Polysaccharide Vaccine Research Articles

Novel pneumococcal capsule type 33E results from the inactivation of glycosyltransferase WciE in vaccine type 33F

The polysaccharide (PS) capsule is essential for immune evasion and virulence of Streptococcus pneumoniae. Existing pneumococcal vaccines are designed to elicit anticapsule antibodies; however, the effectiveness of these vaccines is being challenged by the emergence of new capsule types or variants. Herein, we characterize a newly discovered capsule type, 33E, that appears to have repeatedly emerged from vaccine type 33F via an inactivation mutation in the capsule glycosyltransferase gene, wciE. Structural analysis demonstrated that 33E and 33F share an identical repeat unit backbone [→5)-β-D-Galf2Ac-(1→3)-β-D-Galp-(1→3)-α-D-Galp-(1→3)-β-D-Galf-(1→3)-β-D-Glcp-(1→], except that a galactose (α-D-Galp) branch is present in 33F but not in 33E. Though the two capsule types were indistinguishable using conventional typing methods, the monoclonal antibody Hyp33FM1 selectively bound 33F but not 33E pneumococci. Further, we confirmed that wciE encodes a glycosyltransferase that catalyzes the addition of the branching α-D-Galp and that its inactivation in 33F strains results in the expression of the 33E capsule type. Though 33F and 33E share a structural and antigenic similarity, our pilot study suggested that immunization with a 23-valent pneumococcal PS vaccine containing 33F PS did not significantly elicit cross-opsonic antibodies to 33E. New conjugate vaccines that target capsule type 33F may not necessarily protect against 33E. Therefore, studies of new conjugate vaccines require knowledge of the newly identified capsule type 33E and reliable pneumococcal typing methods capable of distinguishing it from 33F.

Cost-utility analysis of the use of the 20-valent anti-pneumococcal vaccine (PCV20) in adults older than 60 years in Spain

Background and objectivesA cost-utility analysis was conducted to assess the efficiency of implementing a PCV20 vaccination strategy in the Spanish adult population older than 60 years, for the prevention of non-bacteremic pneumococcalpneumonia (NBP) and invasive pneumococcal disease (IPD). MethodsA Markov model, with annual cycles and a time horizon of 10 years was used. The analysis population was stratified by age and risk groups. The comparator was the sequential vaccination with the 15-valent pneumococcal conjugate vaccine (PCV15) followed by one dose of the pneumococcal polysaccharide vaccine (PPV23). The base case analysis was performed from the National Healthcare System (NHS) perspective including direct costs (€2018) and applying a discount of 3% to future costs and outcomes. Alternative scenarios explored a shorter time horizon (5 years), the societal perspective and other available vaccination strategies. All the parameters and assumptions were validated by a panel of experts. To evaluate the robustness of the model, deterministic and probabilistic sensitivity analyses (PSA) were carried out. ResultsThe results of the study showed that the vaccination strategy with PCV20 is a dominant option compared to the sequential regimen (PCV15 + PPSV23), resulting in direct cost savings of €85.7 M over 10 years, with a small increase in quality-adjusted life years (QALYs). PCV20 vaccination avoided 2,161 cases of IPD, 19,470 of NBP and 3,396 deaths and according to the PSA, the probability of PCV20 being cost-effective compared to a sequential regimen (PCV15 + PPSV23) was 100%. Conclusions/RecommendationsIn the Spanish adult population older than 60 years, the vaccination strategy with one dose of PCV20 is more effective and less expensive (dominant) than vaccination with a sequential schedule with PCV15 and PPSV23.

Pneumococcal carriage, serotype distribution, and antimicrobial susceptibility in Papua New Guinean children vaccinated with PCV10 or PCV13 in a head-to-head trial

BackgroundChildren in Papua New Guinea (PNG) are at high risk of pneumococcal infections. We investigated pneumococcal carriage rates, serotype distribution, and antimicrobial susceptibility in PNG children after vaccination with 10-valent or 13-valent pneumococcal conjugate vaccines (PCV10; PCV13). MethodsInfants (N = 262) were randomized to receive 3 doses of PCV10 or PCV13 at 1-2-3 months of age, followed by pneumococcal polysaccharide vaccination (PPV) or no PPV at 9 months of age. Nasopharyngeal swabs (NPS) collected at ages 1, 4, 9, 10, 23 and 24 months were cultured using standard bacteriological procedures. Morphologically distinct Streptococcus pneumoniae colonies were serotyped by the Quellung reaction. Antimicrobial susceptibility was determined by Kirby-Bauer disc diffusion and minimum inhibitory concentration (MIC). ResultsS. pneumoniae was isolated from 883/1063 NPS collected at 1–23 months of age, including 820 serotypeable (64 different serotypes) and 144 non-serotypeable isolates. At age 23 months, 93.6% (95%CI 86.6–97.6%) of PCV10 recipients and 88.6% (95%CI 80.1–94.4%) of PCV13 recipients were pneumococcal carriers, with higher carriage of PCV10 serotypes by PCV10 recipients (19.8%, 95%CI 12.2–29.5) than PCV13 recipients (9.3%, 95%CI 4.1–17.3) (p = 0.049). There were no other statistically significant differences between PCV10 and PCV13 recipients and children receiving PPV or no PPV. Nearly half (45.6%) of carried pneumococci were non-susceptible to penicillin based on the meningitis breakpoint (MIC ≥ 0.12 µg/mL), but resistance was rare (1.1%) using the non-meningitis cut-off (MIC ≥ 8 µg/mL). Non-susceptibility to trimethoprim-sulfamethoxazole (SXT) was common: 23.2% of isolates showed intermediate resistance (MIC 1/19–2/38 µg/mL) and 16.9% full resistance (MIC ≥ 4/76 µg/mL). PCV serotypes 14 and 19A were commonly non-susceptible to both penicillin (14, 97%; 19A, 70%) and SXT (14, 97%; 19A, 87%). ConclusionEven after PCV10 or PCV13 vaccination, children living in a high-risk setting such as PNG continue to experience high levels of pneumococcal colonization, including carriage of highly antimicrobial-resistant PCV serotypes.The study is registered with ClinicalTrials.gov (CTN NCT01619462).

Pneumococcal vaccine uptake among Medicare Beneficiaries aged ≥65 years following the shared clinical decision-making recommendation for 13-valent pneumococcal conjugate vaccine in 2019

BackgroundIn November 2019, the US Advisory Committee on Immunization Practices recommended shared clinical decision-making (SCDM) for use of 13-valent pneumococcal conjugate vaccine (PCV13) among immunocompetent elderly adults. The impact of SCDM on PCV13 use in this population, immunocompromised persons, and vulnerable subgroups has not been well documented. MethodsUsing Medicare Research Identifiable Files (01/2018 – 09/2020), monthly uptake of pneumococcal vaccine (PCV13, 23-valent pneumococcal polysaccharide vaccine [PPSV23]) was identified among fee-for-service beneficiaries aged ≥ 65 years with Part B coverage and no evidence of prior PCV13. Uptake was stratified by vaccine, risk profile, and demographics. ResultsAmong the > 12 M beneficiaries included each month, PCV13 uptake declined from > 70% of pneumococcal vaccinations before SCDM to < 60% after SCDM (02/2020). Reductions in PCV13 uptake were consistent across vulnerable subgroups as well as immunocompromised persons. ConclusionsPCV13 use decreased among immunocompetent and immunocompromised persons alike, despite continued routine PCV13 recommendation for the latter group.

Cost-Effectiveness of Pneumococcal Vaccination in Adults in Italy: Comparing New Alternatives and Exploring the Role of GMT Ratios in Informing Vaccine Effectiveness.

In Italy, a sequential pneumococcal vaccination with conjugate vaccine (PCV) and polysaccharide vaccine (PPSV23) is recommended for individuals aged ≥ 65 years and those at risk for pneumococcal disease (PD) aged ≥ 6 years. The aim of this study was to assess the cost-effectiveness of the new vaccines, i.e., approved 15-valent and 20-valent PCVs. A published Markov model was adapted to evaluate the lifetime cost-effectiveness of vaccination with PCV15 + PPSV23 versus PCV13 + PPSV23, PCV20 alone, PCV20 + PPSV23, and No Vaccination. Simulated cohorts representing the Italian population, including individuals aged ≥ 65 years, those at risk aged 50-100 years, and those deemed high risk aged 18-100 years were assessed. Outcomes were accrued in terms of incremental PD cases, costs, quality-adjusted life years, life years, and the cost-utility ratio relative to PCV13 + PPSV23. The conservative base case analysis, including vaccine efficacy based on PCV13 data, showed that sequential vaccination with PCV15 or PCV20 in combination with PPSV23 is preferred over sequential vaccination with PCV13 + PPSV23. Especially in the high-risk group, PCV15 + PPSV23 sequential vaccination was dominant over No Vaccination and resulted in an ICUR of €3605 per QALY gained. Including PCV20 + PPSV23 into the comparison resulted in the domination of the PCV15 + PPSV23 and No Vaccination strategies. Additionally, explorative analysis, including the geometric mean titer (GMT) informed vaccine effectiveness (VE) was performed. In the low-risk and high-risk groups, the results of the GMT scenarios showed PCV15 + PPSV23 to be dominant over the other sequential vaccines. These findings suggest that if real-world studies would confirm a difference in vaccine effectiveness of PCV15 and PCV20 versus PCV13 based on GMT ratios, PCV15 + PPSV23 could prove a highly immunogenic and effective vaccination regime for the Italian adult population.

Serotype replacement and an increase in non-encapsulated isolates among community-acquired infections of Streptococcus pneumoniae during post-vaccine era in Japan

ObjectivesIt is feared that the serotype replacement of Streptococcus pneumoniae occurred by the introduction of pneumococcal vaccines as periodical inoculation leads to reduced efficacy of the approved vaccines and altered antimicrobial susceptibility. MethodsWe determined serotypes of 351 S. pneumoniae isolates collected at a commercial clinical laboratory in Hokkaido prefecture, Japan, from December 2018 to February 2019 by using the polymerase chain reaction procedure of the US Centers for Disease Control and Prevention. Antimicrobial susceptibility and resistance gene profiles were also examined. ResultsVaccine coverage rates were 7.9% for 13-valent conjugate vaccine, and 32.5% for 23-valent polysaccharide vaccine, respectively. Non-typable strains were 19.7%. cpsA-positive isolates (group I), and null capsule clade (NCC)1, NCC2 and NCC3 (group II) comprised 31.3%, 28.4%, 32.8%, and 7.5% of the 69 non-typable strains, respectively. No penicillin-resistant/intermediate isolates were found; however, serotypes 35B and 15A/F showed low susceptibility to β-lactams. Only five strains (1.4%) were levofloxacin-resistant, and all were from the older persons, and three strains were serotype 35B. ConclusionThe progression of serotype replacement in non-invasive pneumococcal infections has occurred during the post-vaccine era in Japan, and non-encapsulated isolates, such as NCC, have increased. Antimicrobial susceptibility is not worsened.

Immunogenicity and safety of revaccination of 23-valent pneumococcal polysaccharide vaccine in people aged 60 years and above

Objective: To evaluate the immunogenicity and safety of revaccination of 23-valent pneumococcal polysaccharide vaccine (PPV23) in elderly people aged ≥60 years. Methods: The elderly aged ≥60 years with 1 dose of PPV23 vaccination were selected as revaccination group and those without history of pneumococcal vaccine immunization were selected as the first vaccination group. One dose of PPV23 was administered to both groups, and the first blood samples were collected before vaccination while the second blood samples were collected on day 28-40 after vaccination. ELISA was used to detect the concentrations of anti-specific serotype Streptococcus pneumoniae podocyte polysaccharide immunoglobulin G, and the safety of the vaccination was evaluated after 30 days. Results: The geometric mean concentration (GMC) of antibody to 23 serotypes before the vaccination (0.73-13.73 μg/ml) was higher in revaccination group than in the first vaccination group (0.39-7.53 μg/ml), the GMC after the vaccination (1.42-31.65 μg/ml) was higher than that before the vaccination (0.73-13.73 μg/ml) in the revaccination group, and the GMC after the vaccination (1.62-43.76 μg/ml) was higher than that before the vaccination (0.39-7.53 μg/ml) in the first vaccination group; the geometric mean growth multiple in revaccination group (2.16-3.60) was lower than that in the first vaccination group (3.86-16.13); The mean 2-fold antibody growth rate was lower in revaccination group (53.68%, 95%CI: 52.30%-55.06%) than in the first vaccination group (93.16%, 95%CI: 92.18%- 94.15%), all differences were significant (P<0.001). After the vaccination, 13 serotypes of GMC were higher in the first vaccination group than in revaccination group (P<0.001), the differences were not significant for 10 serotypes of GMC (P>0.05). The incidence of local adverse reaction was 19.20% and 13.27% in revaccination group and the first vaccination group, respectively (P=0.174). Conclusions: The antibody level in ≥60 years people who received one dose of PPV23 after a 5-year interval was still higher than that in unvaccinated people. The antibody level decreased after 5 years of the first vaccination, and the antibody level could be rapidly increased by one more dose vaccination, but the overall immune response was lower than that of the first vaccination; revaccination with PPV23 has a good safety.

Safety and immunogenicity of quadrivalent meningococcal polysaccharide vaccine (MPV ACYW135) compared with quadrivalent meningococcal conjugate vaccine (Menactra®) in Malian children

ABSTRACT Affordable, polyvalent meningococcal vaccines are needed for use in emergency reactive immunization campaigns. A phase IV randomized, observer-blind, controlled study compared the safety and immunogenicity of a quadrivalent meningococcal polysaccharide vaccine (MPV-4, MPV ACYW135) and quadrivalent meningococcal ACWY conjugate vaccine (MCV-4, Menactra®). Healthy, 2- to 10-year-old children in Bamako, Mali, were randomized 1:1 to receive one dose of MPV-4 or MCV-4. Safety outcomes were evaluated for 6 months post-immunization. Immunogenicity for all serogroups was assessed for non-inferiority between MPV-4 and MCV-4 30 days post immunization by serum bactericidal antibody assay using baby rabbit complement (rSBA). From December 2020 to July 2021, 260 healthy subjects were consented and randomized. At Day 30 post-immunization, the proportions of subjects with rSBA titers ≥ 128 for all serogroups in the MPV-4 group were non-inferior to those in MCV-4 group. The proportions of subjects with rSBA ≥ 4-fold increase and rSBA titers ≥ 8 for all serogroups were similar among vaccine groups (P > .05). Geometric Mean Titers and Geometric Mean Fold Increases for all serogroups in both vaccine groups were similar (P > .05). Few local and systemic post-immunization reactions of similar severity and duration were observed within 7 days and were similar in both groups (P > .05). All resolved without sequelae. Unsolicited adverse events were similar in both groups regarding relationship to study vaccine, severity and duration. No serious adverse events were reported during the study period. MPV ACYW135 showed a non-inferior immunogenicity profile and a comparable reactogenicity profile to MCV-4 in Malian children aged 2–10 years. Clinical Trial Registration: NCT04450498.

Immunogenicity of the 13-Valent Pneumococcal Conjugated Vaccine Followed by the 23-Valent Polysaccharide Vaccine in Chronic Lymphocytic Leukemia.

Patients with Chronic Lymphocytic Leukemia (CLL) have a 29- to 36-fold increased risk of invasive pneumococcal disease (IPD) compared to healthy adults. Therefore, most guidelines recommend vaccination with the 13-valent pneumococcal conjugated vaccine (PCV13) followed 2 months later by the 23-valent polysaccharide vaccine (PPSV23). Because both CLL as well as immunosuppressive treatment have been identified as major determinants of immunogenicity, we aimed to assess the vaccination schedule in untreated and treated CLL patients. We quantified pneumococcal IgG concentrations against five serotypes shared across both vaccines, and against four serotypes unique to PPSV23, before and eight weeks after vaccination. In this retrospective cohort study, we included 143 CLL patients, either treated (n = 38) or naive to treatment (n = 105). While antibody concentrations increased significantly after vaccination, the overall serologic response was low (10.5%), defined as a ≥4-fold antibody increase against ≥70% of the measured serotypes, and significantly influenced by treatment status and prior lymphocyte number. The serologic protection rate, defined as an antibody concentration of ≥1.3 µg/mL for ≥70% of serotypes, was 13% in untreated and 3% in treated CLL patients. Future research should focus on vaccine regimens with a higher immunogenic potential, such as multi-dose schedules with higher-valent T cell dependent conjugated vaccines.

Pneumococcal Vaccine in Adults with Bronchopulmonary Pathology: from Prevention to Treatment

Relevance. Community-acquired pneumonia and chronic obstructive pulmonary disease (COPD) remain a serious public health problem in all respects today.Aims. To summarize the studies of domestic authors on the study of the effect of pneumococcal polysaccharide vaccine on various parts of the immune system and their relationship with the clinical course of the disease in patients with COPD and community-acquired pneumonia. We also consider it necessary to discuss the possible mechanisms of therapeutic effects after the introduction of a monovaccine against S. pneumoniae, as well as when it is combined with vaccines against Haemophilus influenzae type b infection, and the effectiveness of various vaccination regimens, including complex ones.Conclusions. Convincing arguments are presented proving that the introduction of vaccines against respiratory infections can have not only a reventive value, but also a therapeutic effect, accompanied by a transient restoration of the immune system parameters, as well as a reduction in the contamination or elimination of S. pneumoniae in patients with chronic pathology of the bronchopulmonary system.

Regional Features of the Serotype Composition of Streptococcus pneumoniae isolated from Bacterial Carriers of Preschool Age in the Republic of Tatarstan

Relevance. Vaccination of the child population against pneumococcal infection (PI) has been carried out in the Republic of Tatarstan according to the national calendar of preventive vaccinations since 2014. The vaccination scheme includes vaccination with PCV-13 conjugated pneumococcal vaccine.Aim. Study of the the frequency of bacterial transmission and the serotype landscape of S. pneumoniae isolated from healthy children- bacterial carriers of preschool age in the Republic of Tatarstan (RT).Materials and methods. During the period from 2016 to 2022, 1,426 children from Kazan and the districts of the Republic of Tatarstan were examined. Examination of nasopharyngeal smears was carried out by the classical bacteriological method. Serotyping was performed using molecular genetic methods (PCR).Results. The detection rate of S. pneumoniae among healthy preschool children varied in different years from 29.5 to 63%, averaging 38.5%. In urban children, the incidence of pneumococcal transmission was significantly higher than in rural children (p&lt;0.01). Also, when analyzing the serotype landscape, mixed colonization by several serotypes was observed. As of January 1, 2021, the immune layer to the pathogen PI among preschool children was 81.7%. Monitoring of the serotype landscape of S.pneumoniae strains circulating in the RT showed the dominance of vaccine serotypes (67.2%), of which 44.4% are PCV13 serotypes. The proportion of non–vaccinated serotypes is 26%, untyped - 6.8%. Unvaccinated serotypes 35B (21.3%) and 23A (13.6%) dominated in vaccinated children, as well as serotypes not included in the PKV-13 vaccine cocktail, but included in the PPSV-23 polysaccharide vaccine not used for vaccination of children, namely 11AD (15.3%) 9LN (9.6%). In unvaccinated children, on the contrary, vaccine serotypes included in PCV-13 prevailed: 6ABCD (17.3%), 19F (20.9%), and unvaccinated serotypes 11AD, 9LN, 35B, 23A were detected with lower frequency 11,8%, 10,0%, 4,2%, 7,3% accordingly.Conclusion. Data on the regional features of the pneumococcal serotype landscape can be the basis for expanding the vaccine cocktail due to the dominant serotypes: 9LN,11 AD, 35B, 23A.

Safety, tolerability, and immunogenicity of a 21-valent pneumococcal conjugate vaccine, V116, in Japanese healthy adults: A Phase I study

ABSTRACT V116 is an investigational 21-valent pneumococcal conjugate vaccine (PCV) to address the burden of residual adult pneumococcal disease after the introduction of pediatric PCVs into national immunization programs (NIPs) and includes serotypes highly prevalent in adult invasive pneumococcal disease (IPD). This Phase I study assessed the safety, tolerability, and immunogenicity of V116 in Japanese adults. Participants ≥20 years of age were randomized to receive a single dose of V116 or 23-valent pneumococcal polysaccharide vaccine (PPSV23) at day 1. Outcomes were solicited injection-site and systemic adverse events (AEs) from day 1 to day 5, vaccine-related serious AEs from day 1 through day 30, and serotype-specific opsonophagocytic antibody (OPA) titers and immunoglobulin G (IgG) concentrations at day 30. Overall, 102 participants were randomized 1:1 to each group. Comparable proportions vaccinated with V116 and PPSV23 experienced ≥1 solicited injection-site AE and ≥1 solicited systemic AE. The most common injection-site AEs were injection-site pain (V116: 54.9%; PPSV23: 66.7%) and swelling (V116 and PPSV23: 13.7%), and the most common systemic AEs were myalgia (V116: 17.6%; PPSV23: 19.6%) and fatigue (V116: 13.7%; PPSV23: 9.8%). Solicited AEs were mostly mild and of ≤3 days duration. No vaccine-related serious AEs or deaths were reported. The OPA and IgG findings showed that the immunogenicity of V116 and PPSV23 were comparable for the 12 common serotypes and V116 was more immunogenic for the nine unique serotypes compared with PPSV23. V116 was well tolerated, with a safety profile similar to PPSV23, and induced functional antibodies against all 21 serotypes.

A cost-effectiveness analysis of the 13-valent pneumococcal conjugated vaccine and the 23-valent pneumococcal polysaccharide vaccine among Thai older adult.

This study aims to assess the economic impact of introducing the 13-valent pneumococcal conjugate vaccine (PCV13) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) to Thai older adult aged ≥ 65 years who are healthy or with chronic health conditions and immunocompromised conditions from a societal perspective in order to introduce the vaccine to Thailand's National Immunization Program for the older adult. A Markov model was adopted to simulate the natural history and economic outcomes of invasive pneumococcal diseases using updated published sources and Thai databases. We reported analyses as incremental cost-effectiveness ratios (ICER) in USD per quality-adjusted life year (QALY) gained. In addition, sensitivity analyses and budget impact analyses were conducted. The base-case analysis of all interventions (no vaccinations [current standard of care in Thailand], PPSV23, and PCV13) showed that PPSV23 was extendedly dominated by PCV13. Among healthy individuals or those with chronic health conditions, ICER for PCV13 was 233.63 USD/QALY; meanwhile, among individuals with immunocompromised conditions, ICER for PCV13 was 627.24 USD/QALY. PCV13 are economical vaccine for all older adult Thai individuals when compared to all interventions. In the context of Thailand, PCV13 is recommended as the best buy and should be primarily prioritized when both costs and benefits are considered. Also, this model will be beneficial to the two-next generation pneumococcal vaccines implementation in Thailand.

Non-protective immunity after standard pneumococcal vaccination series identified as a potential contributing risk factor for refractory otolaryngologic conditions in children.

To examine the relationship between conferred immunity after standard pneumococcal series and refractory otolaryngologic infections in pediatric patients using post-vaccination antibody titers, and to identify contributory underlying conditions revealed when vaccination/re-vaccination fails to confer protective immunity. IRB-reviewed and "exempt" retrospective case series with chart review using the Epic® Electronic Medical Record system from 2013 to 2021. Dedicated tertiary referral children's hospital. Pneumococcal antibody titer results were assessed for children ages 0 to 21 years and: (1) at least 1 of 7 otolaryngologic disease diagnoses and (2) having received the 4-dose schedule of pneumococcal conjugate vaccine (PCV 7 or 13). A total of 241 subjects met inclusion criteria with 356 laboratory tests. Recurrent acute otitis media, chronic rhinitis, and chronic otitis media with effusion were the 3 most frequent diagnoses. At presentation, only 27.0% of subjects had titers conferring immunity from their prior vaccinations with PCV. About 85 subjects had been subsequently revaccinated with Pneumococcal Polysaccharide Vaccine (PPSV), and antibody responses conferring immunity reached 91.8%. Seven subjects never developed adequate responses; 5 of these had recurrent acute otitis media as the primary otolaryngologic diagnosis. Secondary "revealed" diagnoses included Juvenile Rheumatoid Arthritis (n = 1), unresolved specific antibody deficiency (n = 2), and Hypogammaglobulinemia (n = 1). In pediatric patients with recurrent infectious otolaryngologic disease refractory to traditional medical and surgical therapy, inadequate responses to pneumococcal vaccination may be revealed. This correlation represents a potential pathway for diagnosis and therapy.

Adherence to vaccination guidelines of patients with complete splenectomy in Norway, 2008–2020

The spleen is responsible for blood filtration and mounting an immune response against pathogens. In some people the spleen must be surgically removed because of traumatic events or oncological and hematological conditions. These patients are at higher risk of developing diseases caused by encapsulated bacteria throughout their lives. Thus, immunisations are advised for splenectomised persons to prevent infection caused by Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b (Hib). This study assessed vaccination coverage (VC) among Norwegian patients with surgical asplenia. Using the Nomesco Classification of Surgical Procedures codes, patient information (age, sex, date of initial diagnosis and date of surgery) was acquired from the Norwegian Patient Registry. The National Immunization Register provided information on vaccination status and data of any subsequent invasive bacterial infections were obtained from the Norwegian Surveillance System for Communicable Diseases. From the total population of Norway, 3155 patients who had undergone complete splenectomy were identified. Of these, 914 (29.0%) had received at least one dose of pneumococcal conjugate vaccine (PCV), 1324 (42.0%) at least one dose of pneumococcal polysaccharide vaccine and 589 (18.7%) had received both. Only 4.2% of the patients had received two doses of a meningococcal ACWY conjugate vaccine, while 8.0% of 1467 patients splenectomised after 2014 had received at least two doses of a serogroup B meningococcal vaccine. The VC for Hib was 18.7%. Nearly all splenectomised children under the age of 10 were vaccinated with Hib and PCV as these vaccines are included in the childhood immunisation program. For all vaccines, VC decreased with age. Twenty-nine invasive bacterial infections were registered post-splenectomy in 25 patients. Vaccination according to national recommendations could have prevented at least 8 (28%) of these infections. Our study showed that efforts are required to increase VC of splenectomised individuals in Norway.

Marketing Two Immunization Services at a Regional Supermarket Chain Pharmacy.

Background: Personal selling of immunization services includes starting a dialogue with patients, utilizing effective questioning and listening skills to identify their vaccination needs, and recommending appropriate vaccines accordingly. The study objectives were (1) to integrate personal selling into the dispensing workflow to promote pneumococcal polysaccharide vaccine (PPSV23), and (2) to evaluate the impact of personal selling and automated telephone calls to promote herpes zoster vaccine (ZVL). Methods: For the first study objective, a pilot project was conducted at one out of 19 affiliated supermarket pharmacies. Dispensing records were used to target patients with diabetes mellitus for PPSV23, and personal selling was implemented over a 3-month period. For the second study objective, a full study was conducted among the nineteen pharmacies, with five in the study group and 14 in the control group. Personal selling was implemented over a 9-month period, and automated telephone calls were placed and tracked over a 6-week period. Mann-Whitney U tests were used to compare vaccine delivery rates between the study and control groups. Results: In the pilot project, 47 patients needed PPSV23, but none received it from the pharmacy. In the full study, 900 ZVL vaccines were given, with 459 given for 15.5% of the eligible patients in the study group. During the time when 2087 automated telephone calls were placed and tracked, 85 vaccines were given across all pharmacies, with 48 given for 1.6% of the eligible patients in the study group. During both the 9-month and 6-week periods, the mean ranks of vaccine delivery rates in the study group were higher than the control group (p < 0.05). Conclusions: The pilot project incorporated personal selling into the dispensing workflow and, although no vaccines were given, provided valuable lessons. The full study demonstrated that personal selling alone and personal selling combined with automated telephone calls were associated with higher vaccine delivery rates.

Predictors of serological non-response to the 13-valent pneumococcal conjugate vaccine followed by the 23-valent polysaccharide vaccine among adults living with HIV

BackgroundPeople living with HIV (PLWH) have higher incidence of pneumococcal disease compared to people without HIV. Immunization with pneumococcal vaccines is recommended, but serological non-response to pneumococcal vaccination is common for largely unknown reasons. MethodsPLWH on antiretroviral treatment and no prior pneumococcal vaccination received the 13-valent pneumococcal conjugate vaccine (PCV13) followed 60 days later by the 23-valent polysaccharide vaccine (PPV23). Serological response was evaluated 30 days post-PPV23 by antibodies against 12 serotypes covered by both PCV13 and PPV23. Seroprotection was defined as a ≥2-fold rise to a level above 1.3 µg/ml in geometric mean concentration (GMC) across all serotypes. Associations with non-responsiveness were evaluated by logistic regression. ResultsFifty-two virologically suppressed PLWH (median age of 50 years (IQR 44–55) and median CD4 count of 634 cells/mm3 (IQR 507–792)) were included. Forty-six percent (95 % CI 32–61, n = 24) achieved seroprotection. Serotypes 14, 18C and 19F had the highest, and serotypes 3, 4 and 6B the lowest GMCs. Pre-vaccination GMC levels less than 100 ng/ml were associated with increased odds of non-responsiveness compared to levels above 100 ng/ml (adjusted OR 8.7, 95 % CI 1.2–63.6, p = 0.0438). ConclusionLess than half of our study population achieved anti-pneumococcal seroprotective levels following PCV13 and PPV23 immunization. Low pre-vaccination GMC levels were associated with non-response. Further research is required to optimize vaccination strategies that achieve higher seroprotection in this high-risk group.

Pneumococcal vaccination coverage and adherence to recommended dosing schedules in adults: a repeated cross-sectional study of the INTEGO morbidity registry

BackgroundSince 2014, Belgium’s Superior Health Council has recommended pneumococcal vaccination for adults aged 19–85 years at increased risk for pneumococcal diseases with a specific vaccine administration sequence and timing. Currently, Belgium has no publicly funded adult pneumococcal vaccination program. This study investigated the seasonal pneumococcal vaccination trends, evolution of vaccination coverage and adherence to the 2014 recommendations.MethodsINTEGO is a general practice morbidity registry in Flanders (Belgium) that represents 102 general practice centres and comprised over 300.000 patients in 2021. A repeated cross-sectional study was performed for the period between 2017 and 2021. Using adjusted odds ratios computed via multiple logistic regression, the association between an individual’s characteristics (gender, age, comorbidities, influenza vaccination status and socioeconomic status) and schedule-adherent pneumococcal vaccination status was assessed.ResultsPneumococcal vaccination coincided with seasonal flu vaccination. The vaccination coverage in the population at risk decreased from 21% in 2017 to 18.2% in 2018 and then started to increase to 23.6% in 2021. Coverage in 2021 was highest for high-risk adults (33.8%) followed by 50- to 85-year-olds with comorbidities (25.5%) and healthy 65- to 85-year-olds (18.7%). In 2021, 56.3% of the high-risk adults, 74.6% of the 50+ with comorbidities persons, and 74% of the 65+ healthy persons had an adherent vaccination schedule. Persons with a lower socioeconomic status had an adjusted odds ratio of 0.92 (95% Confidence Interval (CI) 0.87–0.97) for primary vaccination, 0.67 (95% CI 0.60–0.75) for adherence to the recommended second vaccination if the 13-valent pneumococcal conjugate vaccine was administered first and 0.86 (95% CI 0.76–0.97) if the 23-valent pneumococcal polysaccharide vaccine was administered first.ConclusionPneumococcal vaccine coverage is slowly increasing in Flanders, displaying seasonal peaks in sync with influenza vaccination campaigns. However, with less than one-fourth of the target population vaccinated, less than 60% high-risk and approximately 74% of 50 + with comorbidities and 65+ healthy persons with an adherent schedule, there is still much room for improvement. Furthermore, adults with poor socioeconomic status had lower odds of primary vaccination and schedule adherence, demonstrating the need for a publicly funded program in Belgium to ensure equitable access.

Pneumococcal vaccination coverage at the initiation of chronic dialysis, and its association with mortality during the first year.

Pneumococcal immunization is recommended in dialysis patients. We aimed to estimate pneumococcal vaccination coverage among patients who initiate dialysis in France, and its association with mortality. Data were extracted from two prospective national databases, merged using a deterministic linkage method: renal epidemiology and information network (REIN) registry, which includes all patients on dialysis and kidney transplants recipients in France, and the national health insurance information system (SNIIRAM) which collects individual data on health expenditure reimbursement, including vaccines. We enrolled all patients who initiated chronic dialysis in 2015. Data on health status at dialysis initiation, dialysis modalities, and pneumococcal vaccine prescribed from 2years before to 1year after dialysis start were collected. Univariate and multivariate Cox proportional hazard models were used to assess one-year all-cause mortality. Among the 8,294 incident patients included, 1,849 (22.3%) received at least one pneumococcal vaccine before (n=542, 6.5%), or after (n=1,307, 15.8%) dialysis start, as follows: 13-valent pneumococcal conjugated vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23), n=938 (50.7%); only PPSV23, n=650 (35.1%); or only PCV13, n=261 (14.1%). Vaccinated patients were younger (mean, 66.5±14.8years vs. 69.0±14.9years, P≤0.001), more likely to suffer from glomerulonephritis (17.0% vs. 11.0%, P≤0.001), and less likely to start dialysis in emergency (27.2% vs. 31.1%, P=0.001). On multivariate analysis, patients who received PCV13 and PPSV23, or only PCV13 were less likely to die (respectively, HR=0.37; 95%CI 0.28-0.51, and HR=0.35; 95%CI 0.19-0.65). Pneumococcal immunization with PCV13 followed by PPSV23, or with PCV13 alone, but not with PPSV23 alone, is independently associated with decreased one year-mortality in patients who start dialysis.

HTA49 Cost-Utility Analysis of Pneumococcal Vaccines for Older Adults Available in El Salvador

In El Salvador, the 13-valent pneumococcal conjugate vaccine (PCV13) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) are available to prevent invasive pneumococcal disease (IPD) such as meningitis, bacteremia, as well as community-acquired pneumococcal pneumonia (CAP) caused by serotypes contained in these vaccines. This analysis estimated the clinical and economic values of PCV13 and PPSV23 from the public healthcare perspective.