Dose Of Vaccine Research Articles

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.

Does a correlation exist between delayed vaccination and a decreased vaccine confidence?

ABSTRACT Delay in vaccination schedule may result in increased risk of vaccine-preventable outbreaks. Lack of parental confidence in vaccines and sociodemographic factors could be related to those delays. Vaccine Confidence Index (VCI) is an indicator to estimate confidence in vaccines, composed of simple dimensions about it and evaluated using a 5-point Likert scale. Objectives of this study, conducted in the Region of Murcia, Spain, were to determine which sociodemographic factors were associated with delayed administration in measles, mumps and rubella (MMR) vaccine, both first and second doses, and to evaluate if there were differences in parental vaccine confidence of children who were delayed on MMR vaccine schedule compare to vaccinated on time. The 2019–2020 (first dose) and 2016–2017 (second dose) cohorts were divided into four categories: vaccinated on time, slightly delayed, moderately delayed and highly delayed. Online questionnaire was sent to their parents, followed by a telephone questionnaire for non-responders. Regarding MMR first dose, a significant association was found between delay and birth order and intellectual/motor delay of children. Parental educational status, the main source of vaccine information and the social networks more frequently used by parents were also associated with delay. Suffering motor/intellectual delay and the obstacles to vaccination process derived from caring for other siblings were associated with delay in second MMR dose. The VCI decreased significantly in first dose group as delay increases but did not change in the second one. Confidence in vaccines and sociodemographic factors, respectively, were associated with delaying MMR first and second dose.

Routine vaccination coverage at ages 2 and 7, before, during, and after the COVID-19 pandemic: Results from the STARVAX surveillance system.

A decline in routine vaccination coverage in children has been observed after the onset of the COVID-19 pandemic, but it is unclear whether these declines were sustained over time. This analysis assessed changes in vaccination coverage at ages 2 and 7years for routinely administered vaccinations before, during, and after the COVID-19 pandemic. Vaccination coverage was measured using yearly data from the Standardized Reporting on Vaccination (STARVAX) surveillance system between December 31, 2019, and December 31, 2023. Four provinces (Alberta, Saskatchewan, Manitoba, and New Brunswick) and one territory (Yukon) produced reports from their immunization registries and provided the Public Health Agency of Canada with the numbers of vaccinated 2-year-old and 7-year-old children. Population estimates from Statistics Canada and the Yukon Bureau of Statistics were used as the denominators. There was a decline in vaccination coverage in 2023 compared to 2019. In 2-year-olds, coverage for one dose of the measles, mumps, and rubella (MMR) vaccine and four doses of the diphtheria, tetanus, and acellular pertussis (DTaP) vaccine decreased from 89.5% to 82.5% and from 79.9% to 72.1%, respectively. Among 7-year-olds, DTaP (up-to-date) and MMR (two doses) vaccination coverage decreased from 77.1% to 68.8% and 86.3% to 75.6%, respectively. These declines are of concern and suggest that health care professionals should provide parents with accurate information regarding vaccines and encourage them to have their children vaccinated and keep vaccinations up to date.

Immunogenicity and Safety of the Recombinant Adjuvanted Herpes Zoster Vaccine in Patients with Chronic Lymphocytic Leukemia and Multiple Myeloma

Background/objectives: Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are susceptible to viral infections, including varicella-zoster virus (VZV) reactivation due to both disease-related and treatment-induced immunosuppression. The recombinant adjuvanted herpes zoster vaccine (RZV) has shown high efficacy in immunocompetent adults, but immunogenicity data in CLL and MM patients are limited. This study evaluates the immunogenicity and safety of RZV in this population. Methods: Patients with CLL and MM vaccinated with RZV (administered in two doses at least one month apart) were included in the study. Pre- and post-vaccination anti-VZV IgM and IgG antibody levels were measured to assess immunogenicity, and adverse events (AEs) were captured for safety evaluation. Results: Seventy-eight patients received both vaccine doses, and 71 had post-vaccination samples. Most of the patients were IgM seronegative and IgG seropositive before vaccination. Pre-vaccination IgG levels were higher in CLL patients compared to MM patients (p = 0.001), while post-vaccination IgG levels significantly increased in both CLL (p < 0.0001) and MM (p < 0.0001) patients. In actively treated CLL patients, pre-vaccination IgG levels were significantly lower than in not actively treated patients (p = 0.002). Post-vaccination IgG levels were lower in MM patients receiving antiviral prophylaxis concurrently with the vaccination (p = 0.013). AEs were reported in 49.4% of patients after the first dose and 48.7% after the second dose, mostly mild (local or low-grade systemic). One case of immune thrombocytopenia was noted. Conclusions: RZV demonstrated strong immunogenicity and acceptable safety in CLL and MM patients, significantly boosting IgG levels, even in actively treated or heavily pretreated patients.

The Health and Economic Benefits of United States Investments in Measles and Rubella Control and Elimination

Background: Prior to measles vaccine introduction in 1963, measles virus caused hundreds of thousands of annual reported cases, which led to substantial US morbidity, mortality, and costs. Similarly, congenital rubella syndrome (CRS) led to highly visible and tragic lifelong disability for thousands of Americans, before rubella vaccine introduction in 1969. The US certified national virus transmission elimination of indigenous measles in 2000 and rubella in 2004. Methods: Applying an existing integrated transmission and economic model, this analysis characterizes the net benefits of US investments in measles (1963–2030) and rubella (1969–2030) immunization assuming continued high routine immunization coverage. Due to importation risks, the US maintains two doses of both vaccines in its routine immunization schedule. Results: This analysis estimates total US costs of 8.1 billion (economics reported in 2023 US dollars) for measles immunization for 1963–2023 and 14.1 billion for rubella immunization for 1969–2023. The analysis estimates an additional approximately 1.2 billion for measles immunization and 1.5 billion for rubella immunization expected for 2024–2030. Historical and future US investments prevented an estimated approximately 237 million measles infections, 228,000 measles deaths, 193 million rubella infections, and 166,000 CRS cases. These investments imply net benefits (from avoided treatment costs minus immunization costs) of approximately 310 billion for measles and 430 billion for rubella and CRS, even without incorporating avoided productivity losses and intangible costs. Conclusions: US investments in measles and rubella immunization continue to provide enormous savings of human and financial costs and to prevent substantial mortality and morbidity.

A multivalent RSV vaccine based on the modified vaccinia Ankara vector shows moderate protection against disease caused by RSV in older adults in a phase 3 clinical study

Respiratory syncytial virus (RSV) causes a significant disease burden in older adults. The live recombinant vaccine based on a nonreplicating modified vaccinia Ankara (MVA-BN) poxvirus, MVA-BN-RSV, encoding for multiple proteins of RSV subtypes A and B, was assessed for efficacy against respiratory disease caused by RSV.Adults aged ≥60 years, with or without underlying chronic conditions, were enrolled and randomized in a 1:1 ratio to receive a single dose of vaccine or placebo and were followed for disease caused by RSV infection during the 2022–2023 season. The 2 primary endpoints were RSV-associated lower respiratory tract disease (LRTD) with ≥3 and ≥ 2 symptoms; acute respiratory disease (ARD) was a key secondary endpoint. The humoral RSV-specific immune response was assessed at baseline and 14 days post-vaccination. Safety was evaluated by collection of solicited adverse events (AEs) and unsolicited AEs for 7 and 28 days post-vaccination respectively, and SAEs for the entire study period.In total, 18,348 participants were included in the final efficacy and safety analyses. Vaccine efficacy was 42.9 % (95 % CI: −16.1; 71.9) against RSV-associated LRTD with ≥3 symptoms, 59.0 % (95 % CI: 34.7; 74.3) against LRTD with ≥2 symptoms, and 48.8 % (95 % CI: 25.8; 64.7) against ARD. The primary objective was not met for LRTD with ≥3 symptoms since the lower bound of the 95 % CI was below 20 %, the prespecified success criterion. The vaccine-elicited immune response showed mean fold-increases of 1.7 for RSV A and B neutralizing antibodies and 2.9 and 4.3 for RSV-specific IgG and IgA, respectively. The vaccine displayed mild to moderate reactogenicity, and no safety concerns were identified.MVA-BN-RSV induced suboptimal protection against RSV-associated LRTD, likely due to suboptimal neutralizing antibody response. The vaccine had an acceptable safety profile and confirmed immunogenicity, overall showing promise for MVA-BN-vectored constructs targeting other diseases.Trial Registration:Clinicaltrials.gov Identifier NCT05238025 (Registered February 14, 2022).

Excess Cardiopulmonary Arrest and Mortality after COVID-19 Vaccination in King County, Washington

Introduction: Since the onset of widespread COVID-19 vaccination campaigns, there have been concerns about serious cardiovascular adverse events as a result of mass vaccination. This study aimed to estimate excess cardiopulmonary arrest mortality in King County, WA, and investigate any association with COVID-19 vaccination rates. Methods: An exploratory data analysis was performed. Comparative analyses were performed to evaluate the changes in total EMS attendances over time. Excess deaths were calculated using the 2015-2020 cardiopulmonary arrest mortality trend line. The relationship between excess cardiopulmonary arrest mortality and vaccination rates was analyzed using polynomial regression analysis. Results: Approximately 98% of the King County population received at least one dose of a COVID-19 vaccine by 2023. As of August 2nd, 2024, there have been approximately 589,247 confirmed COVID-19 cases in King County. In 2021- 2022, Total EMS attendances in King County sharply increased by 35.34% from 2020 and by 11% from pre-pandemic years. Cases of 'obvious death' upon EMS arrival increased by 19.89% in 2020, 36.57% in 2021, and 53.80% in 2022 compared to the 2017-2019 average. We found a 25.7% increase in total cardiopulmonary arrests and a 25.4% increase in cardiopulmonary arrest mortality from 2020 to 2023 in King County, WA. Excess fatal cardiopulmonary arrests were estimated to have increased by 1,236% from 2020 to 2023, rising from 11 excess deaths (95% CI: -12, 34) in 2020 to 147 excess deaths (95% CI: 123, 170) in 2023. A quadratic increase in excess cardiopulmonary arrest mortality was observed with higher COVID-19 vaccination rates. The general population of King County sharply declined by 0.94% (21,300) in 2021, deviating from the expected population size. Applying our model from these data to the entire United States yielded 49,240 excess fatal cardiopulmonary arrests from 2021-2023. Conclusions: We identified a significant ecological and temporal association between excess fatal cardiopulmonary arrests and the COVID-19 vaccination campaign. The increase in excess cardiopulmonary arrest deaths may also be attributed to COVID-19 infection and disruptions in emergency care during the pandemic. Urgent further research is needed to confirm our observations with attention to risk mitigation for incident events and improved survival with resuscitation.

T Cell Responses to SARS-CoV-2 in Vaccinated Pregnant Women: A Comparative Study of Pre-Pregnancy and During-Pregnancy Infections

The COVID-19 pandemic has posed unprecedented challenges to global public health, particularly for vulnerable populations like pregnant women. This study delves into the T cell immune responses in pregnant women with confirmed SARS-CoV-2 infection, all of whom received three doses of a COVID-19 vaccine. Using the ELISpot assay, we measured T cell responses against SARS-CoV-2 spike S1 and nucleocapsid peptides in two groups: those infected before and during pregnancy. Our results showed weak to moderate correlations between T cell responses and neutralizing antibody levels, with no statistically significant differences between the two groups. T cell reactivity appeared to decrease over time post-diagnosis, regardless of infection timing. Intriguingly, over half of the participants maintained detectable T cell memory responses beyond one year post-infection, suggesting the long-term persistence of cellular immunity. These insights contribute to the understanding of COVID-19 immunology in pregnant women, highlighting the importance of considering both humoral and cellular immune responses in this high-risk population.

Humoral Response to SARS-CoV-2 Vaccine-Boost in Cancer Patients: A Case Series from a Southern European Cancer Center

Background: Cancer patients face a greater risk of complications and death after contracting the SARS-CoV-2 virus. Booster doses of the COVID-19 vaccine were suggested to provide additional protection. This study aimed to assess how cancer patients’ immune systems respond to the booster shots and categorize their responses. Methods: We analyzed 735 samples from 422 individuals, including patients followed at the Portuguese Oncology Institute of Porto (IPO-Porto). Three cohorts were recruited, and blood samples were collected 3- and 6-months post-booster dose: cohort 1 cancer patients (also collected before the booster); cohort 2 cancer patients; and cohort 3 (healthy individuals). Humoral immune response was evaluated by analyzing IgG levels against the SARS-CoV-2 Spike (S) protein. IgG levels against the SARS-CoV-2 Nucleocapsid(N) protein was also analyzed in order to address previous contact with the virus. Results: Among Cohort 1 patients with solid tumors, when compared to pre-boost, IgG S levels increased 3 months after the boost and remained high after 6 months. Patients with hematologic tumors demonstrated lower IgG S levels at both timepoints. Comparing the IgG S levels among hematological tumors, solid tumors, and healthy individuals in both timepoints we observed that the healthy individuals had the strongest IgG S response, followed by the solid, and, lastly, the hematologic tumors. Solid tumor patients undergoing chemotherapy had reduced IgG S levels, especially those on high febrile neutropenia risk regimens. Conclusions: In conclusion, cancer patients have a weaker immune response to the SARS-CoV-2 vaccine, especially those with hematological cancers. Chemotherapy and febrile neutropenia risk further reduce booster effectiveness. Further research is needed to optimize vaccine timing for cancer patients undergoing chemotherapy.

Humoral and cellular response to the third COVID-19 vaccination in patients with inborn errors of immunity or mannose-binding lectin deficiency : Aprospective controlled open-label trial.

Impaired immune response to COVID-19 (coronavirus disease 2019) vaccination has been reported in patients with inborn errors of immunity (IEI). Repetitive vaccinations are recommended for this vulnerable group. Due to the high diversity within IEI patients, additional safety and immunogenicity data are needed to better understand these aspects especially in less common immunodeficiency syndromes. In this prospective open-label clinical trial, we assessed the humoral immune response and the T‑cell response in patients with IEI or severe MBL (mannose-binding lectin) deficiency (IEI/MBLdef) after three vaccinations. A total of 16 patients and 16 matched healthy controls (HC) with suboptimal humoral response defined by anti-SARS-CoV‑2 RBD (severe acute respiratory syndrome coronavirus type 2 receptor binding domain) antibodies below 1500 BAU/ml (binding antibody units per ml) after the second COVID-19 vaccination were enrolled in this study and qualified for athird mRNA vaccine dose. After 4 weeks following vaccination, 100% of HC and 75% of IEI/MBLdef patients exhibited anti-SARS-CoV‑2 RBD antibodies > 1500 BAU/ml, although the difference was not statistically significant (75% vs. 100%; p = 0.109). Although post-vaccination IEI/MBLdef patients demonstrated significantly increased anti-SARS-CoV‑2 RBD antibodies and neutralizing antibodies compared to baseline, these responses were significantly lower in IEI/MBLdef patients compared to HCs. Notably, the third vaccination augmented the cellular immune response to both wild-type and omicron peptide stimulation. No serious adverse events were reported within the 4‑week follow-up period and, importantly, vaccination had little to no effect on the long-term disease activity and fatigue. This trial strongly supports the recommendation of repeated COVID-19vaccinations for patients suffering from immunodeficiencies, especially when they exhibit an initially limited response to the vaccine.

Risk of major adverse cerebro-cardiovascular events following BNT162b2, CoronaVac, and ChAdOx1 vaccination and SARS-CoV-2 infection: A self-controlled case-series study

ObjectiveTo assess the potential risk of major adverse cerebro-cardiovascular events (MACCE) associated with COVID-19 vaccination and SARS-CoV-2 infection. MethodsThis self-controlled case series study used nationwide health database from Malaysia. The study included individuals aged ≥18 years who were hospitalised between 24 February 2021 and 30 June 2022. Outcomes were composite of MACCE: stroke, acute ischaemic heart disease, and cardiovascular death. Exposures were COVID-19 vaccination and SARS-CoV-2 infection. The risk period was day 1 to day 21 following exposure. Conditional Poisson regression model was used to estimate the incidence rate ratios (IRRs) and 95 % confidence interval (CI) comparing the outcomes in the risk and control periods. ResultsThe risk of MACCE within 21 days after vaccination per 100,000 doses administered were 12.0 (95% CI 11.9–12.1) (BNT162b2), 9.2 (95% CI 9.1–9.3) (CoronaVac), and 6.8 (95% CI 6.6–7.0) (ChAdOx1). The incidence rate ratios showed no increased risk of MACCE associated with the first, second, or third doses of BNT162b2, CoronaVac, and ChAdOx1 vaccines for individuals without prior cardiovascular disease (CVD). This finding was consistent for individuals with CVD. Vaccine booster dose, whether in a homologous or heterologous schedule, did not show increased risk of MACCE. Analysis by ethnic groups detected a slightly elevated risk of MACCE in Indian after the first dose of ChAdOx1 (IRR 1.64; 95% CI 1.08–2.48) in those without CVD. No significant association were observed in other subgroup analyses. SARS-CoV-2 infection was associated with significantly increased risk of MACCE in individuals without CVD (IRR 3.54; 95% CI 3.32–3.76) and with CVD (IRR 1.98; 95% CI 1.61–2.34). ConclusionsOur findings support the favourable safety profile of these COVID-19 vaccines and indicate that the overall benefit-risk ratio of the COVID-19 vaccines remains positive.

81 mRNA COVID-19 vaccine safety among children and adolescents from the Canadian National Vaccine Safety Network

Abstract Background The Canadian National Vaccine Safety Network (CANVAS) expanded its active safety surveillance for COVID-19 vaccines among children and adolescents during the COVID-19 pandemic. Objectives This analysis aimed to determine whether the first or second dose of mRNA COVID-19 vaccination is associated with health events in children and adolescents. Design/Methods Adolescents 15-19 years of age or parents/guardians of children 5-14 years of age were recruited from seven Canadian provinces/territories and followed for the occurrence of health events seven days after doses 1 and 2 or for a seven-day period for unvaccinated participants. The primary outcome was a health event that prevented daily activities, resulted in school absenteeism, and/or required a medical consultation, including emergency department visits or hospitalization. Aged-stratified multivariable logistic regression examined health events associated with mRNA COVID-19 vaccines (BNT162b2, mRNA1273, and mixed [different products for doses 1 and 2]) for children aged 5 to 11 years and adolescents aged 12 to 19 years. Results Between January 2021 and February 2023, a total of 249,418 (Children BNT162b2: 205,744, mRNA-1273: 36, and Adolescent BNT162b2: 39,628, mRNA-1273: 4,010) completed the first dose survey and 128,599 (Children BNT162b2: 109,625, mRNA-1273: 3, mixed: 235, and Adolescent BNT162b2: 17,202, mRNA-1273: 1,155, mixed: 474) had completed the second dose survey. A total of 668 unvaccinated participants (Children 431 and Adolescent 237) completed the control survey. In the week following dose 1, health event rates among vaccinated children and adolescents were <4% and lower than in unvaccinated counterparts (6.9%), and neither BNT162b2 nor mRNA-1273 were associated with health events in either age group. Following dose 2, among vaccinated adolescents health events rates (BNT162b2 4.6%, mRNA-1273 8.5%, mixed 10.4%) were higher than unvaccinated adolescents (3.4%), but were self-limiting and resolved within 7 days. Among children, there was no difference in health event rates between vaccinated and unvaccinated groups. Conclusion For children, mRNA COVID-19 vaccines were not associated with health events preventing daily activities, resulting in school absenteeism and/or requiring medical consultation. Similar to vaccinated adults our findings found vaccinated adolescents reported higher rates of health events after dose 2 mRNA COVID-19 vaccines, but these were self-limiting and resolved quickly. Our findings can be used to inform adolescents and their parents of what to expect following COVID-19 vaccination.

Lipschütz ulcer following first dose of COVID-19 tozinameran vaccine: Report of a case and review of a World Health Organization pharmacovigilance database.

Lipschütz ulcer (LU) is a condition known for painful vulvar ulcers, typically affecting young women and often linked to infectious agents. Recent reports have indicated a potential connection between LU and COVID-19 vaccination, particularly after the second or booster doses. This study presents a case of LU following the first dose of tozinameran in a young woman who had a previous SARS-CoV-2 infection and investigates similar cases globally. An 18-year-old woman experienced vulvar pain and ulcers 2-days after her initial COVID-19 vaccine dose. After ruling out infections through serological tests, a diagnosis of LU was made, and her symptoms resolved after 10 days. A literature search and VigiBase® analysis revealed 11 cases of LU following COVID-19 vaccination, and 519 vulvovaginal ulcer cases associated with these vaccines were identified in Vigibase®, with a median onset of 2 days. Most LU cases occurred after the second dose or booster shots. The primary hypothesis for this association is a type 3 hypersensitivity reaction mediated by immune complexes, possibly triggered by prior exposure, as many cases occurred after the second dose. Interestingly, the presented case suggests that prior COVID-19 infection could serve as sensitization. In conclusion, this study highlights the potential occurrence of LU after the initial COVID-19 vaccine dose in young patients with prior COVID-19 infection. While the risk of recurrence after subsequent vaccinations or infections remains uncertain, the benefits of vaccination outweigh the risks. Clinicians and patients should be aware of this potential issue to make informed decisions regarding vaccination.

Health Facility Capacity and Health-care Worker Knowledge, Attitudes, and Practices of Hepatitis B Vaccine Birth-dose and Maternal Tetanus-Diphtheria Vaccine Administration in Nigeria: A Baseline Assessment.

Hepatitis B virus (HBV) and neonatal tetanus infections remain endemic in Nigeria despite the availability of safe, effective vaccines. We aimed to determine health facilities' capacity for hepatitis B vaccine birth dose (HepB-BD) and maternal tetanus-diphtheria (Td) vaccination and to assess knowledge, attitudes, and practices of HepB-BD and maternal Td vaccine administration among health facility staff in Nigeria. This was a cross-sectional study assessing public primary and secondary health facilities in Adamawa and Enugu States. A multistage sampling approach was used to select 40 facilities and 79 health-care workers (HCWs) from each state. A structured facility assessment tool and standardized questionnaire evaluated facility characteristics and HCW knowledge, attitudes, and practices related to HepB-BD and maternal Td vaccination. Frequencies and proportions were reported as descriptive statistics. The survey of 80 facilities revealed that 73.8% implemented HepB-BD and maternal Td vaccination policies. HepB-BD was administered within 24 h of birth at 61.3% of facilities and at all times at 57.5%. However, administration seldom occurred in labor and delivery (35%) or maternity wards (16.3%). Nearly half of the facilities (46.3%) had HCWs believing there were contraindications to HepB-BD vaccination. Among 158 HCWs, 26.5% believed tetanus could be transmitted through unprotected sex, prevented by vaccination at birth (46.1%), or by avoiding sharing food and utensils. 65% of HCWs knew HBV infection had the worst outcome for newborns. The limited implementation of national policies on HepB-BD and maternal Td vaccination, coupled with knowledge gaps among HCWs, pose significant challenges to timely vaccination, necessitating interventions to address these gaps.

Evaluation of the Relationship between Sociodemographic Factors, COVID-19 Fear Levels and Vaccination Status in Patients Applying to Family Medicine Outpatient Clinics in a University Hospital

ABSTRACT Objective: This study has aimed to examine the relationship between sociodemographic factors and COVID-19 fear levels in patients aged 18-65 years and their COVID-19 vaccination status. Methods: The study sample consists of 866 patients aged between 18-65 who applied to the Family Medicine Polyclinics of a university hospital between 01.03.2022 and 01.06.2022. Personal Information Form and Fear of COVID-19 Scale were used to collect data. As the score obtained from the scale increases, the level of fear of COVID-19 increases. The analyzes of the study were done in SPSS 21.0 package program. Kruskal Wallis test and Mann Whitney U test were used for comparisons. Results: 52.3% of the participants in the study were women and the mean age was 36.59±12.32 years. Compared to men, women's fear of coronavirus was statistically significantly higher. The coronavirus fear levels of those who received at least one dose of vaccine compared to those who did not get vaccinated at all, and those who received more doses of vaccines compared to those who received only one dose were found to be statistically significantly higher. Conclusion: As the level of fear of COVID-19 increased, it was determined that the vaccination behavior of individuals was positively affected. COVID-19 is a vaccine preventable disease. With vaccination in all healthcare institutions, it will be possible to prevent morbidity and mortality, as well as economic and social losses that may be caused by the COVID-19 pandemic.

A single immunization of Borreliella burgdorferi-infected mice with Vanguard crLyme elicits robust antibody responses to diverse strains and variants of outer surface protein C.

Lyme disease, caused by Borreliella burgdorferi and related species, is a growing health threat to companion animals across North America and Europe. Vaccination is an important preventive tool used widely in dogs living in, or near, endemic regions. In this report, we assessed anti-outer surface protein (Osp) A and anti-OspC antibody responses in B. burgdorferi-infected and -naïve mice (C3H/HeN) after immunization with a murine-optimized single dose of the Lyme disease subunit vaccine, Vanguard crLyme. crLyme is comprised of OspA and an OspC chimeritope-based immunogen designated as CH14. Mice that were infected and immunized developed higher levels of anti-OspC antibodies (Abs) than those infected only or that received one vaccine dose. The anti-OspC Abs that developed in the infected/immunized mice bound to all OspC variants tested (n = 22), whereas OspC Abs in serum from infected mice bound predominantly to the OspC variant (type A) produced by the infecting B. burgdorferi strain. Consistent with the absence of OspA expression in infected mammals, none of the infected mice developed Abs to OspA and did not develop anti-OspA Abs after single dose immunization. Lastly, serum from infected/immunized mice displayed significantly higher and broader killing activity than serum from non-immunized infected mice. The results of this study demonstrate that a single vaccination of actively infected mice results in strong anti-OspC Ab responses. This study contributes to our understanding of Ab responses to vaccination in actively infected mammals.

Immunogenicity of Comirnaty Omicron XBB.1.5 booster COVID-19 mRNA vaccine in long-term survivors after allogeneic hematopoietic stem cell transplantation

Primary mRNA vaccination against COVID-19 typically involves three doses for immunocompromised individuals, including hematopoietic stem cell transplantation (allo-HSCT) recipients. However, optimal subsequent boosting strategies remain unclear. This study aimed to assess the immunogenicity of a booster dose using the most recently updated vaccine (Comirnaty Omicron XBB.1.5) among long-term allo-HSCT survivors having previously received multiple mRNA vaccine doses, in median 4 (2–6). Thirty-four allo-HSCT recipients were enrolled at Sahlgrenska University Hospital, and peripheral blood samples were collected immediately before and four weeks after booster. Antibodies against the receptor-binding domain (anti-RBD) of spike 1 (S1) and nucleocapsid, as well as S1-specific ex vivo T-cell responses, were evaluated. Adverse events were monitored. Despite a median of 13 months since the prior vaccine dose, both humoral and T-cell responses against S1 were present in the pre-booster samples in all but two participants, who suffered from severe chronic Graft-versus-host disease. Notably, 62% of participants had a previously confirmed COVID-19 infection. Significantly higher pre-booster antibody levels were observed in women than men (p = 0.003). Booster dosing strengthened specific antibody and T cell responses and equalized pre-booster gender differences, although responses remained significantly lower among those receiving immunosuppressive treatment (p = 0.041). In a population of long-term allo-HSCT survivors, the majority of whom had a prior confirmed COVID-19 infection, both pre- and post-booster immune responses were robust. However, patients undergoing immunosuppressive treatment for GvHD exhibited significantly weaker responses.