Effect of vaccination on the use of antimicrobial agents: a systematic literature review

From Protection to Prevention: Redefining Vaccines in the Context of Antimicrobial Resistance

Antimicrobial resistance (AMR) poses a significant threat to global health, compromising the effectiveness of treatments and increasing medical risks. In this crisis, the importance of vaccines in reducing AMR is being increasingly acknowledged, although not thoroughly explored. This literature review asserts that vaccines can significantly lessen the occurrence of infections, thereby reducing the need for antibiotics and limiting the emergence of resistance. Vaccines play a crucial role in antimicrobial stewardship programs by preventing diseases that would otherwise necessitate the use of antibiotics. Expanding vaccine coverage supports responsible usage of antimicrobials and aligns with global health priorities to maintain effective medical interventions. This review emphasizes the need for equitable funding and policy support for vaccine initiatives comparable to new antibiotics and diagnostic techniques. Moreover, it calls for more detailed investigations into vaccines' economic and health benefits in managing AMR, highlighting their potential as cost-effective solutions to this urgent health challenge. Through a careful analysis of existing literature, this review highlights the fundamental role of vaccines in transforming the landscape of AMR, shifting the focus from a protective approach to a preventive health strategy.

Specific and Nonspecific Effects of Influenza Vaccines

With the introduction of the influenza vaccine in the official immunization schedule of most countries, several data regarding the efficacy, tolerability, and safety of influenza immunization were collected worldwide. Interestingly, together with the confirmation that influenza vaccines are effective in reducing the incidence of influenza virus infection and the incidence and severity of influenza disease, epidemiological data have indicated that influenza immunization could be useful for controlling antimicrobial resistance (AMR) development. Knowledge of the reliability of these findings seems essential for precise quantification of the clinical relevance of influenza immunization. If definitively confirmed, these findings can have a relevant impact on influenza vaccine development and use. Moreover, they can be used to convince even the most recalcitrant health authorities of the need to extend influenza immunization to the entire population. In this narrative review, present knowledge regarding these particular aspects of influenza immunization is discussed. Literature analysis showed that the specific effects of influenza immunization are great enough per se to recommend systematic annual immunization of younger children, old people, and all individuals with severe chronic underlying diseases. Moreover, influenza immunization can significantly contribute to limiting the emergence of antimicrobial resistance. The problem of the possible nonspecific effects of influenza vaccines remains unsolved. The definition of their role as inducers of trained immunity seems essential not only to evaluate how much they play a role in the prevention of infectious diseases but also to evaluate whether they can be used to prevent and treat clinical conditions in which chronic inflammation and autoimmunity play a fundamental pathogenetic role.

Assessing the utilization of antimicrobial agents in pediatric pneumonia during the era of the 13-valent pneumococcal conjugate vaccine: A retrospective, single-center study

BACKGROUND AND PURPOSE

Pneumonia and bronchopneumonia are the most common infectious diseases in children. This study aimed to analyze changes in causative pathogens and antibiotic use for bronchopneumonia or pneumonia after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in children.

METHODS

This retrospective study was conducted from 2009 to 2019. Hospitalized children aged 6 months-3 years with a discharge diagnosis of bronchopneumonia or pneumonia were included to analyze changes in the potential mismatch between the diagnosed pathogen and antibiotic use.

RESULTS

The cohort comprised 1100 patients, including 648 (59%) and 452 (41%) with a discharge diagnosis of bronchopneumonia and pneumonia, respectively. The trend of viral pneumonia increased every year (rs = 0.101, p < 0.05) Antibiotics were administered in 97% patients, with an increasing annual trend in macrolide use (rs = 0.031, p = 0.009). Regarding antibiotic utilization, no significant variations were observed in the days of therapy (DOT) (rs = 0.076, p = 0.208) or length of therapy (LOT) (rs = -0.027, p = 0.534) per patient-year throughout the study duration. Interestingly, the LOT for combined therapy with macrolides and first-line beta-lactams was high (rs = 0.333, p = 0.028). In viral pneumonia treatment, neither the DOT nor LOT exhibited significant variations (rs = -0.006, p = 0.787 and rs = -0.156, p = 0.398).

CONCLUSION

After the introduction of PCV13 in Taiwan, no decrease in antibiotic use has been observed among children aged 6 months-3 years with a discharge diagnosis of bronchopneumonia and pneumonia.

The Role of Adult Vaccines as Part of Antimicrobial Stewardship: A Scoping Review

BACKGROUND

Antimicrobial resistance (AMR) is a significant global health concern, causing an estimated 700,000 deaths annually. Although immunisation has been shown to significantly reduce AMR, the role of vaccines as part of antimicrobial stewardship (AMS) practices is often overlooked.

OBJECTIVE

To identify and examine the available literature on the role of vaccines as part of AMS practices.

METHOD

A scoping review was conducted in the following databases: MEDLINE, Embase, Scopus, CINAHL, CCRCT, IPA, and WoS, along with grey literature sources. The review was conducted using the JBI Methodology for Scoping Reviews and reported in line with the PRISMA-SCr checklist.

RESULTS

Among the 1711 records identified, 34 met the inclusion criteria; 8 discussed only the concept, while 26 discussed both the concept and the vaccine implementation method in AMS practices. There were eight recommended and/or utilised types of AMS activities identified involving vaccines, under four key themes of vaccine-related AMS strategies: Education, Screening, Vaccination, and Monitoring. Influenza and pneumococcal vaccines had the most evidence for inclusion.

CONCLUSION

Overall, the evidence supports the role of vaccines as part of AMS practices and the value of their inclusion in creating improved and comprehensive AMS strategies to further combat the development of AMR.

Challenges in development of vaccines directed toward antimicrobial resistant bacterial species

Antimicrobial resistance (AMR) is considered by WHO one of the top ten public health threats. New control strategies involving concerted actions of both public and private sectors need to be developed. Vaccines play a major role in controlling the spread of AMR pathogens by decreasing transmission and limiting the use of antibiotics, reducing at the end the selective pressure for the emergence of new resistant strains. In this review, by using as example some of the most serious AMR pathogens, we highlighted the major hurdles from a research and development point of view. New approaches to better understand the immunological mechanisms of response to both natural infections and vaccines that aimed to identify correlates of protection, together with the application of new technologies for vaccine design and delivery are discussed as potential solutions.

The impact of influenza and pneumococcal vaccination on antibiotic use: an updated systematic review and meta-analysis

BACKGROUND

Vaccination can prevent bacterial and viral infections that could otherwise increase the chances of receiving (unnecessary) antibiotic treatment(s). As a result, vaccination may provide an important public health intervention to control antimicrobial resistance (AMR).

OBJECTIVES

Perform a systematic literature review to better understand the impact of influenza, pneumococcal and COVID-19 vaccination on antibiotic use, and to identify differences in effect between world regions and study designs.

METHODS

We performed a systematic literature review and meta-analysis which updated previous literature reviews with new data from 1 October 2018 to 1 December 2021. The study focuses on randomised controlled trials (RCTs) and observational studies. Results from the meta-analysis of RCTs were stratified by WHO region and age group. Vote counting based on the direction of effect was applied to synthesize the results of the observational studies.

RESULTS

Most studies are performed in the WHO European Region and the Region of the Americas in high-income countries. RCTs show that the effect of influenza vaccination on the number of antibiotic prescriptions or days of antibiotic use (Ratio of Means (RoM) 0.71, 95% CI 0.62-0.83) is stronger compared to the effect of pneumococcal vaccination (RoM 0.92, 95% CI 0.85-1.00). These studies also confirm a reduction in the proportion of people receiving antibiotics after influenza vaccination (Risk Ratio (RR) 0.63, 95% CI 0.51-0.79). The effect of influenza vaccination in the European and American regions ranged from RoM 0.63 and 0.87 to RR 0.70 and 0.66, respectively. The evidence from observational studies supports these findings but presents a less consistent picture. No COVID-19 studies were identified.

CONCLUSION

We find that both RCTs and observational studies show that influenza vaccination significantly reduces antibiotic use, while the effect of pneumococcal vaccination is less pronounced. We were unable to study the effect of COVID-19 vaccination and no clear regional patterns were found due to the high heterogeneity between studies. Overall, our data supports the use of influenza vaccination as an important public health intervention to reduce antibiotic use and possibly control AMR.

The Effects of Health Education on the Awareness of Antimicrobial Resistance Among High School Students in Riyadh, Saudi Arabia During 2023: A Quasi-experimental Study

Introduction Antimicrobial resistance (AMR) is a major health threat, recently declared a crisis by the WHO, and recognized as one of the top 10 threats to global health. One of the strategies to curb AMR is interventional education to raise awareness. Therefore, this study evaluated the impact of interventional education on awareness of antimicrobial resistance among high school students in Riyadh, Saudi Arabia. Methods This was a quasi-experimental study that included 120 high school students as a control group and 120 students as the experimental group. It used a questionnaire pre- and post-educational intervention, which was a lecture by trained healthcare workers. Pearson's Chi-square test and ANOVA were used to assess the effects of the intervention, and the p-value was set at <0.05 for significance. Results Over half (53.4%) of the controls reported no prior exposure to an antibiotic awareness campaign, compared to 46.6% in the intervention (experimental) group. Half of the participants in both groups were without a family relative who works in the healthcare sector. Almost half (51.2%) in the intervention group used antibiotics compared to 48.2% of controls; 53.3% in the control group reported self-medication compared to 46.7% in the intervention group. We found a statistically significant increase in the overall mean scores regarding knowledge of antibiotics resistance before and after the education intervention in the control group (p<0.001) and intervention group (p<0.001). Post-intervention, there was a significant reduction in the mean scores of misbeliefs about antibiotic use (p<0.001). We found an improvement in the perception scores toward AMR and antibiotic resistance post-educational intervention (P=0.008), and the perception difference remained significant between the two study groups (p=0.002). Conclusion These findings showed that interventional education effectively raises awareness, knowledge, and perceptions toward AMR. Therefore, public health, medical, and scientific professionals in Saudi Arabia are urged to emphasize education to fight AMR, in addition to other strategies.

Global and regional burden of attributable and associated bacterial antimicrobial resistance avertable by vaccination: modelling study

INTRODUCTION

Antimicrobial resistance (AMR) is a global health threat with 1.27 million and 4.95 million deaths attributable to and associated with bacterial AMR, respectively, in 2019. Our aim is to estimate the vaccine avertable bacterial AMR burden based on existing and future vaccines at the regional and global levels by pathogen and infectious syndromes.

METHODS

We developed a static proportional impact model to estimate the vaccination impact on 15 bacterial pathogens in terms of reduction in age-specific AMR burden estimates for 2019 from the Global Research on Antimicrobial Resistance project in direct proportion to efficacy, coverage, target population for protection, and duration of protection of existing and future vaccines.

RESULTS

The AMR burden avertable by vaccination in 2019 was highest for the WHO Africa and South-East Asia regions, for lower respiratory infections, tuberculosis, and bloodstream infections by infectious syndromes, and for Mycobacterium tuberculosis and Streptococcus pneumoniae by pathogen. In the baseline scenario for vaccination of primary age groups against 15 pathogens, we estimated vaccine-avertable AMR burden of 0.51 (95% UI 0.49-0.54) million deaths and 28 (27-29) million disability-adjusted life-years (DALYs) associated with bacterial AMR, and 0.15 (0.14-0.17) million deaths and 7.6 (7.1-8.0) million DALYs attributable to AMR globally in 2019. In the high-potential scenario for vaccination of additional age groups against seven pathogens, we estimated vaccine-avertable AMR burden of an additional 1.2 (1.18-1.23) million deaths and 37 (36-39) million DALYs associated with AMR, and 0.33 (0.32-0.34) million deaths and 10 (9.8-11) million DALYs attributable to AMR globally in 2019.

CONCLUSION

Increased coverage of existing vaccines and development of new vaccines are effective means to reduce AMR, and this evidence should inform the full value of vaccine assessments.

Available evidence and potential for vaccines for reduction in antibiotic prescriptions

Bacterial antibiotic resistance is a public health issue. It means that drugs become ineffective, infections persist and have a huge impact on the health of patients and their spreading increases. To address a complex threat such as bacterial antibiotic resistance different and integrated approaches are needed including discovery of new antibiotics, improvement of diagnostics tools and improvement of antibiotic stewardship. Absolutely relevant are prevention of infections as well as decrease in the use of antibiotics. Vaccines are an important tool in the fight against bacterial antibiotic resistance and can help prevent it in several ways. Indeed, vaccines are highly effective in preventing diseases that might otherwise require the use of antibiotics to treat symptoms and associated complications. Preventing infections through vaccination helps reduce the need for and widespread and inappropriate use of antibiotics, including for secondary bacterial infections.

Assessment of the inclusion of vaccination as an intervention to reduce antimicrobial resistance in AMR national action plans: a global review

BACKGROUND

Vaccination can reduce antibiotic use by decreasing bacterial and viral infections and vaccines are highlighted in the WHO Global Action Plan on Antimicrobial Resistance (AMR) as an infection prevention measure to reduce AMR. Our study aimed to analyze whether WHO Member States have developed AMR national action plans that are aligned with the Global Action Plan regarding objectives on vaccination.

METHODS

We reviewed 77 out of 90 AMR national action plans available in the WHO library that were written after publication of the Global Action Plan in 2015. Each plan was analyzed using content analysis, with a focus on vaccination and key components as defined by WHO (I. Strategic plan (e.g. goals and objectives), II. Operational plan, III. Monitoring and Evaluation plan).

RESULTS

Vaccination was included in 67 of 77 AMR plans (87%) across all WHO Regions (Africa: n = 13/13, the Eastern Mediterranean: n = 15/16, Europe: n = 10/14, the Americas: n = 8/8, South-East Asia: n = 8/11, and the Western Pacific: n = 13/15). Pneumococcal and influenza vaccination were most frequently highlighted (n = 12 and n = 11). We found indications that vaccination objectives are more often included in AMR plans from higher income countries, while lower income countries more often include specific vaccines. The key WHO components of national action plans were frequently not covered (I. 47% included, II. 57%, III. 40%). In total, 33 countries (43%) included indicators (e.g. strategic objectives) to capture the role of vaccines against AMR.

CONCLUSIONS

While vaccination to reduce AMR is seen as an important global public health issue by WHO, there appears to be a gap in its adoption in national AMR plans. Country income levels seem to influence the progress, implementation and focus of national action plans, guided by a lack of funding and prioritization in developing countries. To better align the global response to AMR, our review suggests there is a need to update national action plans to include objectives on vaccination with more focus on specific vaccines that impact antibiotic use.

Predicting COVID-19 vaccine hesitancy in Hong Kong: Vaccine knowledge, risks from coronavirus, and risks and benefits of vaccination

Introduction

Hongkongers have had access to COVID-19 vaccines for about four months, but vaccination rate remains low (34.4% as of 4 July 2021). Given that vaccine uptake is vital, this study aimed to determine how vaccine-hesitant and vaccinated individuals differ. The study also examined why people choose to delay vaccination (within 1 month, within 2 months, within 3 months, 3 months or more).

Material and Methods

A population-based online survey (N = 1654) was conducted between 22 and 30 June 2021, a month after the Hong Kong government announced “Say no to vaccine hesitancy” on its website. All adults aged 18 years and older were eligible to take part. The survey included sociodemographic details, perceived susceptibility to infection, and perceived vaccine efficacy and risks. A series of analyses of covariance was performed to inspect differences among the groups and multiple regression analyses were done to examine factors associated with COVID-19 vaccine hesitancy.

Results

With a vaccine hesitancy rate of 30.3%, analyses revealed that sociodemographic factors, party identification and self-reported health status had no effects on the degrees of vaccine hesitancy. While vaccine knowledge, perceived susceptibility to infection, and vaccine efficacy and safety were positive correlates of vaccine uptake, risks from vaccination and vaccine efficacy were positive correlates of vaccine hesitancy.

Conclusions

Hesitancy in Hong Kong is more about vaccine efficacy and safety, and less about infection risks. Specifically, respondents expressed concerns about the particular vaccines supplied, especially BioNTech’s efficacy and risks from Sinovac. While higher risk motivates longer preparation for vaccine uptake, higher levels of benefits from BioNTech could reduce hesitancy.

Effectiveness of Influenza Vaccination in Reducing Subsequent Antibiotic Prescribing in Young Children Attending Australian General Practices-A Case-Control Study

BACKGROUND

Vaccination against influenza may reduce antibiotic use, but data are limited and imprecise.

METHODS

We conducted a case-control study using deidentified data from a large national primary care database to evaluate antibiotic prescribing changes following influenza vaccination in children 1-4 years old attending primary care in the Australian 2018 and 2019 influenza seasons. Cases were prescribed β-lactam or macrolide antibiotics during the influenza season and controls were not. Influenza vaccination was documented in the medical records. Adjusted odds ratios for antibiotic prescribing according to influenza vaccination status were estimated using generalized estimating equations, controlling for age, asthma diagnosis, other vaccinations, practice visit frequency, and attendance week.

RESULTS

In 2018, 11 282 cases and 32 020 controls were eligible, and in 2019, 12 705 cases and 36 858 controls. Antibiotic prescriptions were less likely in vaccinated participants in 2018 (aOR, 0.65; 95% CI, 0.62-0.69) and 2019 (aOR, 0.78; 95% CI, 0.73-0.82) and did not vary by age, the number of GP visits, or prior prescribing of antibiotics. In the subgroup of children vaccinated in the preceding season, influenza vaccination was not associated with a reduction in antibiotic use (2018-aOR, 1.12; 95% CI, 0.90-1.39; 2019-aOR, 1.30; 95% CI, 1.16-1.46). From our estimates, potentially 100 000 antibiotic prescriptions could be avoided annually in Australia if all children in this age range were vaccinated.

CONCLUSIONS

Influenza vaccination may substantially reduce antibiotic prescribing among young children. This effect should be considered in the overall assessment of the costs and benefits of childhood influenza vaccination programs.

Molecular Insights into Coumarin Analogues as Antimicrobial Agents: Recent Developments in Drug Discovery

Simple Summary

Coumarins are a large family of benzopyrones, and more than 1300 coumarins have been reported to date. Natural, as well as synthetic, coumarins have demonstrated a diverse activity spectrum. On the other hand, the demands of the current health scenario witnessing morbidity and mortality due to microbial infections and multidrug-resistant bacterial strains, the well-reported phytochemical coumarin can be of interest. Some of the well-reported coumarin analogues as antimicrobial agents include β-lactum derivatives, coumarin-based 1,2,3-triazole compounds, the miconazole analogue, coumarin-substituted pyrazole hybrids, pyranocoumarin, coumarin−sulphonamide hybrids, pyranocoumarins, coumarin−sulphonamide derivatives, chromenylpyrazoles candidates, 3-amidocoumarins analogues, uracil−coumarin hybrids, indolinedione−coumarin hybrids, coumarin−imidazole hybrids, coumarin-fused pyrazolones and methyl thiazole derivatives, coumarin−theophylline hybrids, etc. In the present review, several methods for the synthesis of coumarin derivatives as antimicrobial agents are reported, along with structure−activity relationship (SAR) studies focusing on the developments reported since 2016.

Abstract

A major global health risk has been witnessed with the development of drug-resistant bacteria and multidrug-resistant pathogens linked to significant mortality. Coumarins are heterocyclic compounds belonging to the benzophenone class enriched in different plants. Coumarins and their derivatives have a wide range of biological activity, including antibacterial, anticoagulant, antioxidant, anti-inflammatory, antiviral, antitumour, and enzyme inhibitory effects. In the past few years, attempts have been reported towards the optimization, synthesis, and evaluation of novel coumarin analogues as antimicrobial agents. Several coumarin-based antibiotic hybrids have been developed, and the majority of them were reported to exhibit potential antibacterial effects. In the present work, studies reported from 2016 to 2020 about antimicrobial coumarin analogues are the focus. The diverse biological spectrum of coumarins can be attributed to their free radical scavenging abilities. In addition to various synthetic strategies developed, some of the structural features include a heterocyclic ring with electron-withdrawing/donating groups conjugated with the coumarin nucleus. The suggested structure−activity relationship (SAR) can provide insight into how coumarin hybrids can be rationally improved against multidrug-resistant bacteria. The present work demonstrates molecular insights for coumarin derivatives having antimicrobial properties from the recent past. The detailed SAR outcomes will benefit towards leading optimization during the discovery and development of novel antimicrobial therapeutics.

Exploiting genomics to mitigate the public health impact of antimicrobial resistance

Antimicrobial resistance (AMR) is a major global public health threat, which has been largely driven by the excessive use of antimicrobials. Control measures are urgently needed to slow the trajectory of AMR but are hampered by an incomplete understanding of the interplay between pathogens, AMR encoding genes, and mobile genetic elements at a microbial level. These factors, combined with the human, animal, and environmental interactions that underlie AMR dissemination at a population level, make for a highly complex landscape. Whole-genome sequencing (WGS) and, more recently, metagenomic analyses have greatly enhanced our understanding of these processes, and these approaches are informing mitigation strategies for how we better understand and control AMR. This review explores how WGS techniques have advanced global, national, and local AMR surveillance, and how this improved understanding is being applied to inform solutions, such as novel diagnostic methods that allow antimicrobial use to be optimised and vaccination strategies for better controlling AMR. We highlight some future opportunities for AMR control informed by genomic sequencing, along with the remaining challenges that must be overcome to fully realise the potential of WGS approaches for international AMR control.

Measuring the Link Between Vaccines and Antimicrobial Resistance in Low Resource Settings – Limitations and Opportunities in Direct and Indirect Assessments and Implications for Impact Studies

The importance of vaccines in combatting antimicrobial resistance (AMR) is commonly accepted. Although scientific reasoning supports the putative connection between vaccines and reduction of AMR, reliably measuring the magnitude and effect of vaccines on antimicrobial resistance is inherently challenging, especially in low resource settings. We review the intrinsic challenges in estimating the effect of vaccines on AMR and discuss the limitations and opportunities in current methods from the host, pathogen, and environment perspectives. We highlight advantages and pitfalls in different epidemiological study designs with a specific focus on impact studies in low resource settings and suggest how these perspectives could be considered in future research.

Addressing an urgent global public health need: Strategies to recover routine vaccination during the COVID-19 pandemic

Routine vaccination has been severely impacted by the COVID-19 pandemic, with 37% of countries reporting continuing disruptions to vaccination services into 2021. These programs have been faced with the challenges of achieving high vaccination coverage rates (VCRs), as well as identifying and vaccinating those who missed recommended doses since the pandemic began. Declines in VCRs, even for short periods, can lead to an increase in disease outbreaks, place additional pressure on health systems, and leave communities across the world at risk of death and disease from vaccine-preventable diseases.In the face of these disruptions, select governments are implementing promising approaches to address low VCRs, some of which represent innovative solutions to advance short-term, as well as longer-term program improvement. However, expanded action is urgently required to fully recover vaccination programs and strengthen vaccine system infrastructure. The COVID-19 pandemic provides a unique opportunity to modernize routine programs and corresponding infrastructure to meet today's and tomorrow's health challenges more effectively and efficiently. This can be achieved by prioritizing routine vaccination as an essential health service, improving access to vaccination across the life-course, strengthening data systems, ensuring sustainable immunization financing, and building confidence in vaccination.

Survey among Italian experts on existing vaccines' role in limiting antibiotic resistance

Antimicrobial resistance (AMR) is a major public health problem threatening to reverse the progress made against infectious diseases. The rapid increase of AMR exposes Italian hospitals at increased risk of untreatable infections. Vaccinations can potentially limit AMR by reducing the number of infected cases in need of antibiotics. We conducted a survey among Italian vaccine experts to record their opinion regarding the role of vaccinations against antibiotic resistance (ABR). Among 80 invited experts, 51 answered all questions. Most respondents were experts in hygiene and preventive medicine (56.9%) and aged >50 years (72.6%). ABR was a priority concern in the daily professional activity of 82.4% of respondents. Overall, 47.1% of respondents believed that all vaccinations included in the vaccination calendar played a role against ABR: 92.2% for pertussis vaccination followed by 88.2%, 74.5%, and 70.6% for meningococcus, measles, and varicella vaccinations, respectively. Almost all respondents agreed that the role of vaccinations against ABR should be clearly expressed in the national vaccination guidelines (96.1%) and Scientific Societies should take an explicit position on the issue (92.2%). These results show that Italian experts have recognized the vaccinations’ potential role in limiting ABR and guidelines from the appropriate scientific and governmental authorities are needed.

A review of current data to support decision making for introduction of next generation higher valency pneumococcal conjugate vaccination of immunocompetent older adults in the UK

INTRODUCTION

The burden of pneumococcal disease in older UK adults remains substantial. Higher valency pneumococcal conjugate vaccines (PCVs) are currently in development with adult formulations for two of these anticipated to become available in 2022. This article collates and reviews relevant candidate data now available that may be used to support cost effectiveness assessments of vaccinating immunocompetent UK adults aged ≥65-years with PCVs.

AREAS COVERED

This article uses published data from surveillance systems, randomized controlled trials and observational studies. It focuses on local data from the UK but where these are either limited or not available relevant global data are considered.

EXPERT OPINION

The body of relevant data now available suggests the UK is well placed to assess the cost effectiveness of vaccinating immunocompetent ≥65-year olds with new generation higher valency PCVs. Recent contemporary data provide important new and robust insights into the epidemiology of pneumococcal disease in older UK adults and help to address much of the uncertainty and data gaps associated with previous analyses. Using these data to make informed decisions about use of new higher valency PCVs for routine use in older adults will be important for public health in the UK.

Streptococcus pneumoniae genomic datasets from an Indian population describing pre-vaccine evolutionary epidemiology using a whole genome sequencing approach

Globally, India has a high burden of pneumococcal disease, and pneumococcal conjugate vaccine (PCV) has been rolled out in different phases across the country since May 2017 in the national infant immunization programme (NIP). To provide a baseline for assessing the impact of the vaccine on circulating pneumococci in India, genetic characterization of pneumococcal isolates detected prior to introduction of PCV would be helpful. Here we present a population genomic study of 480 Streptococcus pneumoniae isolates collected across India and from all age groups before vaccine introduction (2009–2017), including 294 isolates from pneumococcal disease and 186 collected through nasopharyngeal surveys. Population genetic structure, serotype and antimicrobial susceptibility profile were characterized and predicted from whole-genome sequencing data. Our findings revealed high levels of genetic diversity represented by 110 Global Pneumococcal Sequence Clusters (GPSCs) and 54 serotypes. Serotype 19F and GPSC1 (CC320) was the most common serotype and pneumococcal lineage, respectively. Coverage of PCV13 (Pfizer) and 10-valent Pneumosil (Serum Institute of India) serotypes in age groups of ≤2 and 3–5 years were 63–75 % and 60–69 %, respectively. Coverage of PPV23 (Merck) serotypes in age groups of ≥50 years was 62 % (98/158). Among the top five lineages causing disease, GPSC10 (CC230), which ranked second, is the only lineage that expressed both PCV13 (serotypes 3, 6A, 14, 19A and 19F) and non-PCV13 (7B, 13, 10A, 11A, 13, 15B/C, 22F, 24F) serotypes. It exhibited multidrug resistance and was the largest contributor (17 %, 18/103) of NVTs in the disease-causing population. Overall, 42 % (202/480) of isolates were penicillin-resistant (minimum inhibitory concentration ≥0.12 µg ml⁻¹) and 45 % (217/480) were multidrug-resistant. Nine GPSCs (GPSC1, 6, 9, 10, 13, 16, 43, 91, 376) were penicillin-resistant and among them six were multidrug-resistant. Pneumococci expressing PCV13 serotypes had a higher prevalence of antibiotic resistance. Sequencing of pneumococcal genomes has significantly improved our understanding of the biology of these bacteria. This study, describing the pneumococcal disease and carriage epidemiology pre-PCV introduction, demonstrates that 60–75 % of pneumococcal serotypes in children ≤5 years are covered by PCV13 and Pneumosil. Vaccination against pneumococci is very likely to reduce antibiotic resistance. A multidrug-resistant pneumococcal lineage, GPSC10 (CC230), is a high-risk clone that could mediate serotype replacement.