Vaccine effectiveness of the 7-valent and 13-valent pneumococcal conjugate vaccines in Canada: An IMPACT study

The microbiological characteristics and diagnosis of Streptococcus pneumoniae infection in the conjugate vaccine era

Two pneumococcal conjugate vaccines, PCV15 and PCV20, were licensed in June 2021. PCV15 includes two additional serotypes (22F, 33F) beyond those in PCV13, while PCV20 adds seven more (8, 10A, 11A, 12F, 15B, 22F, 33F), covering approximately 30% of invasive pneumococcal disease (IPD) cases in adults. In June 2023, the US CDC's Advisory Committee on Immunization Practices (ACIP) recommended either PCV15 or PCV20 for all children aged < 5 years and children aged 2‒18 years with risk conditions. In June 2024, the FDA approved PCV21 for adults ≥ 18 years. In October 2024, ACIP recommended either PCV20 or PCV21 alone or PCV15 with PPSV23 for adults ≥ 50 years or 19-49 years with risk conditions. These advancements highlight the evolving landscape of pneumococcal vaccination. This review examines the molecular epidemiology of pneumococcal infections, advancements in diagnostic methods, and the anticipated public health impact of these vaccines in reducing pneumococcal disease burden.

Future immunisation strategies to prevent Streptococcus pneumoniae infections in children and adults

Streptococcus pneumoniae is a major respiratory pathogen, causing 1·2 million deaths and 197 million pneumonia episodes globally in 2016. The spread of S pneumoniae to sterile sites, such as the blood and brain, leads to invasive pneumococcal disease. The best approach available for prevention of invasive pneumococcal disease in children and, more recently, adults is the use of pneumococcal conjugate vaccines (PCVs). PCVs are also highly effective at preventing colonisation and, thus, transmission, offering indirect protection to non-target immunisation groups such as adults-a characteristic that has been crucial in their success. However, PCVs only include and protect up to 20 of the 100 serotypes that can cause disease. The rise in adult cases of invasive pneumococcal disease from serotypes included in PCVs suggests indirect protection might be limited. Additionally, non-vaccine serotypes and some vaccine types that persist, some linked to antibiotic resistance, continue to cause disease. Future vaccine strategies include increasing the number of serotypes covered in PCVs for use in children and adults, broader vaccine use in adults, the development of adult-specific conjugate vaccines containing serotypes different from those covered in PCVs used in children, and protein vaccines, all of which will be explored in this Review. These strategies are expected to help mitigate the global burden of invasive pneumococcal disease in future years.

Serotype specific pneumococcal vaccine effectiveness in children with sickle cell disease: A two-decade analysis

OBJECTIVES

Sickle cell disease (SCD) is the most common genetic hematologic disease globally and children with SCD are at increased risk for pneumococcal disease.

METHODS

We utilized data from population-based enhanced surveillance for invasive pneumococcal disease (IPD) in children <18 years of age in Massachusetts from 2002 to 2020. We calculated incidence rates (IR) among children with SCD using bootstrapping resampling and incidence rate ratios (IRR) for pre- and post-PCV13 periods. Vaccine effectiveness (VE) was calculated as 100*(1-IRR), and PCV13 vaccine failure probability was predicted using a random forest model.

RESULTS

Children with SCD had higher IR during both pre-/post-PCV13 periods compared with otherwise healthy children 240.0/100,000 versus 4.6/100,000 in pre-PCV13 period (2002-2009); 172.7/100,000 versus 1.9/100,000 in post-PCV13 period (2011-2020), respectively. After widespread use of PCV7 for a decade, a modest reduction of 28.1 % (95% CI 25.9-37.2%) in the incidence of overall IPD during the post-PCV13 period was observed in children with SCD, whereas a more substantial 59.5% (96% CI 57.8-61.4%) reduction was observed in otherwise healthy children. There was a 60.8% (95% CI 55.2%-NA) reduction in the incidence of VST13 IPD in children with SCD and an 83.0% (95% CI 80.67-85.63%) reduction in children without underlying health condition. Overall, 61.1% of the remaining IPD among children with SCD were due to non-PCV13 serotypes (8, 10A, 15A,15B, 22F, 23B), many of which are included in expanded valency vaccines.

CONCLUSION

Children with SCD continue to have higher rates of IPD compared with otherwise healthy children despite vaccination. Majority of the remaining disease is due to serotypes not included in vaccine formulations that have been used for the last two decades. Our study highlights the potential value of expanded valency vaccines and importance of risk-based vaccination strategies tailored for this vulnerable population.

Pneumolysin-responsive liposomal platform for selective treatment of Streptococcus pneumoniae

The bacterium Streptococcus pneumoniae has become a leading cause of meningitis, sepsis, and bacterial pneumonia worldwide, with increased prevalence of antibiotic-resistant serotypes serving to exacerbate the issue. The main factor responsible for colonization and immune response escape in pneumococcal infections is the secreted molecule pneumolysin, which is a subset within a family of related toxins that form transmembrane pores in biological membranes through cholesterol recognition and binding. The conserved activity and structure of pneumolysin between all observed S. pneumoniae serotypes, along with its requirement for pathogenicity, has made this molecule an attractive target for vaccination, diagnostic, and sequestration platforms, but not yet as a facilitative agent for therapeutic treatment. Consequently, the present work aimed to examine the impact of liposomal cholesterol content for pneumolysin-induced release of the encapsulated antimicrobial peptide nisin. It was determined that a cholesterol content above 45 mol% was necessary to facilitate interactions with both purified pneumolysin toxin and S. pneumoniae culture, demonstrated through enhanced nisin release and a reduction in hemolytic rates upon exposure of the toxin with cholesterol-rich vesicles. Antibacterial testing highlighted the ability of the developed platform to elicit a potent and specific bactericidal response in vitro against cultured S. pneumoniae when compared to a control strain, Staphylococcus epidermidis. It further improved viability of a fibroblast cell line upon S. pneumoniae challenge, outperforming free nisin via the synergistic impact of simultaneous bacterial clearance and pneumolysin neutralization. These findings collectively indicate that cholesterol-rich liposomes hold promise as a selective treatment platform against pneumococcal infections.

Pneumococcal serotype prevalence and antibiotic resistance in children in South and Southeast Asia, 2012-2024

This narrative review describes pneumococcal serotype prevalence for invasive disease and carriage and antibiotic resistance among specimens collected from children in countries across South and Southeast Asia from 2012 to 2024. Literature search retrieved 326 articles; 96 were included. The prevalence of pneumococcal serotypes varied geographically and over time after introduction of pneumococcal conjugate vaccine. Serotypes common in both pneumococcal carriage and disease were 6A, 6B, 14, 15B/15C, 19F, and 23F; serotypes 1, 3, 5, 19A, 15A, 10A, and 35B were also common in disease. Most of these serotypes are included in the 13-valent and 10-valent PCV. Carriage and disease isolates remained generally highly susceptible to vancomycin (mostly 100%) and levofloxacin (mostly >97%). These findings indicate that vaccine-preventable serotypes contribute significantly to pneumococcal disease burden in children in South and Southeast Asia. Consistency of national immunization programs with World Health Organization recommendations may reduce rates of pneumococcal disease in this region.

Effectiveness of the ten- and thirteen-valent pneumococcal conjugate vaccines to prevent serotype 19A invasive pneumococcal disease in Quebec, Canada. A Canadian immunization research network (CIRN) study

In the province of Quebec, Canada, a 2 + 1 dose pneumococcal conjugate vaccine (PCV) program for children was implemented in 2004. PCV7, PCV10, PCV13 and a mixed PCV10/PCV13 schedule were sequentially used without catch-up. The effectiveness of vaccination schedules to prevent serotype 19A invasive pneumococcal disease (IPD) in <5-year-old children was estimated by the indirect cohort method during 2009-2023. A total of 248 19A IPD cases and 457 IPD controls were included in the analysis. Adjusted vaccine effectiveness (VEa) for ≥1 dose was 57 % [95 %CI: -1 %,82 %] for PCV10 and 62 % [16 %,83 %] for PCV13. VEa for 3 doses was 69 % [17 %,88 %] for PCV10, 76 % [39 %,90 %] for PCV13 and 86 % [64 %,95 %] for the 2PCV10 + 1PCV13 schedule. Protection provided by the PCV10-only schedule tended to be of lower magnitude compared to the two other schedules. The mixed PCV10 + PCV13 schedule showed a protection against 19A IPD at least comparable to that of 3 PCV-13 doses.

Clinical features and immune memory of breakthrough infection in children after age-appropriate 13-valent pneumococcal conjugate vaccination in Taiwan

PURPOSE

As certain vaccine serotypes are still circulating within the community during the PCV13 era, we aimed to delineate the clinical features and assess the immunity following breakthrough infections in children.

METHODS

101 PCVs-vaccinated children < 18 years with culture confirmed PCV13 serotype breakthrough infection (25/101, invasive pneumococcal disease [IPD]) was identified in Taiwan in 2015-2019. Immunoglobulin G (IgG) antibody levels, IgM+ memory B cells (MBCs), and isotype-switched immunoglobulin (sIg+) MBC specific to serotypes 3, 14, 19 A were assessed prior to and one month after an additional PCV13 booster in 9 patients. A cohort of 89 previously vaccinated, healthy children were enrolled as controls.

RESULTS

The majority (88%) of the breakthrough infection occurred in children under 7 years old. Infection by serotypes 3 and 19 A increased in children aged 5-17 years in 2018-2019. The pre-booster serotype 3- and 19 A-specific IgG in both children with breakthrough infection and controls were lower than the IPD protective thresholds (2.83 µg/mL for 3; 1.00 µg/mL for 19 A). Breakthrough infected children showed higher geometric mean ratio in serotype-specific IgG, IgM+ MBCs and sIg+ MBC after an additional PCV13 booster, compared to the controls.

CONCLUSIONS

Most breakthrough infections occurred in previously healthy preschool-aged children, but such infections may still occur in school-aged children due to waning immunity. Breakthrough infections may also enhance the anamnestic response elicited by PCV13.

Anticipated Effects of Higher-valency Pneumococcal Conjugate Vaccines on Colonization and Acute Otitis Media

BACKGROUND

Bacterial etiologies of acute otitis media (AOM) have shifted from the introduction of pneumococcal conjugate vaccines (PCVs), antibiotic selection and competition among species. We characterized Streptococcus pneumoniae ( Spn ), Haemophilus influenzae ( Hflu ) and Moraxella catarrhalis ( Mcat ) in the nasopharynx during well-child healthy visits and at the onset of AOM, and in middle ear fluid (MEF) of children with AOM to assess anticipated effects of higher-valency PCVs (PCV15 and PCV20).

METHODS

From September 2021 to September 2023, we conducted a prospective longitudinal cohort study of PCV13 immunized children 6-36 months old. MEF was collected via tympanocentesis. Serotyping and antibiotic susceptibility testing were performed on Spn , Hflu and Mcat isolates.

RESULTS

We obtained 825 nasopharyngeal and 216 MEF samples from 301 children. The order of frequency of nasopharyngeal colonization was Mcat , Spn and Hflu ; Hflu was the predominant otopathogen in MEF. Among Spn isolates, non-PCV15, non-PCV20 serotypes predominated in the nasopharynx and in MEF; the most frequent serotype was 35B. Among MEF samples, 30% of Spn isolates were amoxicillin nonsusceptible; 23% of Hflu isolates and 100% of Mcat isolates were β-lactamase-producing.

CONCLUSION

The majority of Spn isolates among young children were non-PCV15, non-PCV20 serotypes, especially serotype 35B; therefore, the impact of higher-valency PCVs in reducing pneumococcal colonization or AOM is expected to be limited. Hflu continues to be the most frequent AOM pathogen. Antibiotic susceptibility data suggest a high dose of amoxicillin/clavulanate or alternative drugs that are effective against contemporary mix of otopathogens could be considered for optimal empiric selection to provide the best efficacy.

Effectiveness of 13-valent pneumococcal conjugate vaccine for prevention of invasive pneumococcal disease among children in the United States between 2010 and 2019: An indirect cohort study

BACKGROUND

A U.S. case-control study (2010-2014) demonstrated vaccine effectiveness (VE) for ≥ 1 dose of the thirteen-valent pneumococcal conjugate vaccine (PCV13) against vaccine-type (VT) invasive pneumococcal disease (IPD) at 86 %; however, it lacked statistical power to examine VE by number of doses and against individual serotypes.

METHODS

We used the indirect cohort method to estimate PCV13 VE against VT-IPD among children aged < 5 years in the United States from May 1, 2010 through December 31, 2019 using cases from CDC's Active Bacterial Core surveillance, including cases enrolled in a matched case-control study (2010-2014). Cases and controls were defined as individuals with VT-IPD and non-PCV13-type-IPD (NVT-IPD), respectively. We estimated absolute VE using the adjusted odds ratio of prior PCV13 receipt (1-aOR x 100 %).

RESULTS

Among 1,161 IPD cases, 223 (19.2 %) were VT cases and 938 (80.8 %) were NVT controls. Of those, 108 cases (48.4 %; 108/223) and 600 controls (64.0 %; 600/938) had received > 3 PCV13 doses; 23 cases (17.6 %) and 15 controls (2.4 %) had received no PCV doses. VE ≥ 3 PCV13 doses against VT-IPD was 90.2 % (95 % Confidence Interval75.4-96.1 %), respectively. Among the most commonly circulating VT-IPD serotypes, VE of ≥ 3 PCV13 doses was 86.8 % (73.7-93.3 %), 50.2 % (28.4-80.5 %), and 93.8 % (69.8-98.8 %) against serotypes 19A, 3, and 19F, respectively.

CONCLUSIONS

At least three doses of PCV13 continue to be effective in preventing VT-IPD among children aged < 5 years in the US. PCV13 was protective against serotypes 19A and 19F IPD; protection against serotype 3 IPD did not reach statistical significance.

Immunogenicity and safety of a 14-valent pneumococcal polysaccharide conjugate vaccine (PNEUBEVAX 14™) administered to 6-8 weeks old healthy Indian Infants: A single blind, randomized, active-controlled, Phase-III study

BACKGROUND

Introduction of pneumococcal conjugate vaccines (PCVs) reduced the number of cases of pneumococcal disease (PD). However, there is an increase in clinical and economic burden of PD from serotypes that are not part of the existing pneumococcal vaccines, particularly impacting pediatric and elder population. In addition, the regions where the PCV is not available, the disease burden remains high. In this study, immunogenicity and safety of the BE's 14-valent PCV (PNEUBEVAX 14™; BE-PCV-14) containing two additional epidemiologically important serotypes (22F and 33F) was evaluated in infants in comparison to licensed vaccine, Prevenar-13 (PCV-13).

METHODS

This is a pivotal phase-3 single blind randomized active-controlled study conducted at 12 sites across India in 6-8 weeks old healthy infants at 6-10-14 weeks dosing schedule to assess immunogenic non-inferiority and safety of a candidate BE-PCV-14. In total, 1290 infants were equally randomized to receive either BE-PCV-14 or PCV-13. Solicited local reactions and systemic events, adverse events (AEs), serious AEs (SAEs), and medically attended AEs (MAAEs) were recorded. Immunogenicity was assessed by measuring anti-PnCPS (anti-pneumococcal capsular polysaccharide) IgG concentration and functional antibody titers through opsonophagocytic activity (OPA), one month after completing three dose schedule. Cross protection to serotype 6A offered by serotype 6B was also assessed in this study.

FINDINGS

The safety profile of BE-PCV-14 was comparable to PCV-13 vaccine. Majority of reported AEs were mild in nature. No severe or serious AEs were reported in both the treatment groups. For the twelve common serotypes and for the additional serotypes (22F and 33F) in BE-PCV-14, NI criteria was demonstrated as defined by WHO TRS-977. Primary immunogenicity endpoint was met in terms of IgG immune responses for all 14 serotypesof BE-PCV-14. Moreover, a significant proportion of subjects (69%) seroconverted against serotype 6A, even though this antigen was not present in BE-PCV-14. This indicates that serotype 6B of BE-PCV-14 cross protects serotype 6A. BE-PCV-14 also elicited comparable serotype specific functional OPA immune responses to all the serotypes common to PCV-13.

INTERPRETATIONS

BE-PCV-14 was found to be safe and induced robust and functional serotype specific immune responses to all 14 serotypes. It also elicited cross protective immune response against serotype 6B.These findings suggest that BE-PCV-14 can be safely administered to infants and achieve protection against pneumococcal disease caused by serotypes covered in the vaccine. The study was prospectively registered with clinical trial registry of India - CTRI/2020/02/023129.

Immunogenicity of Current and Next-Generation Pneumococcal Conjugate Vaccines in Children: Current Challenges and Upcoming Opportunities

Global use of pneumococcal conjugate vaccines (PCVs) with increasingly broader serotype coverage has helped to reduce the burden of pneumococcal disease in children and adults. In clinical studies comparing PCVs, higher-valency PCVs have met noninferiority criteria (based on immunoglobulin G geometric mean concentrations and response rates) for most shared serotypes. A numeric trend of declining immunogenicity against shared serotypes with higher-valency PCVs has also been observed; however, the clinical relevance is uncertain, warranting additional research to evaluate the effectiveness of new vaccines. Novel conjugation processes, carriers, adjuvants, and vaccine platforms are approaches that could help maintain or improve immunogenicity and subsequent vaccine effectiveness while achieving broader protection with increasing valency in pneumococcal vaccines.

Pneumococcal Vaccine Breakthrough and Failure in Infants and Children: A Narrative Review

Globally, Streptococcus pneumoniae is a leading cause of vaccine-preventable morbidity and mortality in infants and children. In recent decades, large-scale pediatric immunization programs have substantially reduced the incidence of invasive pneumococcal disease. Despite this, residual vaccine-type pneumococcal disease remains in the form of vaccine breakthrough and vaccine failure. This targeted literature review aims to discuss aspects of vaccine breakthrough and failure in infants and children, including disease epidemiology, clinical presentation, risk factors, vaccination schedules, vaccine serotypes, correlates of protection, comorbidities, disease surveillance, and potential implications for future vaccine development.

Excess mortality among people with communicable diseases over a 30-year period, Victoria, Australia: a whole of population cohort study

Background

Understanding mortality burden associated with communicable diseases is key to informing resource allocation, disease prevention and control efforts, and evaluating public health interventions. We quantified excess mortality among people notified with communicable diseases in Victoria, Australia.

Methods

Cases of communicable disease notified in Victoria between 1 January 1991 and 31 December 2021 were linked to the death registry. Informational gain obtained through linkage and 30-day case fatality rates were calculated for each disease. Standardised mortality ratios (SMR) and 95% confidence intervals were calculated up to a year following illness onset.

Findings

There were 1,032,619 cases and 5985 (0.58%) died ≤30 days of illness onset. Following linkage, the 30-day case fatality rate increased more than 2-fold. Diseases with high 7-day SMR signifying excess mortality included invasive pneumococcal disease (167.7, 95% CI 153.4-182.7); listeriosis (166.2, 95% CI 121.2-218.3); invasive meningococcal disease (145.9, 95% CI 116.7-178.3); legionellosis (43.3, 95% CI 28.0-62.0); and COVID-19 (21.9, 95% CI 19.7-24.3). Most diseases exhibited a strong negative gradient, with high SMRs in the first 7-days of illness onset that reduced over time.

Interpretation

We demonstrated that the rate of death in Victoria's notifiable disease surveillance dataset is underestimated. Further, compared to a general population, there is evidence of elevated all-cause mortality among people notified with communicable diseases often up to one year following illness onset. Not all elevated risk is likely directly attributable to the communicable diseases of interest, rather, it may reflect underlying comorbidities or behaviours in these individuals. Regardless of attribution, infection with communicable diseases may represent a marker of mortality. Key to preventing deaths may be through timely and appropriate transition to primary and preventive healthcare following diagnosis.

Funding

No funding was provided for this study.

Pan-Genome-Wide Association Study of Serotype 19A Pneumococci Identifies Disease-Associated Genes

Despite the widespread implementation of pneumococcal vaccines, hypervirulent Streptococcus pneumoniae serotype 19A is endemic worldwide. It is still unclear whether specific genetic elements contribute to complex pathogenicity of serotype 19A isolates. We performed a large-scale pan-genome-wide association study (pan-GWAS) of 1,292 serotype 19A isolates sampled from patients with invasive disease and asymptomatic carriers. To address the underlying disease-associated genotypes, a comprehensive analysis using three methods (Scoary, a linear mixed model, and random forest) was performed to compare disease and carriage isolates to identify genes consistently associated with disease phenotype. By using three pan-GWAS methods, we found consensus on statistically significant associations between genotypes and disease phenotypes (disease or carriage), with a subset of 30 consistently significant disease-associated genes. The results of functional annotation revealed that these disease-associated genes had diverse predicted functions, including those that participated in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. Our findings suggest the multifactorial pathogenicity nature of this hypervirulent serotype and provide important evidence for the design of novel protein-based vaccines to prevent and control pneumococcal disease. IMPORTANCE It is important to understand the genetic and pathogenic characteristics of S. pneumoniae serotype 19A, which may provide important information for the prevention and treatment of pneumococcal disease. This global large-sample pan-GWAS study has identified a subset of 30 consistently significant disease-associated genes that are involved in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. These findings suggest the multifactorial pathogenicity nature of hypervirulent S. pneumoniae serotype 19A isolates and provide implications for the design of novel protein-based vaccines.

Antimicrobial susceptibility testing of invasive isolates of Streptococcus pneumoniae from Canadian patients: the SAVE study, 2011-2020

OBJECTIVES

To assess the antimicrobial susceptibility of 14 138 invasive Streptococcus pneumoniae isolates collected in Canada from 2011 to 2020.

METHODS

Antimicrobial susceptibility testing was performed using the CLSI M07 broth microdilution reference method. MICs were interpreted using 2022 CLSI M100 breakpoints.

RESULTS

In 2020, 90.1% and 98.6% of invasive pneumococci were penicillin-susceptible when MICs were interpreted using CLSI meningitis or oral and non-meningitis breakpoints, respectively; 96.9% (meningitis breakpoint) and 99.5% (non-meningitis breakpoint) of isolates were ceftriaxone-susceptible, and 99.9% were levofloxacin-susceptible. Numerically small, non-temporal, but statistically significant differences (P < 0.05) in the annual percentage of isolates susceptible to four of the 13 agents tested was observed across the 10-year study: chloramphenicol (4.4% difference), trimethoprim-sulfamethoxazole (3.9%), penicillin (non-meningitis breakpoint, 2.7%) and ceftriaxone (meningitis breakpoint, 2.7%; non-meningitis breakpoint, 1.2%). During the same period, annual differences in percent susceptible values for penicillin (meningitis and oral breakpoints) and all other agents did not achieve statistical significance. The percentage of isolates with an MDR phenotype (resistance to ≥3 antimicrobial classes) in 2011 and 2020 (8.5% and 9.4%) was not significantly different (P = 0.109), although there was a significant interim decrease observed between 2011 and 2015 (P < 0.001) followed by a significant increase between 2016 and 2020 (P < 0.001). Statistically significant associations were observed between resistance rates to most antimicrobial agents included in the MDR analysis (penicillin, clarithromycin, clindamycin, doxycycline, trimethoprim/sulfamethoxazole and chloramphenicol) and patient age, specimen source, geographic location in Canada or concurrent resistance to penicillin or clarithromycin, but not biological sex of patients. Given the large isolate collection studied, statistical significance did not necessarily imply clinical or public health significance in some analyses.

CONCLUSIONS

Invasive pneumococcal isolates collected in Canada from 2011 to 2020 generally exhibited consistent in vitro susceptibility to commonly tested antimicrobial agents.

The impact of vaccination on the burden of invasive pneumococcal disease from a nationwide surveillance program in Lebanon: an unexpected increase in mortality driven by non-vaccine serotypes

BACKGROUND

The impact of pneumococcal conjugate vaccines (PCVs) on the burden of invasive pneumococcal disease (IPD) and serotype distribution was examined across age groups from data collected by the Lebanese Inter-Hospital Pneumococcal Surveillance Program.

METHODS

Between 2005 and 2020, 593 invasive Streptococcus pneumoniae isolates were collected from 79 hospitals throughout Lebanon. Serotypes and antimicrobial resistance (AMR) profiles were identified, and trends compared over 3 eras: PCV7, post-PCV7/ pre-PCV13, and PCV13 eras.

RESULTS

The prevalence of PCV7 serotypes decreased significantly from 43.6% in the PCV7 era to 17.8% during the PCV13 era (p<0.001). PCV13-only serotypes remained stable in the PCV13 compared to the post-PCV7 eras, especially serotypes 1 and 3, whereas non-vaccine types (NVT) increased throughout the study period, especially 24 and 16F. The mortality rate increased substantially from 12.5% (PCV7 era) to 24.8% (PCV13 era). A significant decrease in AMR was observed across the three study eras.

CONCLUSION

PCVs substantially impacted IPD and AMR in vaccinated and unvaccinated populations despite an increase in mortality driven by NVT. Broadening the recommendation of vaccination to include older age-groups, using higher valency vaccines, and implementing stringent antimicrobial stewardship are likely to further impact the burden of IPD.