scholarly journals Differences in Pneumococcal Serotype Replacement in Individuals with and without Underlying Medical Conditions

2018 ◽  
Author(s):  
Daniel M. Weinberger ◽  
Joshua L Warren ◽  
Tine Dalby ◽  
Eugene D. Shapiro ◽  
Valentiner Branth ◽  
...  

ABSTRACTBackgroundPneumococcal conjugate vaccines (PCVs) have had a well-documented impact on the incidence of invasive pneumococcal disease (IPD) worldwide. However, declines in IPD due to vaccine-targeted serotypes have been partially offset by increases in IPD due to non-vaccine serotypes. The goal of this study was to quantify serotype-specific changes in the incidence of IPD that occurred in different age groups, with or without certain co-morbidities, following the introduction of PCV7 and PCV13 in the childhood vaccination program in Denmark.MethodsWe used nationwide surveillance data for IPD in Denmark and a hierarchical Bayesian regression framework to estimate changes in the incidence of IPD associated with the introduction of PCV7 (2007) and PCV13 (2010) while controlling for serotype-specific epidemic cycles and unrelated secular trends.Results and ConclusionsFollowing the introduction of PCV7 and 13 in children, the net impact of serotype replacement varied considerably by age group and the presence of comorbid conditions. Serotype replacement offset a greater fraction of the decline in vaccine-targeted serotypes following the introduction of PCV7 compared with the period following the introduction of PCV13. Differences in the magnitude of serotype replacement were due to variations in the incidence of non-vaccine serotypes in the different risk groups before the introduction of PCV7 and PCV13. The relative increases in the incidence of IPD caused by non-vaccine serotypes did not differ appreciably in the post-vaccination period. Serotype replacement offset a greater proportion of the benefit of PCVs in strata in which the non-vaccine serotypes comprised a larger proportion of cases prior to the introduction of the vaccines. These findings could help to predict the impact of next-generation conjugate vaccines in specific risk groups.

2013 ◽  
Vol 10 (89) ◽  
pp. 20130786 ◽  
Author(s):  
Christian Bottomley ◽  
Anna Roca ◽  
Philip C. Hill ◽  
Brian Greenwood ◽  
Valerie Isham

A number of childhood vaccination programmes have recently introduced vaccination against Streptococcus pneumoniae , the pneumococcus, a major cause of pneumonia and meningitis. The pneumococcal conjugate vaccines (PCVs) that are currently in use only protect against some serotypes of the bacterium, and there is now strong evidence that those serotypes not included in the vaccine increase in prevalence among most vaccinated populations. We present a mathematical model for the dynamics of nasopharyngeal carriage of S. pneumoniae that allows for carriage with multiple serotypes. The model is used to predict the prevalence of vaccine type (VT) and non-VT (NVT) serotypes following the introduction of PCV. Parameter estimates for the model are obtained by maximum likelihood using pre-vaccination data from The Gambia. The model predicts that low (1, 6A and 9V) and medium (4, 5, 7F, 14, 18C, 19A and 19F) prevalence serotypes can be eliminated through vaccination, but that the overall prevalence of carriage will be reduced only slightly because of an increase in the prevalence of NVT serotypes. Serotype replacement will be sequential, with high and medium prevalence NVT serotypes dominating initially, followed by an increase of serotypes of low prevalence. We examine the impact of a hypothetical vaccine that provides partial protection against all serotypes, and find that this reduces overall carriage, but is unable to eliminate low or medium prevalence serotypes.


2018 ◽  
Vol 69 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Daniel M Weinberger ◽  
Joshua L Warren ◽  
Tine Dalby ◽  
Eugene D Shapiro ◽  
Palle Valentiner-Branth ◽  
...  

2020 ◽  
Author(s):  
Maile T. Phillips ◽  
Joshua L. Warren ◽  
Noga Givon-Lavi ◽  
Adrienn Tothpal ◽  
Gili Regev-Yochay ◽  
...  

ABSTRACTStreptococcus pneumoniae remains a leading cause of morbidity and mortality. Pneumococcal conjugate vaccines (PCVs) are effective but target only a fraction of the more than 90 pneumococcal serotypes. As a result, the introduction of PCVs has been followed by the emergence of non-vaccine serotypes. With higher-valency PCVs currently under development, there is a need to understand and predict patterns of serotype replacement to anticipate future changes. In this study, we evaluated patterns of change in serotype prevalence post-PCV introduction in Israel. We found that the assumption that non-vaccine serotypes increase by the same proportion overestimates changes in serotype prevalence in Jewish and Bedouin children. Furthermore, pre-vaccine prevalence was positively associated with increases in prevalence over the study period. From our analyses, serotypes 12F, 8, 16F, 33F, 9N, 7B, 10A, 22F, 24F, and 17F were estimated to have gained the most cases of invasive pneumococcal disease through serotype replacement in the Jewish population. However, this model also failed to quantify some additional cases gained, suggesting that changes in carriage in children alone may be insufficient to explain serotype replacement in disease. Understanding of serotype replacement is important as higher-valency vaccines are introduced.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alessandra Løchen ◽  
Nicholas J. Croucher ◽  
Roy M. Anderson

Abstract Streptococcus pneumoniae is a significant cause of otitis media, pneumonia, and meningitis. Only seven of the approximately 100 serotypes were initially included in the pneumococcal polysaccharide conjugate vaccine (PCV) in 2000 before it was expanded in subsequent years. Although the invasive pneumococcal disease (IPD) incidence due to vaccine serotypes (VT) has declined, partial replacement by non-vaccine serotypes (NVT) was observed following widespread vaccine uptake. We conducted a trend analysis assembling the available evidence for PCV impact on European, North American and Australian national IPD. Significant effectiveness against VT IPD in infants was observed, although the impact on national IPD incidence varied internationally due to serotype replacement. Currently, NVT serotypes 8, 9N, 15A and 23B are increasing in the countries assessed, although a variety of other NVTs are affecting each country and age group. Despite these common emerging serotypes, there has not been a dominant IPD serotype post-vaccination as there was pre-vaccination (serotype 14) or post-PCV7 (serotype 19A), suggesting that future vaccines with additional serotypes will be less effective at targeting and reducing IPD in global populations than previous PCVs. The rise of diverse NVTs in all settings’ top-ranked IPD-causing serotypes emphasizes the urgent need for surveillance data on serotype distribution and serotype-specific invasiveness post-vaccination to facilitate decision making concerning both expanding current vaccination programmes and increasing vaccine valency.


Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 278
Author(s):  
Gabriela B. C. Colichio ◽  
Giuliana S. Oliveira ◽  
Tasson C. Rodrigues ◽  
Maria Leonor S. Oliveira ◽  
Eliane N. Miyaji

Widespread use of pneumococcal conjugate vaccines (PCVs) has led to substitution of vaccine-type (VT) strains by non-vaccine type (NVT) strains in nasopharyngeal carriage. We compared the efficacy of PCV13 and a nasal protein formulation containing pneumococcal surface protein A (PspA) adjuvanted with the whole-cell pertussis vaccine (wP) in the protection against co-colonization challenge models in mice with VT and NVT strains expressing different PspAs. Immunized mice were challenged with two different mixtures: i. VT4 (PspA3) + NVT33 (PspA1) and ii. VT23F (PspA2) + NVT15B/C (PspA4). Results from the first mixture showed a reduction in loads of VT4 strain in the nasopharynx of mice immunized with PCV13. A statistical difference between the loads of the VT and NVT strains was observed, indicating a competitive advantage for the NVT strain in PCV13-immunized animals. In the second mixture, no reduction was observed for the VT23F strain, probably due to low levels of anti-23F polysaccharide IgG induced by PCV13. Interestingly, a combination of the PspA formulation containing wP with PCV13 led to a reduction in colonization with both strains of the two mixtures tested, similar to the groups immunized nasally with wP or PspA plus wP. These results indicate that a combination of vaccines may be a useful strategy to overcome pneumococcal serotype replacement.


2021 ◽  
Vol 66 ◽  
Author(s):  
Yael Rachamin ◽  
Oliver Senn ◽  
Sven Streit ◽  
Julie Dubois ◽  
Michael J. Deml ◽  
...  

Objectives: We aimed to explore the impact of the Swiss shutdown in spring 2020 on the intensity of health services use in general practice.Methods: Based on an electronic medical records database, we built one patient cohort each for January-June 2019 (control, 173,523 patients) and 2020 (179,086 patients). We used linear regression to model weekly consultation counts and blood pressure (BP) and glycated hemoglobin (HbA1c) measurement counts per 100 patients and predicted non-shutdown values. Analyses were repeated for selected at-risk groups and different age groups.Results: During the shutdown, weekly consultation counts were lower than predicted by −17.2% (total population), −16.5% (patients with hypertension), −17.5% (diabetes), −17.6% (cardiovascular disease), −15.7% (patients aged <60 years), −20.4% (60–80 years), and −14.5% (>80 years). Weekly BP counts were reduced by −35.3% (total population) and −35.0% (hypertension), and HbA1c counts by −33.2% (total population) and −29.8% (diabetes). p-values <0.001 for all reported estimates.Conclusion: Our results document consequential decreases in consultation counts and chronic disease monitoring during the shutdown. It is crucial that health systems remain able to meet non-COVID-19-related health care needs.


2017 ◽  
Vol 41 ◽  
pp. 1
Author(s):  
Lucia Helena De Oliveira ◽  
Barbara Jauregui ◽  
Ana Flavia Carvalho ◽  
Norberto Giglio

Objectives.To summarize and critically evaluate the evidence on the impact and effectiveness of meningococcal vaccination programs around the world in order to inform decisionmaking in Latin America and the Caribbean.Methods.A review of the literature was conducted following several components of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed Central® was searched for papers published in any language from January 1999 – March 2017.Results.In all, 32 studies were included, most of which evaluated the meningococcal C conjugate vaccine. Fourteen studies measured effectiveness and 30 measured impact. The effectiveness of polysaccharide vaccines was 65% – 83.7% (different age groups), while the effectiveness of the conjugate vaccines was 66% – 100%. Incidence decline of laboratory-confirmed meningococcal disease for the conjugate vaccine ranged from 77% – 100% among different ages groups. The only study that evaluated the protein subunit vaccine reported a vaccine effectiveness of 82.9%.Conclusions.The studies reviewed show impact and effectiveness of both polysaccharide vaccines and conjugate vaccines on vaccine-serogroup meningococcal disease. The conjugate vaccines, however, show higher impact and effectiveness with longer-lasting protection over the polysaccharide vaccines. Given the variance in potential use of a meningococcal vaccine, epidemiological surveillance systems should be strengthened to inform national decisions.


PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262225
Author(s):  
Sweta M. Patel ◽  
Yazdani B. Shaik-Dasthagirisaheb ◽  
Morgan Congdon ◽  
Rebecca R. Young ◽  
Mohamed Z. Patel ◽  
...  

Pneumococcal conjugate vaccines reduce the burden of invasive pneumococcal disease, but the sustained effect of these vaccines can be diminished by an increase in disease caused by non-vaccine serotypes. To describe pneumococcal serotype epidemiology in Botswana following introduction of 13-valent pneumococcal conjugate vaccine (PCV-13) in July 2012, we performed molecular serotyping of 268 pneumococcal strains isolated from 221 children between 2012 and 2017. The median (interquartile range) age of the children included in this analysis was 6 (3,12) months. Fifty-nine percent of the children had received at least one dose of PCV-13 and 35% were fully vaccinated with PCV-13. While colonization by vaccine serotypes steadily declined following PCV-13 introduction, 25% of strains isolated more than 3 years after vaccine introduction were PCV-13 serotypes. We also observed an increase in colonization by non-vaccine serotypes 21 and 23B, which have been associated with invasive pneumococcal disease and antibiotic resistance in other settings.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
C Chiavenna ◽  
A Presanis ◽  
A Charlett ◽  
S Ladhani ◽  
D De Angelis

Abstract Background Increased incidence of invasive pneumococcal disease (IPD) attributable to non-vaccine serotypes (NVT) has been reported in several countries following introduction of PCV7 and PCV13 vaccines, concurrently with a reduction in vaccine-type IPD. Such serotype replacement has, importantly, emerged in England, offsetting the benefit of PCV introduction. We scrutinise most recent findings to assess if the estimated increase in NVT disease might result from surveillance artefacts. Methods Using IPD surveillance for 2000-2018, we estimate the impact of PCV7 and PCV13 introduction on age-serotype-specific incidence rates through a synthetic control regression model, building counterfactuals by combining age-specific incidences reported for pathogens unaffected by PCVs. Results Following the introduction of PCV7 and PCV13 (pre-2006 vs post-2011), total IPD incidence declined by 57% and by 76% in children younger than 5. PCV7-IPD decreased by 93% in all age groups, whereas PCV13-IPD declined by 68% since PCV13 was introduced. Importantly, NVT-IPD increased by 43% after PCV7, with non-significant statistical increases in most age groups. Conclusions Through appropriate statistical modelling, we disentangled the impact of vaccine and improved surveillance on the changes in IPD incidence rates. By controlling for the confounding effects of improved surveillance, we are able to estimate a lower serotype replacement. Key messages Pneumococcal vaccine has been beneficial despite serotype replacement. Adequate statistical methods are needed to disentangle the two phenomena.


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