-based or University-based REC is accepted. Repeated submission of identical ethics applications to different RECs is estimated to cost HK$4.2 million yearly.

Conclusions: Most studies reported gaining approval from a single cluster REC before retrieval of cross-cluster HA data. Substantial cost savings would result if repeated review of identical ethics applications were not required.

Hereditary spherocytosis before and after splenectomy and risk of hospitalization for infection

BACKGROUND

The infectious burden in hereditary spherocytosis (HS) children before splenectomy has rarely been reported and the risk of severe postsplenectomy infection is controversial.

METHODS

We conducted a retrospective study of pediatric patients with HS to evaluate the risk of infection presplenectomy and postsplenectomy. The primary outcome was any bacterial, Mycoplasma, or fungal infection that required hospitalization. The secondary outcomes were sepsis and septic shock. Appendectomized children were matched on age at surgery and enrolled as controls.

RESULTS

In all, 232 patients were included. Before splenectomy, the primary outcome was identified in 51 (22.0%) patients, and the secondary outcome was identified in 1 (0.4%) patient. After splenectomy, the primary and secondary outcomes were detected in 8 (4.1%) and 1 (0.5%) patients, respectively. The risk of infection was higher presplenectomy than postsplenectomy (OR, 6.6; 95% CI, 3.0-14.2). HS patients had a higher risk of infection than the controls before surgery (OR, 3.7; 95% CI, 2.3-5.9) but not after surgery (OR, 1.4; 95% CI, 0.6-3.6).

CONCLUSIONS

HS patients who require splenectomy later in life had a high incidence of hospitalization for infections. In contrast, postsplenectomy risk of hospitalization involving infection or severe infection was low.

IMPACT

Patients with hereditary spherocytosis who require splenectomy later in life have a high risk of hospital admission for infections, especially those with severe hereditary spherocytosis. With vaccines or postoperative antibiotics, splenectomy does not increase the risk of infection or severe infections. Splenectomy may reduce the risk of hospitalization for infections by alleviating the complications of hereditary spherocytosis. With vaccines, prophylaxis, or advanced antibiotics, the benefits of splenectomy in children with hereditary spherocytosis and a heavy disease burden may outweigh the risks.