Impact of COVID-19 on vaccine confidence and uptake: A systematic literature review.

During the coronavirus disease 2019 (COVID-19) pandemic, scheduled vaccinations were postponed, mass vaccination programmes were suspended and opportunities for healthcare workers to administer vaccines ad hoc decreased. The aims of this systematic literature review were to determine the impact of the COVID-19 pandemic on vaccine confidence, intent and uptake in preexisting routine childhood or adult vaccination programmes, and to identify factors associated with changes in acceptance, intent and uptake of preexisting vaccines. Medline and Embase were searched for studies in Australia, Brazil, Canada, China, Japan, the USA, and European countries, published between 1 January 2021 and 4 August 2022. A complementary gray literature search was conducted between 11 and 13 October 2022, and supplemented with additional gray research in October 2023. In total, 54 citations were included in the review. Study design and geography were heterogeneous. The number of adults who received or intended to receive an influenza or pneumococcal vaccine was higher during the pandemic than in previous seasons (n = 28 studies). In addition, increased acceptance of adult vaccinations was observed during 2020-21 compared with 2019-20 (n = 12 studies). The rates of childhood vaccinations decreased during the COVID-19 pandemic across several countries (n = 11 studies). Factors associated with changes in intention to receive a vaccination, or uptake of influenza vaccine, included previous vaccination, older age, higher perceived risk of contracting COVID-19, anxiety regarding the pandemic and fear of contracting COVID-19. Acceptance and uptake of influenza and pneumococcal vaccines generally increased after onset of the COVID-19 pandemic.

Preliminary Evaluation of the Safety and Immunogenicity of a Novel Protein-Based Pneumococcal Vaccine in Healthy Adults Aged 18-49: A Phase Ia Randomized, Double Blind, Placebo-Controlled Clinical Study.

Background: Protein-based pneumococcal vaccines (PBPVs) may offer expanded protection against Streptococcus pneumoniae and tackle the antimicrobial resistance crisis in pneumococcal infections. This study examined the safety and immunogenicity in healthy adults vaccinated with three doses of a protein-based pneumococcal vaccine containing pneumococcal surface protein A (PspA) (PRX1, P3296 and P5668) and in combination with a recombinant detoxified pneumolysin protein (PlyLD). Methods: This phase Ia randomized, double blind, placebo-controlled clinical study enrolled healthy adults aged 18-49 years. The participants were randomized into experimental (low-dose, medium-dose, high-dose) and placebo groups in a ratio of 3:1. Three doses of investigational vaccine were given to the participants with an interval of two months. Safety endpoints included the occurrence of total adverse reactions, solicited local and systemic adverse reactions, unsolicited adverse reactions, serious adverse events (SAEs), and several laboratory parameters. Immunogenicity endpoints included geometric mean titers (GMT) of anti-PspA (PRX1, P3296 and P5668) and anti-PlyLD antibodies level as determined by ELISA, seropositivity rates of PspA and PlyLD antibodies (>4-fold increase) and neutralization activity of anti-Ply antibody in serum. Results: A total of 118 participants completed the study of three doses. The candidate PBPV was safe and well-tolerated in all experimental groups. No vaccine-related SAEs were observed in this study. Most solicited adverse reactions were mild and transient. The most frequently reported solicited adverse reactions in the medium- and high-dose groups was pain at the injection site, while in the low-dose group it was elevated blood pressure. The immunogenicity data showed a sharp increase in the GMT level of anti-PspA-RX1, anti-PspA-3296, anti-PspA-5668, and anti-PlyLD antibodies in serum. The results also showed that the elicited antibodies were dosage-dependent. The high-dose group showed a higher immune response against PspA-RX1, PspA-3296, PspA-5668, and PlyLD antigens. However, repeat vaccination did not increase the level of anti-PspA antibodies but the level of anti-PlyLD antibody. High seropositivity rates were also observed for anti-PspA-RX1, anti-PspA-3296, anti-PspA-5668, and anti-PlyLD antibodies. In addition, a significant difference in the GMT levels of anti-Ply antibody between the high-, medium-, and low-dose groups post each vaccination were indicated by neutralization activity tests. Conclusions: The PBPV showed a safe and immunogenic profile in this clinical trial. Taking into consideration both safety and immunogenicity data, we propose a single dose of 50 µg (medium dose) of PBPV as the optimum approach in providing expanded protection against Streptococcus pneumoniae.

Social Media Promotion of a Telehealth-based Vaccine Delivery System at the Outpatient Department: a Quasi-Experimental Study.

Background and Objective: COVID-19 pandemic gave rise to an increase in demand for pneumococcal and influenza vaccines. Several approaches to improve vaccination rates among different populations were investigated to address this need. Social media may be used as a platform to promote and improve vaccination rates. The study aimed to determine the effect of social media promotion, on the number of patients requesting vaccination in a government tertiary hospital. Methods: The study was conducted using a quasi-experimental design. A telehealth-based vaccination delivery system was established. The need for vaccination against flu and pneumonia was then promoted on a social media platform during the first month of the study. Posters on the risk of not being vaccinated and safety profile of vaccines were added on the second month. The number of requests for vaccination for each month was compared. Social media metrics of the two months of the study were likewise described. Results: A total of 23 requests for vaccination were recorded, 11 on the first month and 12 on the second month. When a boost in advertising for the posts was implemented, twice as many requests were made during the third week of the second month as compared to the previous month (5 vs 10). Social media promotion with poster showed higher average in reach, engagement and comments per week than without poster. The mean differences among the social media metrics, however, were not statistically significant. Conclusion: Promotion with posters resulted in a slight increase in number of vaccination requests. Further increase in requests may require a more refined social media promotional strategy.

Regional differences in pediatric pneumococcal vaccine schedules for Indigenous children in Canada: an environmental scan.

BACKGROUND: Streptococcus pneumoniae bacteria causes substantial morbidity and mortality worldwide, especially in children under 5 years of age. Prevention of these outcomes by pneumococcal conjugate vaccines (PCV) is an important public health initiative, supported by publicly funded vaccination programs in Canada. While the National Advisory Committee on Immunization (NACI) provides national recommendations for vaccination schedules, decisions on vaccination program delivery are made regionally, creating potential for variability across the country. In addition, defining the groups that are most at risk has become a complex endeavor for provinces and territories in Canada, specifically considering Indigenous children. METHODS: In this environmental scan, we reviewed policy documents, provincial/territorial and international PCV schedules, and scientific literature, and consulted with vaccination program stakeholders and experts from across the country, in order to understand the evolution of PCV vaccination guidelines and policies in Canada and identify whether and how the needs of Indigenous children are addressed. RESULTS: As of March 2023, most regions do not specify particular vaccination requirements for Indigenous children; however, three provinces identify Indigenous children as "high risk" and use varying language to recommend a four dose, rather than the routine three dose, schedule. Our results also draw attention to evidence gaps supporting a differing practice for Indigenous populations. CONCLUSIONS: Future PCV program innovation requires inclusive and clear policies as well as definitive evidence-based policies and practices in order to improve equitable population health.

Protective Effects from Prior Pneumococcal Vaccination in Patients with Chronic Airway Diseases during Hospitalization for Influenza-A Territory-Wide Study.

Influenza is an important respiratory viral pathogen in adults, with secondary bacterial pneumonia being a common complication. While pneumococcal vaccines can prevent pneumococcal pneumonia and invasive pneumococcal disease, whether they can also prevent the severe in-hospital outcomes among patients hospitalized for influenza has not been examined. A territory-wide retrospective study was conducted in Hong Kong, which included all adult patients having chronic airway diseases (asthma, bronchiectasis, and chronic obstructive pulmonary disease) hospitalized for influenza and who had received seasonal influenza vaccine. The occurrence of secondary bacterial pneumonia, mortality, and other severe in-hospital outcomes were compared among subjects with or without pneumococcal vaccination. There was a total of 3066 eligible patients who were hospitalized for influenza in public hospitals in Hong Kong from 1 January 2016 to 30 June 2023. Completed pneumococcal vaccination with PSV23/PCV13 conferred protection against secondary bacterial pneumonia, all-cause mortality, and respiratory cause of mortality with adjusted odds ratios of 0.74 (95% CI = 0.57-0.95, p = 0.019), 0.12 (95% CI = 0.03-0.53, p = 0.005), and 0.04 (95% CI = 0.00-0.527, p = 0.0038), respectively.

Pediatric Pneumococcal Conjugate Vaccine and Dosing Schedule Perceptions Among Health Care Providers and Caregivers in Germany, France, Spain, and Greece.

INTRODUCTION: Most European infant national immunization programs (NIPs) recommend pneumococcal conjugate vaccines (PCVs), which currently cover 10-15 serotypes administered in a three-dose schedule (two primary plus one booster). Recently, a PCV covering 20 serotypes that is administered in a four-dose schedule (three primary plus one booster) was licensed. METHODS: An online survey was administered to collect data from health care providers (HCPs) and caregivers of children aged 0-5 (including expectant mothers) in four European countries (Germany, France, Spain, and Greece). All caregiver respondents had a shared or full responsibility to make health decisions for their child. Data on opinions, perceptions, and openness to a change in childhood vaccination dosing schedules were collected, along with demographic information for HCPs as well as caregivers. RESULTS: A total of 601 HCPs and 1954 caregivers were recruited across the four countries. Nearly all HCPs (93%) agreed that broader serotype coverage against pneumococcal disease for children is a significant unmet need, and 92% had a "sense of urgency" to vaccinate children. Both HCPs and caregivers were supportive of an additional PCV dose and doctor visit, assuming it provided at least 20% more serotype coverage than what is currently available. Caregivers strongly agreed on the importance of full vaccination for pneumococcal disease, even if an extra dose and visit to the doctor was required. CONCLUSIONS: HCPs and caregivers were virtually unanimous in their support for a PCV with broader serotype coverage and showed a subsequent willingness to include an extra infant dose/visit. These results can help guide broader discussions regarding public health policy and vaccine administration in the context of important efforts to reduce the global disease burden associated with pneumococcal disease.

Assessing the Vaccination Status and Barriers to Influenza, Pneumococcal, and COVID-19 Vaccination Among Moroccan Patients With Chronic Inflammatory Rheumatic Disease.

OBJECTIVE: To evaluate the vaccination coverage of patients with chronic inflammatory rheumatic disease (CIRD) against influenza, pneumococcus, and COVID-19 and to determine, per the patients' point of view, the possible factors related to vaccination hesitation and/or refusal. METHODS: A cross-sectional study carried out by the vaccination working group of the Moroccan Society of Rheumatology, including patients with CIRD in Morocco. Information about vaccination coverage and reasons for non-vaccination against influenza, pneumococcal infection, and COVID-19 was collected. RESULTS: This survey included 230 patients (mean age of 46.9 +/-13.89 years; 68.7% females) affected by CIRD (rheumatoid arthritis 53%, spondyloarthritis 39.6%, psoriatic arthritis 7%). The study shows a significant lack of influenza and pneumococcal vaccination in CIRD patients, with vaccination coverage against influenza, pneumococcal infection, and COVID-19 at 2.2%, 0.4%, and 80.9%, respectively. The main reason for non-vaccination against influenza and pneumococcus was related to the absence of recommendations by their doctors (77%, 87%, p = 0.04). Additionally, the primary reason for non-vaccination against COVID-19 was the fear of the vaccine's side effects (51%, p = 0.0001), mainly a flare-up of CIRD (44%, p = 0.001). CONCLUSION: This survey shows a lack of influenza, pneumococcal, and COVID-19 vaccination in CIRD patients. The principal actions to improve vaccination should aim to educate patients and encourage rheumatologists to vaccinate their patients.

Pneumococcal vaccine uptake in patients with inflammatory arthritis: a single centre cohort study.

INTRODUCTION: Current guidelines recommend pneumococcal vaccination in individuals who are over the age of 65 or are immunosuppressed due to a disease or treatment. The objective of this study was to assess vaccine uptake rates in people with inflammatory arthritis for the pneumococcal, influenza and Covid-19 vaccines and factors determining uptake. METHODS: We conducted a retrospective single centre cohort study in the UK of individuals with rheumatoid arthritis, psoriatic arthritis and axial spondylarthritis between October and December 2023. Data were collected for age, gender, co-morbidities, immunosuppressive therapies, and dates of vaccines. Logistic regression was used to evaluate predictors of vaccine uptake, with adjustments for demographic and clinical factors. RESULTS: 906 individuals were identified. 46% were receiving treatment with csDMARD, 26% on biologic monotherapy, and 23% were on both biologic and csDMARDs. 316 individuals (35%) received a pneumococcal vaccine, lower than uptake for influenza (63%) and Covid-19 (87%) vaccines. Predictors of pneumococcal vaccine uptake included age, with older patients more likely to be vaccinated (odds ratio [OR] for age ≥ 65 years: 1.67, 95% CI 1.21-2.29). Those on biological therapy demonstrated higher likelihood of vaccination (OR for biologic therapy: 1.81, 95% CI 1.33-2.47). Additional Joint committee for immunisation and vaccination (JCVI) Green Book indicators also positively influenced vaccine uptake (OR: 1.67, 95% CI 1.19-2.33). CONCLUSION: Pneumococcal vaccine uptake in inflammatory rheumatic diseases is low, especially in younger patients and those not on biological therapy. The study highlights the need for a focused approach, distinct from strategies for other vaccines, to address this public health challenge.

Uptake among four indicated vaccines by adults aged 65 years and older in Japan, 2023.

Various vaccinations are recommended for older adults; however, unlike childhood immunization programs, there is often no systematic immunization schedule for older adults, and management of the immunization schedule is the responsibility of the individuals. Self-managing immunization status can be challenging and potentially lead to missed vaccinations. This study aimed to describe the statuses and patterns of indicated vaccine uptake among older adults. This descriptive study utilized data from a large-scale nationwide internet survey in Japan (n = 6,828). Participants aged 65 years and older were asked about their immunization status for four vaccines in Japan: coronavirus disease 2019, influenza, pneumococcal, and herpes zoster vaccines. Overall, 6.8 % of the participants received all four vaccines, whereas 9.5 % had not received any of four vaccines. Many participants received one to three types of vaccinations (one type: 24.7 %, two types: 30.8 %, three types: 28.1 %). Attention should be focused on vaccine uptake among older adults.

The effectiveness of revaccination with pneumococcal polysaccharide vaccine for preventing pneumococcal disease in older adults in England: A population-based cohort study.

BACKGROUND: Pneumococcal disease in older adults in the United Kingdom is rising despite immunisation. A key gap in the literature is the clinical effectiveness of revaccination with the pneumococcal polysaccharide vaccine (PPV23). METHODS: A cohort study was performed in England, using electronic medical records in the Clinical Practice Research Datalink. Individuals aged ≥64 years and vaccinated with PPV23 were included. Rates of hospitalised pneumonia (HP) and invasive pneumococcal disease (IPD) were compared between individuals receiving a single PPV23 dose versus those receiving two doses using multi-level Cox proportional hazards models. Propensity score weighting was performed to minimise the effect of confounding covariates across the comparison groups. RESULTS: Between 2006 and 2019, there were 462 505 eligible participants. Of those, 6747 (1·5 %) received revaccination. Two doses compared to one dose was associated with an increased risk of HP (adjusted Hazard Ratio [aHR] 1·95; 95 %CI 1·74-2·20) and IPD (aHR 1·44; 95 %CI 1·41-1·46). In participants aged 64-74 years PPV23 revaccination was associated with more IPD (aHR 2·02; 95 %CI 1·75-2·33) and HP (aHR 1·46; 95 %CI 1·42-1.49). In those aged ≥75 years PPV23 revaccination was associated with more HP (aHR 1·12; 95 %CI 1·08-1·16) with no statistically significant difference detected in risk of IPD (aHR 1·20; 95 %CI 0·94-1·52). CONCLUSIONS: No clear benefit of PPV23 revaccination was measured in older adults in this observational study. The small proportion of revaccinated subjects limits the strength of the conclusions. Further research evaluating the clinical effectiveness of PPV23 revaccination is required.

Adherence to Advisory Committee on Immunization Practices in diabetes mellitus patients in Saudi Arabia: A multicenter retrospective study.

BACKGROUND: Patients with diabetes mellitus (DM) are predisposed to an increased risk of infection signifying the importance of vaccination to protect against its potentially severe complications. The Centers for Disease Control and Prevention/Advisory Committee on Immunization Practices (CDC/ACIP) issued immunization re-commendations to protect this patient population. AIM: To assess the adherence of patients with DM to the CDC/ACIP immunization recommendations in Saudi Arabia and to identify the factors associated with the vaccine adherence rate. METHODS: An observational retrospective study conducted in 2023 was used to collect data on the vaccination records from 13 diabetes care centers in Saudi Arabia with 1000 eligible patients in phase I with data collected through chart review and 709 patients in phase II through online survey. RESULTS: Among participants, 10.01% (n = 71) had never received any vaccine, while 85.89% (n = 609) received at least one dose of the coronavirus disease 2019 (COVID-19) vaccine, and 34.83% (n = 247) had received the annual influenza vaccine. Only 2.96% (n = 21), 2.11% (n = 15), and 1.12% (n = 8) received herpes zoster, tetanus, diphtheria, and pertussis (Tdap), and human papillomavirus (HPV) vaccines, respectively. For patients with DM in Saudi Arabia, the rate of vaccination for annual influenza and COVID-19 vaccines was higher compared to other vaccinations such as herpes zoster, Tdap, pneumococcal, and HPV. Factors such as vaccine recommendations provided by family physicians or specialists, site of care, income level, DM-related hospitalization history, residency site, hemoglobin A1c (HbA1c) level, and health sector type can significantly influence the vaccination rate in patients with DM. Among non-vaccinated patients with DM, the most reported barriers were lack of knowledge and fear of side effects. This signifies the need for large-scale research in this area to identify additional factors that might facilitate adherence to CDC/ACIP vaccine recommendations in patients with DM. CONCLUSION: In Saudi Arabia, patients with DM showed higher vaccination rates for annual influenza and COVID-19 vaccines compared to other vaccinations such as herpes zoster, Tdap, pneumococcal, and HPV. Factors such as vaccine recommendations provided by family physicians or specialists, the site of care, income level, DM-related hospitalization history, residency site, HbA1c level, and health sector type can significantly influence the vaccination rate in patients with DM.

Evaluating the health and economic outcomes of a PCV15 vaccination program for adults aged 65 years-and-above in Switzerland.

OBJECTIVE: To assess the health and economic outcomes of a PCV13 or PCV15 age-based (65 years-and-above) vaccination program in Switzerland. INTERVENTIONS: The three vaccination strategies examined were:Target population: All adults aged 65 years-and-above. Perspective(s): Switzerland health care payer. TIME HORIZON: 35 years. Discount rate: 3.0%. Costing year: 2023 Swiss Francs (CHF). STUDY DESIGN: A static Markov state-transition model. DATA SOURCES: Published literature and publicly available databases or reports. OUTCOME MEASURES: Pneumococcal diseases (PD) i.e., invasive pneumococcal diseases (IPD) and non-bacteremic pneumococcal pneumonia (NBPP); total quality-adjusted life-years (QALYs), total costs and incremental cost-effectiveness ratios (CHF/QALY gained). RESULTS: Using an assumed coverage of 60%, the PCV15 strategy prevented a substantially higher number of cases/deaths than the PCV13 strategy when compared to the No vaccination strategy (1,078 IPD; 21,155 NBPP; 493 deaths). The overall total QALYs were 10,364,620 (PCV15), 10,364,070 (PCV13), and 10,362,490 (no vaccination). The associated overall total costs were CHF 741,949,814 (PCV15), CHF 756,051,954 (PCV13) and CHF 698,329,579 (no vaccination). Thus, the PCV13 strategy was strongly dominated by the PCV15 strategy. The ICER of the PCV15 strategy (vs. no vaccination) was CHF 20,479/QALY gained. In two scenario analyses where the vaccine effectiveness for serotype 3 were reduced (75% to 39.3% for IPD; 45% to 23.6% for NBPP) and NBPP incidence was increased (from 1,346 to 1,636/100,000), the resulting ICERs were CHF 29,432 and CHF 13,700/QALY gained, respectively. The deterministic and probabilistic sensitivity analyses demonstrated the robustness of the qualitative results-the estimated ICERs for the PCV15 strategy (vs. No vaccination) were all below CHF 30,000/QALYs gained. CONCLUSIONS: These results demonstrate that using PCV15 among adults aged 65 years-and-above can prevent a substantial number of PD cases and deaths while remaining cost-effective over a range of inputs and scenarios.

Pneumococcal vaccine uptake among high-risk adults and children in Italy: results from the OBVIOUS project survey.

BACKGROUND: Streptococcus pneumoniae infections, including Invasive Pneumococcal Diseases (IPDs), pose a substantial public health challenge, causing significant morbidity and mortality, especially among children and older adults. Vaccination campaigns have played a vital role in reducing pneumococcal-related deaths. However, obstacles related to accessibility and awareness might impede optimal vaccine adoption. This study aims to provide comprehensive data on pneumococcal vaccine coverage and attitudes within at-risk groups in Italy, with the goal of informing public health strategies and addressing vaccination barriers. METHODS: Between April 11 and May 29, 2022, a questionnaire investigating vaccine uptake and attitudes toward several vaccinations was administered to 10,000 Italian adults, chosen through population-based sampling. Respondents who were targets of the campaign according to the 2017-2019 National Vaccination Plan, accessed questions regarding pneumococcal vaccination. Data on uptake, awareness of having the right to free vaccination, opinion on vaccine safety, concern with pneumococcal disease, and ease of access to vaccination services were summarized and presented based on statistical regions. Multinomial logistic regression analysis was used to explore factors influencing vaccine uptake. RESULTS: Out of 2357 eligible adult respondents (42.6% women; mean age: 58.1 ± 15.7), 39.5% received pneumococcal vaccination. Uptake differed among at-risk groups: respondents aged ≥65 (33.7%), with lung disease (48.4%), cardiovascular disease (46.6%), and diabetes (53.7%). Predictors of not being vaccinated and unwilling to included female gender, residing in rural areas, lower education, low concern about pneumococcal disease, vaccine safety concerns, and associations with vaccine-opposed acquaintances. Health access issues predicted willingness to be vaccinated despite non-vaccination. Pneumopathy, heart disease, diabetes, and living in Northeastern or Central Italy were linked to higher uptake. Among the 1064 parents of eligible children, uptake was 79.1%. Parental unawareness of children's free vaccination eligibility was a predictor of non-vaccination. Vaccine safety concerns correlated with reluctance to vaccinate children, while perceived healthcare access challenges were associated with wanting but not having received vaccination. CONCLUSIONS: Pneumococcal vaccination uptake within prioritized groups and children in Italy remains inadequate. Scarce awareness of vaccine availability and obstacles in accessing vaccinations emerge as principal barriers influencing this scenario.

Immunization with a whole cell vaccine reduces pneumococcal nasopharyngeal density and shedding, and middle ear infection in mice.

Pneumococcal Conjugate Vaccines (PCVs) have substantially reduced the burden of disease caused by Streptococcus pneumoniae (the pneumococcus). However, protection is limited to vaccine serotypes, and when administered to children who are colonized with pneumococci at the time of vaccination, immune responses to the vaccine are blunted. Here, we investigate the potential of a killed whole cell pneumococcal vaccine (WCV) to reduce existing pneumococcal carriage and mucosal disease when given therapeutically to infant mice colonized with pneumococci. We show that a single dose of WCV reduced pneumococcal carriage density in an antibody-dependent manner. Therapeutic vaccination induced robust immune responses to pneumococcal surface antigens CbpA, PspA (family 1) and PiaA. In a co-infection model of otitis media, a single dose of WCV reduced pneumococcal middle ear infection. Lastly, in a two-dose model, therapeutic administration of WCV reduced nasal shedding of pneumococci. Taken together, our data demonstrate that WCV administered in colonized mice reduced pneumococcal density in the nasopharynx and the middle ear, and decreased shedding. WCVs would be beneficial in low and middle-income settings where pneumococcal carriage in children is high.

Effects of sequential vs single pneumococcal vaccination on cardiovascular diseases among older adults: a population-based cohort study.

BACKGROUND: Recommendations around the use of 23-valent pneumococcal polysaccharide vaccine (PPSV23) and 13-valent pneumococcal conjugate vaccine (PCV13) seldom focus on potential benefits of vaccine on comorbidities. We aimed to investigate whether sequential vaccination with PCV13 and PPSV23 among older adults would provide protection against cardiovascular diseases (CVD) compared with using a single pneumococcal vaccine. METHODS: We conducted a Hong Kong-wide retrospective cohort study between 2012 and 2020. Adults aged ≥65 years were identified as receiving either a single or sequential dual vaccination and followed up until the earliest CVD occurrence, death or study end. To minimize confounding, we matched each person receiving a single vaccination to a person receiving sequential vaccination according to their propensity scores. We estimated the hazard ratio (HR) of CVD risk using Cox regression and applied structural equation modelling to test whether the effect of sequential dual vaccination on CVD was mediated via the reduction in pneumonia. RESULTS: After matching, 69 390 people remained in each group and the median (interquartile range) follow-up time was 1.89 (1.55) years. Compared with those receiving a single vaccine, those receiving sequential dual vaccination had a lower risk of CVD [HR (95% CI): 0.75 (0.71, 0.80), P < 0.001]. Post-hoc mediation analysis showed strong evidence that the decreased CVD risk was mediated by the reduction in all-cause pneumonia. CONCLUSIONS: Sequential dual pneumococcal vaccination was associated with lower risk of CVD compared with single-dose PCV13 or PPSV23 in older adults. Such additional CVD benefits should be considered when making decisions about pneumococcal vaccination.

Safety, tolerability and immunogenicity of a novel 24-valent pneumococcal vaccine in toddlers: A phase 1 randomized controlled trial.

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) significantly reduced pneumococcal disease burden. Nevertheless, alternative approaches for controlling more serotypes are needed. Here, the safety, tolerability, and immunogenicity of a 24-valent (1/2/3/4/5/6A/6B/7F/8/9N/9V/10A/11A/12F/14/15B/17F/18C/19A/19F/20B/22F/23F/33F) pneumococcal vaccine based on Multiple Antigen-Presenting System (MAPS) technology (Pn-MAPS24v) was assessed in toddlers. METHODS: In this phase 1, blinded, dose-escalation, active-controlled multicenter study conducted in the United States (September/2020-April/2022), 12-15-month-old toddlers primed with three doses of 13-valent PCV (PCV13) were randomized 3:2 to receive a single dose of one of three Pn-MAPS24v dose levels (1 µg/2 µg/5 µg per polysaccharide) or PCV13 intramuscularly. Reactogenicity (within 7 days), treatment-emergent adverse events (TEAEs, within 180 days), serious/medically attended adverse events (SAEs/MAAEs, within 180 days), and immunogenicity (serotype-specific anti-capsular polysaccharide immunoglobulin G [IgG] and opsonophagocytic activity [OPA] responses at 30 days post-vaccination) were assessed. RESULTS: Of 75 toddlers enrolled, 74 completed the study (Pn-MAPS24v 1 µg/2 µg/5 µg: 15/14/16, PCV13: 29). Frequencies of local (60 %/67 %/31 %) and systemic events (67 %/67 %/75 %) in the Pn-MAPS24v 1 µg/2 µg/5 µg and the PCV13 (55 %, 79 %) groups were in similar ranges. TEAEs were reported by 47 %/40 %/63 % of Pn-MAPS24v 1 µg/2 µg/5 µg recipients and 52 % of PCV13 recipients. No vaccine-related SAE was reported. At 30 days post-vaccination, for each of the 13 common serotypes, ≥93 % of participants in each group had IgG concentrations ≥0.35 µg/mL; >92 % had OPA titers ≥lower limit of quantitation (LLOQ), except for serotype 1 (79 %). For 7/11 unique serotypes (2/8/9N/11A/17F/22F/33F), at all dose levels, ≥78 % of Pn-MAPS24v recipients in each group had IgG concentrations ≥0.35 µg/mL and 80 %-100 % had OPA titers ≥LLOQ. CONCLUSIONS: In 12-15-month-old toddlers, a single dose of Pn-MAPS24v showed an acceptable safety profile, regardless of dose level; AEs were reported at similar frequencies by Pn-MAPS24v and PCV13 recipients. Pn-MAPS24v elicited IgG and OPA responses to all common and most unique serotypes. These results support further clinical evaluation in infants.

No Waning of Pneumococcal Vaccine Responses over Time in People with Inflammatory Arthritis: Findings from a Single Centre Cohort.

BACKGROUND: Vaccination against pneumococcus reduces the risk of infective events, hospitalisation, and death in individual with inflammatory arthritis, particularly in those on immunomodulating therapy who are at risk of worse outcomes from pneumococcal disease. The objective of this study was to investigate the serological protection following vaccination against pneumococcal serovars over time. Methods: This was a single centre, retrospective cohort study of individuals with rheumatoid arthritis, psoriatic arthritis, or axial spondylarthritis who had previously received the PPSV23 polysaccharide pneumococcal vaccine (Pneumovax). Data were retrieved between January 2021 to August 2023. Dates of previous pneumococcal vaccination were identified using linked primary care records. Serum serotype levels were collected. The primary outcome was serological response defined as a titre ≥0.35 mcg/mL in at least five from a total of 12 evaluated pneumococcal serovars, examined using a Luminex platform. Multivariate logistic regression models adjusting for age, gender, ethnicity, co-morbidities, and the use of prednisolone, conventional synthetic and biological DMARDs were used to determine the odds of a sustained serological response according to time categorised into ≤5 years, 5-10 years, and ≥10 years since vaccination. Results: Serological response was measured in 296 individuals with inflammatory arthritis, with rheumatoid arthritis the most common diagnosis (74% of patients). The median time between pneumococcal vaccine administration and serological assessment was 6 years (interquartile range 2.4 to 9.9). A positive serological response to at least 5 serovars was present in 195/296 (66%) of patients. Time since vaccination did not significantly associate with serological protection compared with those vaccinated <5 years, the adjusted ORs of vaccine response was 1.15 (95% CI 0.64 to 2.07) in those 5-10 years and 1.26 (95% CI: 0.64 to 2.48) in those vaccinated over 10 years ago. No individual variable from the multivariate model reached statistical significance as an independent predictor of vaccine response, although steroid use at the time of vaccine had a consistent detrimental impact on serological immunity. Conclusions: We demonstrated that antibody titres following vaccination against pneumococcal serovars do not appear to wane over time. It appears more critical to focus on maximising the initial vaccine response, which is known to be diminished in this patient population.

Exploring Perceptions and Practices Regarding Adult Vaccination against Seasonal Influenza, Tetanus, Pneumococcal Disease, Herpes Zoster and COVID-19: A Mixed-Methods Study in Greece.

We aimed to document vaccination coverage for five vaccines, predictors of each vaccine's uptake and attitudes regarding adult vaccination. Adults visiting four pharmacies were randomly invited to participate during summer 2022. Among 395 participants (mean age 51.2 years, range 19-96), vaccination rates were 78.1% for influenza and 25.8% for herpes zoster (≥60 years old), 64.3% for pneumococcal disease (≥65 years old), 33.1% for tetanus, while 11.4% had received two and 74.8% ≥3 COVID-19 vaccine doses. Half of participants (50.1%) voiced some degree of hesitancy, and 1.3% were refusers. The strongest predictor of each vaccine's uptake was doctor's recommendation (OR range 11.33-37.66, p < 0.001) and pharmacist's recommendation (4.01-19.52, p < 0.05), except for the COVID-19 vaccine, where the Attitude Towards Adult VACcination (ATAVAC) value of adult vaccination subscale's score was the only predictor (OR: 5.75, p < 0.001). Regarding insufficient coverage, thematic content analysis revealed seven main themes. Insufficient knowledge, the absence of health professionals' recommendation, perception of low susceptibility to disease, negligence and dispute of vaccine effectiveness were universal themes, whereas safety concerns and distrust in authorities were reported solely for COVID-19 vaccination. Designing public interventions aiming to increase trust in adult vaccination is essential in the aftermath of the COVID-19 pandemic. Health professionals' role in recommending strongly adult vaccination is crucial.

Compliance with recommended pneumococcal vaccination schedule in patients treated for rheumatoid arthritis: A retrospective cohort study in the Veterans Affairs population.

INTRODUCTION: Invasive pneumococcal disease (IPD) is a leading cause of death. Rheumatoid arthritis (RA) patients are at risk of IPD due to immunosuppressant medications. Up until 2022, two pneumococcal vaccines, the 13-valent Pneumococcal conjugate vaccine (PCV13) and pneumococcal polysaccharide vaccine (PPSV23), were recommended. Despite the recommendation change to give a single 20-valent PCV vaccine (PCV20), some still require multiple vaccinations. There is a need to identify barriers to vaccine uptake. METHODS: We conducted a retrospective cohort study to assess the on-time vaccination rates for PCV13 and PPSV23 in treated RA patients between 2010 and 2018 using national Veterans Affairs data. Patients > 18 years of age diagnosed with RA and newly initiated on RA treatment were included. Pneumococcal vaccine compliance was assessed by measuring on-time receipt of PCV13 and PPSV23 vaccinations. We identified factors using multivariate logistic regression and described the occurrence of these factors using descriptive statistics. RESULTS: A total of 39,243 patients were included in the study. Most patients were white (75.8 %), male (85.4 %), on methotrexate therapy (41.4 %). The average age was 62.3 years. The proportion of patients considered vaccine compliant is 43.9 %. The primary independent risk factors for vaccine non-compliance were black/African American race (Odds Ratio [OR] 1.26, 95 % Confidence Interval [CI] 1.19-1.34) or missing/unknown race (OR 1.45, 95 % CI 1.31-1.61), missing/unknown ethnicity (OR 1.21, 1.02-1.43), never married (OR 1.10, 95 % CI 1.02-1.19) or widowed (OR 1.23, 95 % CI 1.12-1.34), diagnosed with congestive heart failure (OR 1.10, 95 % CI 1.00-1.22), or dementia (OR 1.48, 95 % CI 1.16-1.91). The proportion of patients who were non-compliant in patients who were vaccine naïve was 32.1 % and the non-compliance rate for non-naïve patients was 65.3 %. CONCLUSIONS: Providers should identify barriers to pneumococcal vaccination in RA patients to improve compliance. Efforts to increase vaccination should be tailored to specific high-risk groups.

Streptococcus pneumoniae serotype 19A in hospitalized children with invasive pneumococcal disease after the introduction of conjugated vaccines in Lima, Peru.

BACKGROUND: The Pneumococcal conjugate vaccine (PCV) has decreased cases of invasive pneumococcal disease (IPD) worldwide. However, the impact of PCVs introduction may be affected by the serotype distribution in a specific context. METHODS: Cross-sectional multicenter passive surveillance study of IPD cases in pediatric patients hospitalized in Lima, Peru between 2016 and 2019 (after PCV13 introduction) to determine the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae. Serotyping was performed by a sequential multiplex PCR and confirmed by whole genome sequencing. RESULTS: Eighty-five S. pneumoniae isolates were recovered (4.07/100,000 among children <60 months of age). Serotype 19A was the most common (49.4%). Children infected with serotype 19A in comparison with children infected with other serotypes were younger, had a lower rate of meningitis and higher rates of pneumonia, complicated pneumonia and antimicrobial resistance; 28.6% of patients with serotype 19A have received at least one dose of PCV13 vs. 62.8% of patients with other serotypes. Using MIC-breakpoints, 81.2% (56/69) of non-meningitis strains and 31.2% (5/16) of meningitis strains were susceptible to penicillin; 18.8% (3/16) of meningitis strains had intermediate resistance to ceftriaxone. Resistance to azithromycin was 78.8% (67/85). Serotype 19A frequency increased over time in the same study population, from 4.2% (4/96) in 2006-2008, to 8.6% (5/58) in 2009-2011, to 49.4% (42/85) in the current study (2016-2019) (p < 0.001). CONCLUSIONS: After PCV13 introduction in Peru, serotype 19A remains the most prevalent; however, the vaccination coverage is still not optimal. Therefore, additonal surveillance studies are needed to determine the remaining IPD burden.