Dose Of Vaccine Research Articles

Routine Vaccination Coverage - Worldwide, 2023.

In 2020, the World Health Assembly endorsed the Immunization Agenda 2030 (IA2030), a 10-year strategy to reduce vaccine-preventable disease (VPD)-associated morbidity and mortality. IA2030 goals include improving equitable vaccination coverage, halving the number of unimmunized (zero-dose) children, and increasing the introduction of new and underutilized vaccines. The COVID-19 pandemic disrupted health systems worldwide, hindering years of childhood vaccination achievements and putting global public health goals at risk. This report presents trends in World Health Organization (WHO) and UNICEF routine vaccination coverage estimates through 2023 across the 194 WHO member countries. During 2022-2023, global coverage with the first and third doses of diphtheria-tetanus-pertussis-containing vaccine (DTPcv) (89% and 84%, respectively) and the first dose of measles-containing vaccine (83%) stagnated and remained lower than prepandemic levels. The 31 WHO member countries with fragile, conflict-affected, and vulnerable (FCV) settings include approximately one half of the world's 14.5 million children who did not receive the first DTPcv dose. The introduction of new and underutilized vaccines, such as a second MCV dose in the African Region, has improved countries' overall protection against VPDs. Accelerating country-specific routine immunization and catch-up vaccination programs to reach unvaccinated and incompletely vaccinated children, especially those living in FCV settings, is critical to reducing morbidity and mortality associated with VPDs.

Antibody Response After a Fifth Dose (Third Booster) of BNT162b2 mRNA COVID-19 Vaccine in Healthcare Workers.

Although a fourth dose of SARS-CoV-2 vaccine was shown to be effective, the immunogenicity of a fifth dose in immunocompetent individuals had not been well described. This was a prospective observational cohort study of previously vaccinated healthcare workers at a single tertiary hospital in Israel. Individuals were administered up to three booster doses of the BNT162b2 mRNA vaccine (i.e., up to five overall doses), during the period between July 2021 and January 2023. Immunogenicity was assessed using the SARS-CoV-2 IgG (sCOVG) semi-quantitative assay, performed at several time points. The cohort consisted of 162 individuals (median age 69 years, 62% female). Of these, 104 (64%) received four doses and 58 (36%) received five doses. Anti-SARS-CoV-2 antibody levels increased in all cases, regardless of the baseline levels. The fold-change increase in the mean sCOVG index was 29.2 (SD 2.6) after the third vaccine, 3.8 (SD 2.4) after the fourth vaccine, and 3.6 (SD 3.0) after the fifth vaccine. A waning effect over time was seen in 78% and 43% of participants for the third and fourth doses, respectively. Adverse events following the fifth dose were limited and mild. Similar to previous booster vaccines, a fifth dose of BNT162b2 is immunogenic and safe in healthy individuals, although the clinical implications remain unclear.

Expanding Horizons: Increasing Injectable Vaccine in the Expanded Program on Immunization

The World Health Organization started the Expanded Program on Immunization in 1974, including 6 antigens with up to 8 vaccine doses for childhood vaccination. The number of antigens has now increased to 11 antigens in 21 vaccines. The expansion of vaccination programs to include more antigens and doses has led to concerns about the burden of multiple injections on infants and children, as well as factors such as fear of adverse reactions, pain, and overall acceptability of vaccines. To address these challenges, there's a call for research to focus on developing combined vaccines that can be administered through more acceptable routes, such as oral, nasal, or needleless administration. This approach could potentially reduce the number of injections required and increase the willingness of individuals to receive vaccines. We highlight the importance of ongoing research and innovation in vaccine development and delivery methods to ensure that vaccination programs remain effective, efficient, and acceptable to the communities they serve, particularly in resource-limited settings.

Vaccination against COVID-19 in a geographically dispersed and underserved population, challenges and solutions in access and distribution of vaccines

Background As of July 2021, only 57% of Ecuador’s population had received the first vaccine dose against COVID-19. The national immunization campaign faced difficulties in reaching and providing vaccines to underserved population in remote areas. Methods The RISE project, funded by USAID and implemented by Jhpiego, aimed to develop an immunization strategy, that through the collaboration of an international non-profit organization, an academic institution and the public sector, could effectively support the national vaccination campaign of the Ecuadorian Ministry of Public Health. Results The program identified gaps in vaccination access and uptake, established specific strategies for targeted communities, analyzed official geographical information on vaccination coverage, ran micro-planning exercises at the local level, and adapted to new needs identified to ensure an effective vaccination uptake. From November 2021 up to May 2023, more than 1.8 million COVID-19 vaccine doses were administered to underserved populations living in geographically dispersed areas, in 18 provinces. Conclusions Employing data-targeted approaches and microplanning to identify underserved populations, strategic planning and collaboration between local governments, private sector, academic institution, and community leaders can substantially improve COVID-19 vaccines coverage and, thus, equity to vaccine access. The lessons learned might be useful to improve overall immunization service delivery.

Impact of gender-biased parental perceptions on under-immunization in Eastern Sudan: a cross-sectional study.

Despite global efforts, inequities in vaccine uptake remain, influenced by socioeconomic, geographic, cultural, and gender-related factors. In Eastern Sudan, gender disparities are acknowledged, particularly in livelihoods, but their impact on vaccination uptake is unclear. This study aimed to assess the effect of gender-biased parental perceptions on under-immunization among children in Kassala, Eastern Sudan. This study was a community-based cross-sectional in rural and urban districts of Kassala locality in Kassala State, Eastern Sudan in November 2022. Data were collected from parents using a pre-tested, structured questionnaire. The Chi-square or Fisher's exact test was conducted to assess the factors associated with under-immunization among children. Data were collected from 400 parents. Our data reveal that most children were fully vaccinated with the three doses of the pentavalent vaccine (83%), while 14% were partially vaccinated. Findings showed that about one in five parents perceived male vaccination as more important than female vaccination. This parental perception of gender-based importance in vaccination was significantly associated with under-immunization among children (p-value = 0.049). Additionally, males in our study are fully vaccinated 5% more often than females. Socio-economic factors, including mothers' education and households' income level, were also significantly associated with the vaccination status of the children. This study shed light on the effect of gender norms and related determinants on equitable access to vaccinations for boys and girls alike. More research is needed to gain a better understanding of the gender norms related to vaccination and their long-term impact on immunization demand and resilience in this region.

XBB.1.5-Adapted COVID-19 mRNA Vaccines but Not Infections With Previous Omicron Variants Boost Neutralisation Against the SARS-CoV-2 JN.1 Variant in Patients With Inflammatory Bowel Disease.

Variant-adapted COVID-19 vaccines are recommended for patients with inflammatory bowel disease (IBD). However, many patients rely on pre-existing immunity by original vaccines or prior infections. To assess whether such immunity sufficiently combats the highly immune-evasive SARS-CoV-2 JN.1 variant. Utilising two longitudinal cohorts, we evaluated immunity against JN.1 induced by original vaccines (IBD: n = 98; healthy: n = 48), omicron breakthrough infection (IBD: n = 55; healthy: n = 57) or XBB.1.5-adapted vaccines (IBD: n = 18). Neutralisation and anti-receptor-binding domain (RBD) IgG levels against wild-type SARS-CoV-2 and JN.1 were assessed using multiplex immunoassays. Study outcomes were wild-type and JN.1 neutralisation following three doses of original mRNA vaccines, stratified by immunosuppressive therapy (primary outcome), and JN.1 neutralisation following third-dose breakthrough infection or a fourth dose of XBB.1.5-adapted mRNA vaccines (secondary outcomes). Following original vaccines, JN.1 neutralisation was lower than wild-type neutralisation in all study groups (healthy, anti-TNF and non-anti-TNF; each p < 0.001); most individuals lacked JN.1 neutralisation (healthy: 97.9%; anti-TNF: 98.3% and non-anti-TNF: 92.3%). Confounder-adjusted multivariable modelling strongly associated anti-TNF therapy with low levels of anti-JN.1-RBD IgG (fold-change 0.48 [95% CI 0.39-0.59]). JN.1 neutralisation was similar in patients with or without breakthrough infection (anti-TNF, non-anti-TNF; each p > 0.05); neutralisation failure was 100% despite breakthrough infection. XBB.1.5-adapted vaccines enhanced JN.1 neutralisation (p < 0.001) and reduced neutralisation failure rates in patients with IBD (94.4% pre-vaccination vs. 44.4% post-vaccination; p = 0.003). Only variant-adapted vaccines protect against emerging SARS-CoV-2 variants. Patients with IBD and healthy individuals without recent vaccination may lack protection against the JN.1 subvariant KP.3 which causes current COVID-19 surges.

Long-term cardiovascular events in individuals hospitalised with COVID-19: a retrospective cohort

Abstract Background The post-COVID condition involves a range of persistent or new symptoms affecting various organs, including an increased risk of cardiovascular issues. As there are limited data on cardiovascular events in post-acute COVID-19 patients, we aimed to estimate their incidence and assess its association with patient and infection characteristics in Portugal. Methods We conducted a registry-based retrospective cohort study from seven hospitals across Portugal, including individuals hospitalised due to COVID-19 between March 2020 and March 2021. Our outcome of interest was cardiovascular events in the post-acute phase of COVID-19, occurring at least 30 days after the positive SARS-CoV-2 test. The variables of interest considered were the severity of the episode, existing cardiovascular risk and vaccination status before the SARS-CoV-2 test. Person-years and incidence rates were estimated. A Cox proportional hazard regression model was employed to assess risk factors. Results We included 1,803 patients in the analysis, of which 143 (7.9%) experienced at least one cardiovascular event following COVID-19 hospitalisation. The overall incidence rate of having at least one cardiovascular event was 34.65 per 1,000 person-years (95% confidence interval (CI): 29.20; 40.82). We found a higher risk of cardiovascular events for individuals with pre-existing cardiovascular risk (adjusted hazard ratio (aHR): 3.76, 95% CI: 1.53; 9.24) and lower risk for individuals with at least one vaccine dose before the SARS-CoV-2 test (partial - aHR: 0.44, 95%CI: 0.30; 0.64, complete - aHR: 0.46, 95%CI: 0.2; 0.80). We did not find a significant difference between the severity of the COVID-19 episode and the risk of having cardiovascular events post-COVID-19. Conclusions Our results indicate the presence of cardiovascular complications post-COVID-19, emphasising the need for healthcare systems to initiate screening and preventive strategies for individuals deemed at elevated risk. Key messages • COVID-19 vaccination decreases the risk of cardiovascular events post-COVID-19. • Healthcare systems should start screening and preventive strategies for individuals with pre-existing risk of cardiovascular events.

Empowering Educators: Italian Nurses’ Knowledge, Attitudes, Practices, and Vaccine Hesitancy

Abstract Background Vaccine hesitancy (VH) among healthcare workers is a prevalent global phenomenon and a public health concern. The study aims were i) identifying knowledge, attitudes, and practices (KAP); ii) estimating the prevalence of VH regarding recommended vaccines for healthcare workers (HWs). Methods Multicenter cross-sectional study of an Italian sample of nurses and nursing students. Following a systematic review (PROSPERO ID:CRD42020212252), a validated questionnaire was used (Cronbach’s alpha=0.82). Two multivariable logistic regression model were built to identify predictors of (1) VH to the recommended vaccine for HWs; (2) acceptance of the fourth COVID-19 vaccine dose. Results 226 participants were enrolled (169 nurses; 57 students). Regarding KAP: only four nurses (1.8%) had adequate knowledge among vaccine recommended for HWs, whereas 30% (N = 66) reported never having recommended vaccinations during clinical practice. 106 (46%) nurses/students reported VH for at least one of the vaccines recommended for HWs - high levels of VH were recorded for influenza vaccination (N = 88,38.9%) and fourth COVID-19 vaccine dose (N = 100,44.3%). At the multivariable analysis, (1) significant associations with highest levels of VH were found for nurses who reported having at least one child (OR:5.42, 95%CI: 1.64-17.89) and who had not received any dose of influenza vaccination in the last 5 years (OR:13.25, 95%CI: 5.29-33.16). Lowest odds of VH was found for nurses employed in Primary Health Care (OR:0.17, 95%CI: 0.03-0.98); (2) routinely recommending vaccinations during practice (OR:0.38, 95% CI: 0.15-0.95) was associated with acceptance of fourth COVID-19 vaccine dose. Conversely, reliance on social media as the primary information source seemed to be a predictor of COVID-19 vaccine refusal (OR:2.05 95% CI: 1.31-3.20). Conclusions Preliminary results identified predictors of VH among nurses, offering insights for organizations to effectively tailor public health interventions. Key messages • High levels of vaccine hesitancy among nurses towards recommended vaccines for healthcare workers pose a threat to patient safety. • Empowering ‘educators’ through focused public health interventions is essential to address factors contributing to vaccine hesitancy among healthcare workers.

Knowing the Antibody Status may influence compliance of health care workers to COVID-19 booster dose

Abstract Background Previous studies showed that the fourth SARS-CoV-2 vaccine dose has a protective effect against infection, as well as against severe disease and death. This study aimed to examine whether knowledge of a high level antibody after the 3rd dose may reduce compliance to the 4th booster dose among health care workers. Methods We conducted a prospective cohort study among health care workers vaccinated with the first three doses at Rambam Healthcare Campus, a tertiary hospital in northern Israel. Participants underwent a serological test before the 4th booster vaccine was offered to all of them, with results provided to participants. The population was divided into two groups: those with antibody below 955 AU/ml, and those with 955 AU/ml and higher, a cutoff found protective in a previous study. Multiple logistic regression was carried out to compare the compliance to the 4th booster between the two groups, adjusted for demographic and clinical variables. Results After adjusting for the confounding variables, the compliance was higher in those with antibody levels below 955 AU/ml (OR = 1.41, P = 0.05, 95% CI 1.10-1.96). In addition, male sex, and age of 60 years and above were also associated with higher vaccination rate (OR = 2.28, P &amp;lt; 0.001, 95% CI 1.64 - 3.17), (OR = 1.14, P = 0.043, 95% CI 1.06 - 1.75), respectively. Conclusions Knowledge of the antibody status may affect compliance with the booster dose. Considering waning immunity over time, reduced compliance may affect the protection of health care workers who declined the 4th dose. Key messages • Knowing the antibody status may affect compliance of health care workers with the booster dose. • Reduced compliance of health care workers may affect their protection.

Navigating vaccine procurement and financing challenges in Cameroon: Insights and recommendations from a mixed-methods study (2015–2020)

ObjectivesVaccine stockouts at the national level has been recognized as a critical challenge in ensuring sustained and equitable immunization coverage. These stockouts often arise from inherent issues within countries, including delays in government funding, suboptimal forecasting and stock management practices, and inefficiencies in the procurement process amongst others. Understanding the complexities and barriers within vaccine procurement and financing systems is crucial for developing effective strategies to enhance vaccine availability and strengthen immunization programs. This is particularly relevant in the context of reaching zero dose children and transitioning from Gavi. This study aimed to comprehensively assess the vaccine procurement and financing landscape in Cameroon from 2015 to 2020. Study designThis was a descriptive cross-sectional study. MethodsEmploying a mixed-methods approach, we conducted a desk review of pertinent documents and engaged in in-depth interviews with key stakeholders involved in the procurement and funding mobilization processes. Through data collection and analysis using Microsoft Excel 365 and Dedoose software, we delineated the intricacies of the procurement process and pinpointed specific barriers that have contributed to vaccine stockouts. ResultsThe mapping of vaccine procurement processes revealed complexity, protracted timelines, and the involvement of multiple stakeholders. The Expanded Program on Immunization (EPI) faced a USD 4 million funding deficit for vaccine procurement between 2016 and 2019. Consequently, the program experienced delays in acquiring 20 million vaccine doses, leading to 41 months of stockout for at least one antigen. Major bottlenecks identified by key stakeholders in vaccine procurement and financing encompassed delayed fund mobilization, inefficient and lengthy processes for fund mobilization and disbursement, poor data utilization, and discrepancies between forecasted, allocated, and mobilized funds. ConclusionThe findings of this research hold significant implications for many EPIs. By elucidating procurement and financing challenges, we can formulate evidence-based recommendations aimed at optimizing resource allocation, streamlining procurement processes, and bolstering vaccine availability. These insights are essential for fostering collaboration between government agencies, technical partners, and financial partners to achieve sustainable vaccine access in Cameroon. Establishing a joint procurement working group could streamline processes, potentially reducing stockouts and improving vaccine coverage.

The role of sociodemographic factors on herpes zoster vaccine uptake among hard-to-reach populations

Abstract Background The anti-Herpes Zoster (HZ) vaccination program was expanded with the adjuvated recombinant vaccine (HZR) in the Lazio Region, Italy, in 2022, restricting its use only to certain categories at risk due to pathological conditions, such as dialysis patients or immunocompromised individuals. This study focuses on the role of clinical and socio-demographic factors on HZR vaccine uptake within the fragile resident population of the Local Health Authority Rome 2 (ASL RM2). Methods This population-based, retrospective cohort study leveraged data from various registries and databases. The study population comprised 835,779 individuals aged ≥18 years who were both RM2 residents and registered with an RM2 general practitioner (GP). Among these, 143,242 individuals with at least one chronic condition were assessed for vaccination uptake using a multivariate logistic model, exploring associations with gender, age, nationality, marital status, household size, and level of deprivation. Results At the conclusion of the study period, a small fraction (1.5%) of the fragile subjects had received at least one dose of the HZR vaccine, and a majority (78%) completed the vaccination course of two doses. The analysis indicated that vaccine adherence was significantly higher in males (OR = 1.15) and individuals aged 65 + (OR = 1.13) while lower among residents in areas of medium (OR = 0.61) and high deprivation (OR = 0.44) and with specific living arrangements - widowed people living alone (OR = 0.66) and families ≥ 6 people (OR = 0.63). Conclusions The ASL RM2 vaccination strategy for hard-to-reach individuals includes an integrated approach, with the engagement of local healthcare facilities and hospitals. Despite these efforts, lower adherence in socioeconomically disadvantaged fragile patients suggests a pressing need for targeted communication strategies and interventions to ensure equitable access to the HZ vaccine, as these groups are more vulnerable to developing chronic diseases. Key messages • Socio-demographic factors significantly influence Herpes Zoster vaccine uptake in hard-to-reach populations, with lower adherence in socially deprived groups. • Tailored, equity-driven approaches are essential for enhancing vaccine coverage among hard-to-reach fragile individuals, mitigating the higher disease risks in these communities.

Measles cluster in Northern Portugal: enhancing surveillance strengths

Abstract Although measles was declared eliminated in Portugal in 2015, outbreaks persist, despite high vaccination coverage. The last outbreak in the northern region was in 2017. Portugal has a Surveillance System implemented for mandatory communicable diseases (SINAVE) integrating clinical, epidemiological and laboratory data. In 2021, WHO expressed concern about the low sensitivity of measles surveillance and urged Portugal to strengthen its surveillance practices. Our study aims to describe a measles cluster in northern Portugal during the first trimester of 2024. Data from measles cases from the first trimester of 2024 were collected from SINAVE. Contact tracing and Public Health (PH) intervention data was sent by Local Public Health Authorities through a survey designed for that purpose. A total of 70 suspected cases were reported and investigated: 6 cases were laboratory confirmed and 64 were discarded. The confirmed cases had a mean age of 28 years (all adults), with 50% female. The mean notification time was 0,3 days. The index case was imported (Mauritania) and unvaccinated, leading to 2 secondary cases. Five cases had 2 doses of a measles vaccine, with 1 case being a health professional. Additionally, 1 case was imported from France. For 2 cases the source of infection could not be unequivocally identified and no travel history during incubation period. A total of 851 contacts of confirmed cases were identified. Although sustainable transmission is not evident in our region, measles is being introduced through migration and tourism. Despite clinical awareness, strengthening early case detection is essential to enforce effective control measures. PH teams have been working tirelessly to trace clusters origins, gathering large number of contacts and adapting strategies for sustained control. In a globalized world, ensuring surveillance sensitivity is paramount. Integrating other data sources in surveillance routine is crucial for upholding Measles-Free Status compliance. Key messages • Measles must take centre stage on our agenda. • Reinforcing surveillance, integrating additional data sources, is crucial for heightened sensitivity and prompt response.

Substantial morbidity and mortality due to cardiovascular diseases in hospitalized vaccinated and un-vaccinated patients with COVID-19 from 16 countries: the WHF COVID-19 Long-term study

Abstract Background Long-term adverse consequences of the COVID-19 affect many organ systems, and this requires the identification and appropriate care of diverse symptoms. Purpose The World Heart Federation (WHF) international study describes the burden of clinical sequelae of COVID-19 up to 1 year after hospitalization, including patients from low- middle-and high-income countries. Methods We prospectively recruited patients hospitalized due to COVID-19 from 16 countries between January 2022 and June 2023. Patients were followed up at 1, 3, 6, and 9-12 months after hospital discharge. A standardized questionnaire administered by telephone collected data on long COVID symptoms, quality of life using the EuroQol 5 Dimension scale (EQ-5D), and disease outcomes including new onset diabetes and hypertension, major adverse cardiovascular events (MACE), and mortality. We report a descriptive analysis including demographic characteristics and outcomes up to one year after initial hospitalization. Results Of 2504 patients, the majority were Asian (78%), and male (56%). Mean age was 59.2 years (SD 19.9). Low- and lower-middle-income country participants constituted 65% of the cohort, with upper middle-income and high-income representing 20% and 15%, respectively. Follow-up rate was complete for 86%. 55% had received at least two doses of COVID-19 vaccination. At 1 month, 63% reported at least one persistent symptom, which decreased to 28% at 9-12 months. Fatigue was reported by 45% at 1-month and 17% at final follow-up. Anxiety occurred in 20% and 9% at these respective timepoints, and breathlessness in 12% and 6%. At 9-12 months, moderate to severe impairment of usual activities as measured by EQ-5D occurred in 19%, anxiety/depression in 10%, and mobility problems in 10%. The most frequent post-discharge new-onset illnesses were pulmonary embolism (7%), kidney problems (4%), and hypertension (3%). In-hospital mortality was 4% (n=102), and a further 12% (265 patients) died by one-year. The most common cause was sudden cardiac death (59%), respiratory disease including pulmonary embolism (13%), and stroke (6%). Conclusions We observed a significant burden of post-COVID-19 complications with one fifth of patients with persistent difficulties in usual activities at one year. This underscores the urgent need to understand the underlying mechanisms for organ damage and death, and for targeted preventive strategies and proactive management approaches to reduce them.

Introducing vaccination services in prison settings: case study from Moldova

Abstract Introducing vaccination services within prison settings presents a multifaceted challenge and opportunity, particularly evident in the case of Moldova. This Eastern European nation grapples with various socio-economic and healthcare disparities, with its prison population often experiencing heightened health vulnerabilities. Amidst such complexities, the implementation of vaccination services emerges as a crucial strategy not only to safeguard the health of incarcerated individuals but also to contribute to broader public health goals. Moldova’s journey in this regard reflects a commitment to advancing preventive healthcare within its correctional facilities. The introduction of vaccination services in prisons necessitated a comprehensive approach, encompassing policy development, infrastructure enhancement, staff training, and community engagement. Infrastructure enhancement was imperative to ensure the provision of vaccination services in a safe, efficient, and dignified manner within prison settings. This involved the establishment of designated vaccination areas equipped with the necessary medical supplies and equipment. Staff training emerged as a cornerstone of the initiative, empowering healthcare professionals working within prisons with the knowledge, skills, and confidence to deliver vaccination services effectively. Training programs encompassed various aspects, including vaccine administration, adverse event management, and communication strategies tailored to the specific needs of incarcerated individuals. Collaboration with people living in prison facilitated the dissemination of accurate information, addressed concerns, and encouraged participation in vaccination programs. During the period 2021-2023 7454 doses of antiCOVID-19, 1298 doses of anti-Flu vaccine, 3083 doses of anti-HBV vaccines were administered.

COVID-19 vaccine associated myocarditis in Norway - a nationwide validation study

Abstract Background The SARS-CoV-2 pandemic led to worldwide initiation of vaccination campaigns. The new mRNA vaccines were unexpectedly associated with vaccine-associated myocarditis (VAM). The incidence and severity of VAM has not been validated in a nation-wide and well-defined population. From December 2020 onwards the mRNA vaccines Comirnaty and Spikevax have been in widespread use in Norway. The National Patient Register (NPR) includes all hospital contacts with corresponding diagnostic codes (ICD-10), and all vaccinations are registered in the Norwegian Immunization Register (SYSVAK). Purpose We aimed to identify and validate all cases of suspected COVID-19 VAM in Norway during the national vaccination campaign between 2020-22. Methods We identified all cases of myocarditis acquired within 90 days of a COVID-19 vaccination through linkage of diagnostic codes for myocarditis in NPR and vaccination data in SYSVAK. Cases were included from December 2020 through April 2022. We assessed medical records, cardiac imaging, and biochemistry to retrospectively validate all myocarditis cases. The Brighton Criteria (international criteria for myocarditis diagnosis following immunization with defining levels of diagnostic certainty) were used to confirm the VAM diagnosis. Results From December 2020 to April 2022, 4 114 750 unique subjects (2 036 792 men and 2 077 958 women, median age first dose 47 years) above 16 years of age, received 10 915 098 unique doses of COVID-19 vaccines (8 651 703[79%] Comirnaty and 2 263 395[21%] Spikevax). Of 277 cases of myocarditis identified in NPR&amp;lt;90 days after receiving a COVID-19 vaccine, 176(64%) were validated as VAM (78 definite, 90 probable, and 8 possible VAM). Among the patients with VAM, 137(78%) were men with median age 30(IQR 24-47) years, and 39(22%) were women with median age 54(IQR 32-65) years. There were 4 cases of VAM per 100 000 vaccinated subjects: 7 per 100 000 men and 2 per 100 000 women. Sixty-three percent of VAM occurred after the second mRNA vaccine dose. There were 3.3 cases of VAM per 100 000 unique doses of Spikevax compared to 1.1 per 100 000 unique doses of Comirnaty. The most common time interval from vaccination to VAM was 3 days and occurred in 30 patients (17.3% of VAM, 93% men), and 34% of VAM (90% men) occurred during the first 5 days from vaccination(Figure). Median duration of hospital stay was 4(IQR 3-5) days, with only 7(4%) patients needing intensive care and 1 myocarditis related patient death during hospitalization. Conclusions In this unique nationwide study including all COVID-19 vaccinated subjects in Norway from 2020-22 we found 4 cases of VAM per 100 000 vaccinated subjects. The majority of VAM occurred in young men. Interestingly, women presented later than men with VAM and most frequently at middle to older age. The occurrence of this unexpected serious adverse event underscores the importance of large studies in broad populations in future vaccine programs.

Pertussis on the territory of Serbia in 2024 - challenges and opportunities for the future

Abstract Introduction Surveillance of pertussis in Serbia is passive surveillance and every 3 to 4 years an increased number of positive cases are registered in the population. The last quarter of 2023 and the first quarter of 2024 are characterized by an increased number of pertussis cases. Methods Descriptive study of cases with confirmed pertussis in the territory of the Republic of Serbia based on the evidence by the Public Health Service System of the Institute of Public Health of Serbia Results According to data from the Public Health Service System in the Republic of Serbia, a total of 1348 confirmed cases of pertussis were registered by the end of April 2024 (incidence rate 20.2 per 100,000 inhabitants). Conclusions The largest number of cases was registered in the age groups of people older than 20 years, that is, aged 10 to 14 years, while the highest age-specific incidence rate was recorded in the age group of infants younger than 12 months and in children aged 10 to 14 years. Of the total number of reported cases, 120 (8.9%) were hospitalized, with the largest number of those hospitalized being in the age group younger than 12 months (85, ie 70.8% of hospitalized cases). As for the territorial distribution, the largest number of pertussis cases in relation to the place of residence was reported from the territory of two districts, Južnobački District and the City of Belgrade, where the highest incidence rates were also registered. The postponement of timely vaccination against pertussis and the impossibility of vaccinating newborns up to 2 months of age have influenced the increase in the number of infected persons. Also, advanced PCR diagnostics during Covid and the possibility of applying PCR diagnostics in pertussis helped the timely diagnosis of pertussis. The introduction of vaccination with another dose of acellular pertussis vaccine and vaccination of pregnant women would be a desirable public health intervention to prevent pertussis infection. Key messages • Protection of the target population before starting school and at the age of 14 will contribute to stopping the occurrence of new cases of pertussis. These are public health challenges. • PCR diagnosis of pertussis influenced the timely diagnosis of this infection and the possibility of its adequate and timely treatment.

Vaccination Coverage among Institutionalized Elderly Population: A Case Study in Cascais, Portugal

Abstract Vaccination stands as a cornerstone of public health, significantly reducing the morbidity and mortality associated with infectious diseases. However, the aging demographic, with declining homeostasis and immunosenescence, presents new challenges. Those residing in nursing homes face heightened risks of infectious diseases due to proximity and interactions with multiple staff members. In Portugal, elderly vaccination against tetanus/diphtheria (Td) is integrated into the National Vaccination Program, with additional official recommendations for pneumococcal (Pn), seasonal influenza, and COVID-19 vaccinations. Specific vaccination campaigns in nursing homes for influenza and COVID-19 are coordinated by Public Health Units. This study aimed to assess the vaccination coverage for these vaccines among the institutionalized elderly in Cascais municipality and evaluate the implementation of official recommendations. A survey of nursing homes in Cascais was conducted, and the vaccination status of residents was assessed through electronic records in February 2024. Statistical analysis was performed. Vaccination status for each vaccine was considered valid if individuals had received at least one dose of Pn13 or Pn23, a Td vaccine dose within the last 10 years, and vaccinations against influenza and COVID-19 within the last 6 months. Among 2189 institutionalized elderly in Cascais, 87% were vaccinated against both influenza and COVID-19, 39% against Td, and 17% against pneumococcal disease. While influenza and COVID-19 vaccination coverage is high, the tetanus/diphtheria vaccination rate is low, and pneumococcal vaccination is very low, despite official recommendations. This population remains at increased risk for preventable diseases. Monitoring vaccination status and implementing targeted vaccination campaigns are crucial for increasing coverage, realizing health and economic benefits and preventing severe diseases. Key messages • Vaccination is essential for safeguarding the health of institutionalized elderly populations. There is a need for targeted interventions to address preventable diseases and protect these individuals. • Monitoring vaccination status and implementing targeted campaigns are critical for increasing coverage and realizing health and economic benefits among elderly populations in nursing homes.

Vaccination campaign implementation in Madagascar: a Dynamic Sustainability Framework approach

Abstract Background The COVID-19 pandemic has highlighted the need for equitable and timely access to vaccination. Limited evidence is available on how to implement vaccination campaigns (VCs) that are sustainable and responsive to changes in real-world health policy and practice contexts. We present lessons learned from the implementation of a COVID-19 VC in the Boeny region of Madagascar. Methods Informed by the Dynamic Sustainability Framework, VC implementation was continuously reviewed during multisectoral stakeholder feedback rounds, key informant interviews, and problem-solving meetings to identify and put key adaptations throughout the campaign process into practice. Outcome indicators include pre- and post-VC vaccine hesitancy and trends in vaccine doses deployed were analyzed using generalized linear models. Results Key adaptations of the implementation strategy included community-led awareness-raising and outreach activities also in remote areas, strengthening VC through the training of 340 staff, and addressing gaps identified in the cold chain, waste management, vaccine transportation, and IT equipment. Overall, 24888 COVID-19 vaccines were administered in six months. Changes in campaign strategy increased the number of doses administered by 8% (RR = 1.08; CI 95%: 1.01; 1.15) per week. No changes in vaccine hesitancy post-VC were observed in an unvaccinated population(Δ = 0.02, CI 95%: -0.04; 0.08). Conclusions Collaborative and dynamic multi-sectoral VC strategies that combine healthcare-based approaches with pro-active outreach and community-led awareness-raising activities are essential in increasing vaccine uptake in limited-resource settings. Our findings show that despite boosting vaccination coverage, such initiatives may not have an impact on COVID-19 vaccine hesitancy at the community level Key messages • Multisectoral stakeholder collaboration and engagement are key to successful vaccination campaign implementation. • A Dynamic Sustainability Framework approach can be effective in ensuring a continuous fit between campaign and its setting.

Estimated number of COVID-19 deaths averted by vaccination in Belgium

Abstract Background Vaccination campaigns have been rolled out globally to limit the impact of COVID-19 on severe health outcomes, including mortality. We aimed to estimate the number of averted deaths by COVID-19 vaccination in the Belgian population aged ≥65 years, between January 2021 and January 2023. Methods Nationwide data on COVID-19 infections, vaccinations and all-cause mortality were individually linked. We estimated Vaccine Effectiveness against COVID-19 mortality (VE) in persons having received a vaccine dose in the last 6 months using a Cox proportional hazards model adjusted for age, sex, time since vaccination, previous infection, comorbidities, province and income. COVID-19 death was defined as a death within 1-7 weeks after a positive SARS-CoV-2 laboratory-test. Based on obtained VE estimates, vaccine coverage and national COVID-19 mortality data, we estimated the number of averted deaths (expected deaths without vaccinating minus the reported deaths). Results By January 31st 2023, 11,033 COVID-19 deaths have been reported in Belgium. The average vaccine coverage was 48% during alpha, 85% during delta and 63% during omicron dominance. VE was estimated at 0-59 days after vaccination, for 65-79 year and ≥80 year-olds respectively, at 65% (58%-60%) and 35% (28%-41%) during Alpha, at 84% (82%-87%) and 79% (77%-81%) during Delta and at 83% (80%-85%) and 71% (68%-73%) during Omicron dominance. We estimated 10,042 deaths averted (range: 8,917-11,188) among the Belgian population aged ≥65 years, representing a 48% reduction (range 45%-50%) in the expected deaths. Out of 10,042 averted deaths, the majority was averted during Delta (47%; 4,670) or Omicron dominance (43%; 4,366), compared to during Alpha dominance (10%; 1,006). Conclusions Vaccinating against COVID-19 led to an important reduction in COVID-19-related mortality among the Belgian population ≥65 years, in particular during Delta and Omicron dominance, underscoring the effectiveness of vaccines against mortality. Key messages • Vaccinating against COVID-19 led to an important reduction of 48% in COVID-19-related mortality among the Belgian population ≥65 years, in particular during Delta and Omicron dominance. • Vaccine effectiveness against COVID-19 mortality was estimated as high in the Belgian population ≥65 years (range: 71-84%) during Delta and Omicron dominance, also among elderly over 80 years.

ChineseCVD: a web-based Chinese-specifi c cardiovascular risk calculator incorporating long COVID, COVID-19vaccination, SGLT2i and PCSK9i treatment effects

Abstract Background Web-based risk prediction tools for cardiovascular diseases are crucial for providing rapid risk estimates for busy clinicians, but there is none available specifically for Chinese subjects. This study developed ChineseCVD, a risk calculator for cardiovascular disease. Methods Adult patients attending government-funded family medicine clinics in Hong Kong between 1st January 2000 and 31st December 2003 were included. The primary outcome was major adverse cardiovascular events (MACE) defined as a composite of myocardial infarction, heart failure, transient ischaemic attacks/ischaemic strokes, and cardiovascular mortality. Results A total of 155,066 patients were used as the derivation cohort. Over a median follow-up of 16.1 (11.6-17.8) years, 31,061 (20.44%) had MACE. Cox regression identified male gender, age, comorbidities, cardiovascular medications, systolic and diastolic blood pressure, and laboratory test results (neutrophil-lymphocyte ratio, creatinine, ALP, AST, ALT, HbA1c, fasting glucose, triglyceride, LDL and HDL) as significant predictors of the above outcomes. ChineseCVD further incorporates the impact of smoking status, COVID-19 infection, number of COVID-19 vaccination doses, and modifier effects of newest medication classes of PCSK9i and SGLT2i. The calculator enables clinicians to demonstrate to patients how risks vary with different medications. Conclusions The ChineseCVD risk calculator enables rapid web-based risk assessment for adverse cardiovascular outcomes, thereby facilitating clinical decision-making at the bedside or in the clinic.