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Cellular and Molecular Biology... Jan 2022Streptococcus pneumoniae is the bacterium that causes pneumococcal disease which often results in pneumonia, meningitis, otitis media, septicemia and sinusitis.... (Review)
Review
Streptococcus pneumoniae is the bacterium that causes pneumococcal disease which often results in pneumonia, meningitis, otitis media, septicemia and sinusitis. Pneumonia, particularly, is a significant cause of worldwide morbidity and a global health burden as well. Treatment often relies on antimicrobials, to which the pathogen is frequently mutating and rendering infective. Consequently, vaccination is the most effective approach in dealing with pneumococcal antimicrobial resistance (AMR). Unfortunately, the current pneumococcal polysaccharide and conjugate vaccines have a narrow serotype coverage. Therefore, the current need for vaccines with a broader serotype coverage cannot be overstated. Pneumococcal Surface Protein A and C are potential vaccine candidate antigens present in over 90% of the strains from clinical isolates as well as laboratory non-encapsulated strains. Pneumococcal Surface Protein A is an active virulent factor that pneumococci use to evade complement-mediated host immune responses and has been shown to elicit immune responses against pneumococcal infections. This review explores the potential utilization of Pneumococcal Surface Protein A to immunize against S. pneumoniae.
Topics: Bacterial Proteins; Humans; Pneumococcal Infections; Pneumococcal Vaccines; Streptococcus pneumoniae
PubMed: 35809277
DOI: 10.14715/cmb/2021.67.4.32 -
Journal of Clinical GastroenterologyGuidelines for inflammatory bowel disease (IBD) patients receiving immunosuppression encouraged both the pneumococcal polysaccharide vaccine (PPSV23) and the...
BACKGROUND
Guidelines for inflammatory bowel disease (IBD) patients receiving immunosuppression encouraged both the pneumococcal polysaccharide vaccine (PPSV23) and the pneumococcal conjugate vaccine (PCV13). We aimed to evaluate which pneumococcal vaccines are recommended and administered, and to understand provider and IBD patient knowledge regarding pneumococcal vaccinations.
METHODS
We performed a retrospective, cross-sectional analysis of 357 adult IBD patients on immunosuppression in our health care system. Patient demographics and clinical characteristics were collected. The primary outcome was rate of documented vaccinations recommended by providers; the secondary outcome was rate of receipt of the vaccines. We identified factors associated with receipt of any pneumococcal vaccine through multivariable logistic regression. We also performed provider and IBD patient surveys to understand provider and patient knowledge regarding pneumococcal vaccines. We used χ 2 and Fisher exact tests to assess survey responses.
RESULTS
Fifty seven percent of IBD patients had any pneumococcal vaccination recommended and 35% had recommendations for both PPSV23 and PCV13. Forty percent received any pneumococcal vaccine and 18% received both vaccines. In multivariable analyses, increasing age (adjusted odds ratio: 1.03, 95% CI: 1.01-1.05) was associated with receipt of any pneumococcal vaccine, after adjusting for gender, race, insurance, disease activity, and time seen in our gastroenterology clinics. In the survey study, on average, 59% of providers correctly answered questions regarding pneumococcal vaccination indications.
CONCLUSION
In our health care system, while recommendation for any pneumococcal vaccination was >50%, receipt of both PPSV23 and PCV13 was low. Simplified vaccine regimens (ie, PCV20) will likely improve vaccination rates.
Topics: Adult; Humans; Retrospective Studies; Cross-Sectional Studies; Vaccination; Pneumococcal Vaccines; Inflammatory Bowel Diseases
PubMed: 36728018
DOI: 10.1097/MCG.0000000000001783 -
Human Vaccines & Immunotherapeutics Nov 2022The 23-valent pneumococcal polysaccharide vaccine (PPSV-23) is the only approved vaccine for pneumococcal diseases in elderly Chinese population. Though regional studies... (Review)
Review
The 23-valent pneumococcal polysaccharide vaccine (PPSV-23) is the only approved vaccine for pneumococcal diseases in elderly Chinese population. Though regional studies explored the PPSV-23 vaccination coverage rates and influencing factors in China, a large-scale, nation-wide epidemiological surveillance studies to understand the different factors impeding pneumococcal vaccination rate are required. Hence, this review summarized PPSV-23 coverage rate, analyzed and identified vaccination influencing factors among elderly population across China by exploring articles published in CNKI, Wanfang and PubMed databases. Pneumococcal vaccination coverage rate was found to be low at around 1.23%~42.10% in China. Co-morbidities, knowledge, attitude, perception toward pneumonia and PPSV-23, education level, socio-economic disparities, health education and local policies were some of the factors associated with vaccination willingness among elderly Chinese population. Interventions or policies like government funding, subsidies, inclusion of PPSV-23 in medical insurance, or systematic encouragement from HCPs as key strategies should be implemented to encourage vaccination.
Topics: Adult; Aged; Humans; East Asian People; Pneumococcal Vaccines; Pneumococcal Infections; Vaccination; Streptococcus pneumoniae
PubMed: 36379017
DOI: 10.1080/21645515.2022.2139123 -
Expert Review of Vaccines Jun 2021Immunosenescence is a normal biologic process involving deterioration of protective immune responses. Consequently, older adults experience increased risk of infectious... (Review)
Review
INTRODUCTION
Immunosenescence is a normal biologic process involving deterioration of protective immune responses. Consequently, older adults experience increased risk of infectious diseases, particularly pneumonia, and its leading bacterial cause, . Pneumococcal vaccine recommendations are often limited to adults with specific medical conditions despite similar disease risks among older adults due to immunosenescence.
AREAS COVERED
This article reviews epidemiologic, biologic, and clinical evidence supporting the consideration of older age due to immunosenescence as an immunocompromising condition for the purpose of pneumococcal vaccine policy and the role vaccination can play in healthy aging.
EXPERT OPINION
Epidemiologic and biologic evidence suggest that pneumococcal disease risk increases with age and is comparable for healthy older adults and younger adults with immunocompromising conditions. Because immunocompromising conditions are already indicated for pneumococcal conjugate vaccines (PCVs), a comprehensive public health strategy would also recognize immunosenescence. Moreover, older persons should be vaccinated before reaching the highest risk ages, consistent with the approach for other immunocompromising conditions. To facilitate PCV use among older adults, vaccine technical committees (VTCs) could classify older age as an immunocompromising condition based on the process of immunosenescence. With global aging, VTCs will need to consider immunosenescence and vaccine use during healthy aging.
Topics: Aged; Aged, 80 and over; Humans; Pneumococcal Infections; Pneumococcal Vaccines; Policy; Streptococcus pneumoniae; Vaccination; Vaccines, Conjugate
PubMed: 34233558
DOI: 10.1080/14760584.2021.1921579 -
Vaccine Jun 2021The implementation of polysaccharide-based vaccines has massively reduced the incidence of invasive pneumococcal diseases. However, there is great concern regarding...
The implementation of polysaccharide-based vaccines has massively reduced the incidence of invasive pneumococcal diseases. However, there is great concern regarding serotype replacement and the increase in antibiotic resistant strains expressing non-vaccine capsular types. In addition, conjugate vaccines have high production costs, a limiting factor for their implementation in mass immunization programs in developing countries. These limitations have prompted the development of novel vaccine strategies for prevention of Streptococcus pneumoniae infections. The use of conserved pneumococcal antigens such as recombinant proteins or protein fragments presents an interesting serotype-independent alternative. Pht is a family of surface-exposed proteins which have been evaluated as potential vaccine candidates with encouraging results. The present work investigated the immune responses elicited by subcutaneous immunization of mice with the polyhistidine triad protein D (PhtD) and its amino and carboxyl terminal fragments. The proteins were immunogenic and protective against pneumococcal sepsis in mice. Antibodies raised against PhtD increased complement C3b deposition on the pneumococcal surface, mainly mediated by the alternative pathway. Sera from mice immunized with PhtD and PhtD_Cter promoted an increase in bacterial uptake by mouse phagocytes. The interaction of PhtD with the complement system regulator factor H was investigated in silico and in vitro by ELISA and western blot, confirming PhtD as a factor-H binding protein. Our results support the inclusion of PhtD and more specifically, its C-terminal fragment in a multicomponent serotype independent vaccine and suggests a role for the complement system in PhtD-mediated protection.
Topics: Animals; Antibodies, Bacterial; Bacteremia; Bacterial Proteins; Mice; Pneumococcal Infections; Pneumococcal Vaccines
PubMed: 34045100
DOI: 10.1016/j.vaccine.2021.04.068 -
Clinical Microbiology and Infection :... Jan 2020Of over 90 serotypes of Streptococcus pneumoniae, only seven were included in the first pneumococcal conjugate vaccine (PCV). While PCV reduced the disease incidence, in... (Review)
Review
BACKGROUND
Of over 90 serotypes of Streptococcus pneumoniae, only seven were included in the first pneumococcal conjugate vaccine (PCV). While PCV reduced the disease incidence, in part because of a herd immunity effect, a replacement effect was observed whereby disease was increasingly caused by serotypes not included in the vaccine. Dynamic transmission models can account for these effects to describe post-vaccination scenarios, whereas economic evaluations can enable decision-makers to compare vaccines of increasing valency for implementation.
AIM
The aim of this review was to examine epidemiological and economic models and their assumptions for their potential contributions to future research and immunisation policy.
SOURCES
Pubmed, Scopus, Ovid, ISI Web of Knowledge, Centre of Reviews and Dissemination (CRD) databases were searched.
CONTENT
Twenty-three dynamic transmission models and 21 economic models were retrieved and reviewed. Published models employed various templates, revealing several key uncertainties regarding the biology and epidemiology of pneumococcal infection. While models suggested that PCVs will reduce the burden of disease, the extent to which they are predicted to do so depended on various assumptions regarding features of pneumococcal infection and epidemiology that governed PCV cost-effectiveness as well. Such features include the duration of protection and competitive interactions between serotypes, which are unclear at present, but which directly relate to herd immunity and serotype replacement.
IMPLICATIONS
Economic evaluations are not typically based on transmission dynamic models and hence omit indirect herd immunity effects. The two tools could be used in conjunction to inform decision-makers on vaccine implementation, but so far there have been few attempts to build economic evaluations on transmission dynamic models, and none in this field. Future directions for research could include studies to evaluate key parameters for the models involving herd immunity, serotype competition and the natural history of infection.
Topics: Cost-Benefit Analysis; Decision Support Techniques; Humans; Immunity, Herd; Models, Economic; Pneumococcal Infections; Pneumococcal Vaccines; Serogroup; Streptococcus pneumoniae; Vaccination; Vaccines, Conjugate
PubMed: 31055164
DOI: 10.1016/j.cmi.2019.04.026 -
Vaccine Aug 2023In the province of Quebec, Canada, a 2 + 1 dose pneumococcal conjugate vaccine (PCV) program for children was implemented in 2004. PCV7 was replaced by PCV10 in 2009,...
In the province of Quebec, Canada, a 2 + 1 dose pneumococcal conjugate vaccine (PCV) program for children was implemented in 2004. PCV7 was replaced by PCV10 in 2009, by PCV13 in 2011 and by PCV10 in 2018, without catch-up in all instances. The objective was to estimate PCV13 effectiveness to prevent serotype 3 invasive pneumococcal disease in children aged less than 5 years, using 2010-2018 mandatory notification and laboratory surveillance data, an indirect cohort design and multivariate logistic regression models. A total of 29 cases of serotype 3 and 290 non-vaccine serotype cases as controls were analysed. Overall vaccine effectiveness (≥1 dose) was estimated at 59% [-39% to 88%]. During the first year after the last dose effectivness was 88% [47% to 97%] whereas no protection was observed thereafter. There was no trend towards increased effectiveness with the number of doses. PCV13 protection against serotype 3 IPD seems to be short-lived.
Topics: Humans; Child; Infant; Quebec; Vaccines, Conjugate; Serogroup; Streptococcus pneumoniae; Heptavalent Pneumococcal Conjugate Vaccine; Pneumococcal Infections; Pneumococcal Vaccines; Canada
PubMed: 37524629
DOI: 10.1016/j.vaccine.2023.07.049 -
Expert Review of Vaccines Feb 2022The pneumococcal non-typeable protein D-conjugate vaccine (PHiD-CV/PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) protect against vaccine-serotype invasive...
INTRODUCTION
The pneumococcal non-typeable protein D-conjugate vaccine (PHiD-CV/PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) protect against vaccine-serotype invasive pneumococcal disease (VT IPD). However, VT IPD can still occur in fully or partially vaccinated children (vaccine failure or breakthrough). We performed a systematic review of vaccine failures and breakthrough IPD with PCV10 and PCV13 in ≤5-year-olds.
AREAS COVERED
We searched Scopus/Medline/EMBASE to retrieve articles/abstracts published between 1/2008-7/2019. We excluded reports only including data from ≥6-year-olds, exclusively assessing PCV7-vaccinated children or children with comorbidities. Twenty-six reports (20 PCV13, 1 PCV10, 5 both), covering studies with various designs in six continents, using different schedules, were included. Collectively, they reported 469 VT IPD cases classified as vaccine failures and 403 as breakthrough. Vaccine failure and breakthrough rates were low: 8.4% and 9.3%, respectively, of all IPD in vaccinated children, consistent with the vaccines' high effectiveness. The main serotypes associated with vaccine failure/breakthrough were 19A, 3 and 19F for PCV13 and 14, 6B and vaccine-related 19A and 6A for PCV10.
EXPERT OPINION
As we move to vaccines with more serotypes, it is not only important to consider which serotypes are added, but also monitor and address incomplete protection against specific serotypes.
Topics: Child; Child, Preschool; Haemophilus influenzae; Humans; Infant; Pneumococcal Infections; Pneumococcal Vaccines; Serogroup; Streptococcus pneumoniae; Vaccines, Conjugate
PubMed: 34882050
DOI: 10.1080/14760584.2022.2012455 -
Vaccine Jul 2022The covalent attachment of a bacterial-derived capsular polysaccharide to protein is of critical importance in transforming the polysaccharide from an antigen with...
The covalent attachment of a bacterial-derived capsular polysaccharide to protein is of critical importance in transforming the polysaccharide from an antigen with limited immunogenicity in infants and older adults to an antigen that can prevent potentially fatal disease. For a polysaccharide-protein conjugate vaccine (PCV) candidate to be successful, it must be sufficiently stable. Chemical breakage of carbohydrate bonds in the polysaccharide may result in the reduction of "conjugate dose" and could negatively impact immunogenicity and the ability of the vaccine to prime for memory responses. Therefore, development of analytical tools to monitor the integrity of a polysaccharide-protein conjugate (glycoconjugate) vaccine is of practical significance. In this work, reducing SDS-PAGE, Intrinsic Protein Fluorescence Spectroscopy (IPFS), Differential Scanning Fluorimetry (DSF) were evaluated methods to study the impact of time, temperature, and formulation composition on the stability of a glycoconjugate vaccine prepared by multisite coupling of polysaccharide to a carrier protein. In addition, an automated capillary Western system was also evaluated to study the impact of storage on glycoconjugate vaccine stability. Two streptococcus pneumoniae polysaccharide-protein conjugates (serotype 3 and serotype 19A) were chosen to examine their physicochemical stability when formulated as a single antigen vaccine. While all methods require only a small amount of test article and can test multiple samples per assay run, automated capillary Western has the additional advantage of being highly sensitive even at low concentrations in complex vaccine formulations that contain aluminum adjuvant and multiple antigens. Results suggest that automated capillary Western is stability-indicating and may be an effective analytical technology tool for the formulation development of a multivalent glycoconjugate vaccine.
Topics: Aged; Antibodies, Bacterial; Glycoconjugates; Humans; Industrial Development; Infant; Pneumococcal Infections; Pneumococcal Vaccines; Polysaccharides, Bacterial; Vaccines, Conjugate
PubMed: 35688729
DOI: 10.1016/j.vaccine.2022.05.056 -
Human Vaccines & Immunotherapeutics Apr 2021Limited data exist regarding pneumococcal vaccination coverage among the elderly in Middle Eastern countries including Jordan. The pharmacists' role in improving vaccine... (Randomized Controlled Trial)
Randomized Controlled Trial
Limited data exist regarding pneumococcal vaccination coverage among the elderly in Middle Eastern countries including Jordan. The pharmacists' role in improving vaccine acceptance has become increasingly evident. Yet, large-scale studies of the assessment of the pharmacists' role on pneumococcal vaccines acceptance among the elderly are scarce. Hence, we assessed for the first time the current state of knowledge and pneumococcal vaccination coverage among the elderly and the role of pharmacist-led educational intervention on the attitude, awareness, vaccine acceptance, and prompts for physician consultation regarding pneumococcal vaccines in Jordan. This interventional study enrolled 916 randomly selected adults aged ≥ 65 years in Amman, Jordan. We showed that only 3.9% of the participants have ever heard about pneumococcal disease with 0.5% vaccination coverage. Immediately after educational intervention, 21.7% of the participants perceived pneumococcal disease as a threat, 52.1% of them believed in the importance of the vaccine, and 93.9% of them were willing to consult a physician in this regard. At a two-month follow-up, 30.5% had a positive attitude toward the vaccine and 36% consulted their physician regarding the vaccine. Vaccination coverage was significantly increased to 1.9% ( value = 0.008). The main obstacles against vaccination were a negative attitude and that physicians had not recommended the vaccine. Vaccine uptake was significantly associated with physician consultation ( value = 0.011). Insurance, employment, attitude, and reading the booklet significantly predicted physician consultation. In conclusion, very low pneumococcal vaccination coverage was observed among the elderly in Jordan. Enrollment of pharmacists in immunization education and recommendation is suggested to improve pneumococcal vaccine coverage among the elderly in Jordan.
Topics: Adult; Aged; Humans; Jordan; Pharmacists; Pneumococcal Infections; Pneumococcal Vaccines; Vaccination
PubMed: 32931712
DOI: 10.1080/21645515.2020.1802973