Determinants of immunization defaulters among children aged 12-23 months in Ambo town, Oromia, Ethiopia: A case-control study

Immunization is a public health intervention to reduce morbidity and mortality among children. However, vaccination becomes more effective if the child can receive the full course of recommended vaccination doses according to the schedule. Many children fail to complete the full course of vaccination. To identify the determinants of immunization defaulters among children aged 12-23 months in Ambo town, Oromia, Ethiopia. A community-based, unmatched, case-control study was done from October 1 to 25, 2021. A simple random sampling was used to select 317 (106 cases and 211 controls). Data were collected by using a pretested and structured questionnaire. Data were coded and entered to Epi-data version 3.1 and then transported to SPSS version 21.0 for statistical analysis. Descriptive analysis like frequency, mean, and percentage was calculated. Binary and multivariable logistic regression analysis was done. Finally, variables with a p value  < .05 were considered statistically significant. Urban residences (AOR = 0.288, 95% CI, 0.146, 570), government employee (AOR = 0.179, 95% CI, 0.057, 0.565), number of family members more than four (AOR = 2.696, 95% CI, 1.143, 6.358), higher income (AOR = 0.250, 95% CI, 0.099, 0.628), attending ANC (AOR = 0..237, 95% CI, 0.107, 0.525), and good awareness (AOR = 0.070, 95% CI, 0.005, 308) were significant predictors of immunization defaulters. This study has found that urban residences, government employee by occupation, number of family members more than four, higher monthly income, and attending ANC were identified as determinants of childhood immunization defaulters. Social Behavior Change intervention programs should focus on providing health information about the importance of the vaccine and vaccine schedule. Due attention should be given for rural residents and farmers who had limited access to information and are more prone to defaulting. Policy-makers should consider those identified factors while designing intervention programs to enhance vaccination coverage.

The urban-poor vaccination: Challenges and strategies in low-and-middle income countries

Vaccination is one of the success stories of public health. The benefit of vaccination goes beyond individual protection to include promoting population well-being, improving cognitive development, and increasing economic productivity. However, the existing inequalities in the access to vaccination undermines its impact. There are significant variations in the coverage of vaccination between and within countries. Despite that urban populations have better access to health services; evidence has shown that the urban poor have the worst health indicators including vaccination uptake. Additionally, there are unique challenges affecting vaccination in urban settings, especially in urban slums. This paper has discussed key challenges some of the proposed interventions that can improve urban vaccination service delivery.

The impact of risk perception and institutional trust on COVID-19 vaccine hesitancy in China

Vaccination has become the primary means for citizens to prevent severe morbidity and mortality during the pandemic. However, vaccine hesitancy poses a major threat to global public health security. Based on the data from Chinese General Social Survey in 2021, this study aims to explore the socio-political aspects of COVID-19 vaccine hesitancy, focusing on the relationship between COVID-19 risk perceptions, institutional trust and vaccine hesitancy. Among the samples, 39.8% of the respondents exhibited COVID-19 vaccine hesitancy, 48.9% had a high awareness of the risk of COVID-19, and 74.6% presented a high level of trust in institutions. The results showed that higher risk perception and institutional trust are negatively correlated with vaccine hesitancy (p < .001). Institutional trust had no statistically significant moderating effect on the association between risk perception and vaccine hesitancy, but the role of institutional trust in influencing vaccine hesitancy is more significant at a lower level of perceptions of COVID-19 risk. Furthermore, regional variations in the factors contributing to vaccine hesitancy were demonstrated in China. These findings have important implications for developing strategies to address vaccine hesitancy.

Impact of COVID-19 vaccination status on hospitalization and disease severity: A descriptive study in Nagasaki Prefecture, Japan

Coronavirus disease 2019 (COVID-19) was extraordinarily harmful, with high rates of infection and hospitalization. This study aimed to evaluate the impact of COVID-19 vaccination status and other factors on hospitalization and disease severity, using data from Nagasaki Prefecture, Japan. Confirmed cases of COVID-19 infection with vaccination status were included and the differences in characteristics between different vaccination statuses, hospitalization or not, and patients with varying levels of disease severity were analyzed. Furthermore, logistic regression was used to calculate odds ratio (ORs) and 95% confidence intervals (CI) to evaluate the association of various factors with hospitalization and disease severity. From March 14, 2020 to August 31, 2022, 23,139 patients were unvaccinated 13,668 vaccinated the primary program with one or two doses, and 4,575 completed the booster. Vaccination reduced the risk of hospitalization with an odd ratio of 0.759 (95% CI: 0.654-0.881) and the protective effect of completed booster vaccination was more pronounced (OR: 0.261, 95% CI: 0.207-0.328). Similarly, vaccination significantly reduced the risk of disease severity (vaccinated primary program: OR: 0.191, 95% CI: 0.160-0.228; completed booster vaccination: OR: 0.129, 95% CI: 0.099-0.169). Overall, unvaccinated, male, elderly, immunocompromised, obese, and patients with other severe illness factors were all risk factors for COVID-19-related hospitalization and disease severity. Vaccination was associated with a decreased risk of hospitalization and disease severity, and highlighted the benefits of completing booster.

Expanded spectrum of varicella disease and the need for vaccination in India

Varicella vaccine was first licensed in Japan and South Korea in 1989 for use in healthy children and was introduced in US in 1995. So far, 29 countries have adopted varicella vaccine in their universal immunization program (UIP). No Asian country, India included, has adopted the varicella vaccine as part of their UIP. The extra-cutaneous sites for VZV diseases are central nervous system and gastrointestinal tract, the expanded disease spectrum includes vasculopathy, myelitis, inflammatory bowel disease, perforated ulcers, and gastritis. The actual disease burden of varicella is not known as most of the infected individuals may not visit the physician. The amplifiable VZV DNA will not always be detectable in cerebrospinal fluid (CSF) samples in protracted illnesses such as vasculopathies, but demonstrable anti-VZV IgG in CSF has diagnostic value. The World Health Organization (WHO) position paper 2014 recommends two doses of varicella and zoster vaccines in targeted population. In India, varicella vaccine is not included in the UIP due to the cost and the belief that lifelong immunity occurs following primary infection. The expanded spectrum of VZV disease and the mounting body of evidence, however, suggest the need for both varicella and zoster vaccines in routine immunization schedule.

Using big data to analyze the vaccination status of children with congenital heart disease in Yinzhou District, China

Congenital heart disease (CHD) represents a significant population warranting particular attention concerning vaccination coverage. To comprehend the vaccination status of CHD within Yinzhou District, Ningbo City, China, and to facilitate the formulation of preventive, control, and immunization strategies against vaccine-preventable diseases in children with congenital heart conditions. Using the China Yinzhou Electronic Health Record Study (CHERRY) database, we analyzed the vaccination coverage of children with CHD born between January 1, 2016 and September 20, 2021, and analyzed the influencing factors associated with the level of vaccination coverage. This study involved 762 children diagnosed with CHD at the age of 12 months, revealing that 86.74% of these children had received at least one dose of the National Immunization Program (NIP) vaccines. The coverage for non-NIP vaccines, such as the rotavirus vaccine, influenza vaccine, Influenza Haemophilus influenzae Type b (Hib) Conjugate Vaccine, 13-valent pneumococcal conjugate vaccine (PCV13), and inactivated enterovirus type 71 vaccine (EV71), stood at 27.30%, 7.74%, 63.25%, 33.76%, and 34.51%, respectively. The completion coverage for the entire vaccination schedule were 27.30%, 5.51%, 55.77%, 34.25%, and 25.59%, respectively. There was a statistically significant correlation between vaccination coverage in classification of diagnostic medical institutions and the types of diagnosed diseases. Compared to their typically developing counterparts, 12-month-old children afflicted with CHD exhibit a slightly diminished vaccination coverage, alongside a discernible inclination toward delayed vaccination. Notably, the determination to undergo vaccinations seems predominantly influenced by the classification of diagnostic medical institutions. In practical terms, proactive measures involving early diagnosis, comprehensive health assessments, and timely interventions ought to be implemented to enhance vaccination rates while prioritizing safety.

COVID-19 vaccine hesitancy among the Chinese elderly: A multi-stakeholder qualitative study

The United Nations reported that the mortality risk of Corona Virus Disease 2019 (COVID-19) is five times higher in the elderly than the global average. Although the COVID-19 vaccine effectively prevents infections and reduce mortality among the elderly, vaccine hesitancy among the Chinese elderly poses a significant threat. This study, utilizing the "Confidence, Convenience and Complacency (3 Cs)" vaccine hesitancy model, aimed to explore factors contributing to vaccine hesitancy among the Chinese elderly and assess national countermeasures and potential improvement approaches. Thirteen elderly with vaccine hesitancy and eleven vaccine-related staff participated in semi-structured interviews. Thematic analysis revealed three key determinants of vaccine hesitancy among the elderly: perceived low threat of COVID-19, lack of confidence in COVID-19 vaccine, and poor accessibility to vaccination. China has implemented strategies, including advocacy through diverse channels, joint multi-sectoral promotion vaccination, and enhancing ongoing vaccination services. Recommendations from the vaccine-related staff emphasize improving vaccine awareness among the elderly, and prioritizing the vaccination environment and process. The study underscores the importance of targeted vaccination promotion programs addressing hesitation reasons to improve vaccination rates. Furthermore, existing countermeasures can serve as a foundation for enhancing vaccination strategies, including improved publicity, administration, and management approaches.

"Going vaccine hunting": Multilevel influences on COVID-19 vaccination among racialized sexual and gender minority adults-a qualitative study

High levels of COVID-19 vaccine hesitancy have been reported among Black and Latinx populations, with lower vaccination coverage among racialized versus White sexual and gender minorities. We examined multilevel contexts that influence COVID-19 vaccine uptake, barriers to vaccination, and vaccine hesitancy among predominantly racialized sexual and gender minority individuals. Semi-structured online interviews explored perspectives and experiences around COVID-19 vaccination. Interviews were recorded, transcribed, uploaded into ATLAS.ti, and reviewed using thematic analysis. Among 40 participants (mean age, 29.0 years [SD, 9.6]), all identified as sexual and/or gender minority, 82.5% of whom were racialized. COVID-19 vaccination experiences were dominated by structural barriers: systemic racism, transphobia and homophobia in healthcare and government/public health institutions; limited availability of vaccination/appointments in vulnerable neighborhoods; absence of culturally-tailored and multi-language information; lack of digital/internet access; and prohibitive indirect costs of vaccination. Vaccine hesitancy reflected in uncertainties about a novel vaccine amid conflicting information and institutional mistrust was integrally linked to structural factors. Findings suggest that the uncritical application of "vaccine hesitancy" to unilaterally explain undervaccination among marginalized populations risks conflating structural and institutional barriers with individual-level psychological factors, in effect placing the onus on those most disenfranchised to overcome societal and institutional processes of marginalization. Rather, disaggregating structural determinants of vaccination availability, access, and institutional stigma and mistrust from individual attitudes and decision-making that reflect vaccine hesitancy, may support 1) evidence-informed interventions to mitigate structural barriers in access to vaccination, and 2) culturally-informed approaches to address decisional ambivalence in the context of structural homophobia, transphobia, and racism.

Neutralizing antibody titers over 12 months after SARS-CoV-2 mRNA vaccine booster in patients with relapsing multiple sclerosis continuously treated with ofatumumab

Booster vaccinations against SARS-CoV-2 are recommended 6-12 months after the last dose or infection in elderly and high-risk groups. The present analysis aims to evaluate whether an interval shorter than 12 months is required in multiple sclerosis patients receiving ofatumumab. Neutralizing antibody status over 1 year in patients receiving booster vaccination in the non-interventional, multicenter KYRIOS study under continued ofatumumab treatment was analyzed. Fifteen patients were included. At the time of the first booster vaccination, ten patients were seropositive for neutralizing antibodies, four patients were seronegative, and for one patient, no baseline levels were available. All patients who were seropositive at baseline showed >2-fold increase in neutralizing antibody titers after the first booster and two patients (20%) showed a >10-fold increase. Among seronegative patients, three (75%) had a >10-fold increase in neutralizing antibody titers. Seropositivity was maintained in almost all patients until month 12. One initially seronegative patient had less than 2-fold increase in neutralizing antibody titers after the booster vaccination and can be considered a non-responder. Most patients with continued ofatumumab treatment are able to maintain permanent seropositivity and therefore presumably constant protection against severe courses of COVID-19 if repeated booster vaccinations are applied.

Comparative immunogenicity and neutralizing antibody responses post heterologous vaccination with CoronaVac (Sinovac) and Vaxzevria (AstraZeneca) in HIV-infected patients with varying CD4+ T lymphocyte counts

The immune response to heterologous coronavirus disease (COVID-19) vaccination in people living with HIV (PLWH) is still unclear. Herein, our prospective cohort study aimed to compare the immune response of heterologous vaccination with CoronaVac (Sinovac) and Vaxzevria (AstraZeneca) between PLWH having CD4 counts ≤ 200 cells/µL (low CD4+) and > 200 cells/µL (high CD4+). Anti-receptor-binding domain (RBD) immunoglobulin G (IgG) levels and the percentage inhibition of neutralizing antibodies (nAbs) were analyzed at 2 and 12 weeks after immunization. Participants in the low and high CD4+ groups had mean CD4+ counts of 139 and 575 cell/µL, respectively. Two and 12 weeks after immunization, in the low CD4 group, the median anti-RBD-IgG levels were 159 IU/mL and 143 IU/mL, respectively, whereas the nAb level was 71% and decreased to 47.2%, respectively. Contrarily, the median anti-RBD-IgG levels in the high CD4+ group were 273 IU/mL and 294 IU/mL, respectively, whereas the nAb levels were 89.3% and relatively stable at 81.6%. However, although immune responses between the two study groups were not significantly different, a decline in nAb levels was observed at 12 weeks in the low CD4+ group. Therefore, a COVID-19 booster vaccine dose is suggested for immunoprotection.

Human papillomavirus vaccination uptake and determinant factors among adolescent schoolgirls in sub-Saharan Africa: A systematic review and meta-analysis

Despite the ongoing global vaccination campaign aimed at preventing human papillomavirus (HPV) related health issues, the uptake of the HPV vaccine remains unacceptably low in developing regions, particularly in sub-Saharan Africa (SSA). Therefore, this systematic review and meta-analysis aimed at determining the pooled prevalence and associated factors of HPV vaccine uptake among adolescent school girls in SSA. Electronic bio-medical databases were explored. Pooled prevalence, publication bias, meta-regression, sub-group, and sensitivity analysis were performed. The estimated pooled prevalence of HPV vaccine uptake was 28.53% [95% CI: (5.25, 51.81)]. Having good knowledge and a positive attitude was significantly associated with HPV vaccine uptake in SSA. Subgroup analysis revealed the highest uptake was 62.52% from Kenya and the lowest was 3.77% in Nigeria. The HPV vaccine uptake is low. It underscores the need for community education, school-based immunization, and education programs that promote the uptake of the vaccine to increase coverage.

Prevention of bleomycin-induced pulmonary fibrosis by vaccination with the Tocilizumab mimotope

Mimotope, a kind of peptide vaccine, is developed to bind natural receptor and inhibit the downstream signaling. We have demonstrated that the vaccination of Tocilizumab mimotopes could alleviate the renal fibrosis by interfering with both IL-6 and ferroptosis signaling. However, the effect of the vaccination of Tocilizumab mimotopes on the fibroblast was not investigated in previous study. Thus, we sought to explore the changes in the fibroblast induced by the Tocilizumab mimotopes vaccination. Bleomycin instillation was performed to construct the pulmonary fibrosis model after the immunization of Tocilizumab mimotopes. Lung histological analysis showed that the Tocilizumab mimotopes could significantly reduce the maladaptive repairment and abnormal remodeling. Immunoblotting assay and fluorescence staining showed that Immunization with the Tocilizumab mimotopes reduces the accumulation of fibrosis-related proteins. High level of lipid peroxidation product was observed in the animal model, while the Tocilizumab mimotopes vaccination could reduce the generation of lipid peroxidation product. Mechanism analysis further showed that Nrf-2 signaling, but not GPX-4 and FSP-1 signaling, was upregulated, and reduced the lipid peroxidation. Our results revealed that in the BLM-induced pulmonary fibrosis, high level of lipid peroxidation product was significantly accumulation in the lung tissues, which might lead to the occurrence of ferroptosis. The IL-6 pathway block therapy could inhibit lipid peroxidation product generation in the lung tissues by upregulating the Nrf-2 signaling, and further alleviate the pulmonary fibrosis.

Perceived impact of discussions with a healthcare professional on patients' decision regarding COVID-19 vaccine

There is evidence that advice from Healthcare Professionals (HCPs) plays an important role in patients' decision to get vaccinated, but the extent to which patients perceive this impact is unclear. The aim of this study was to assess the perceived impact of a discussion with a HCP on participants' decision to be vaccinated against COVID-19. A cross-sectional survey was conducted among adults who consulted a general practitioner (GP) or a pharmacist in Ile-de-France, France, after COVID-19 vaccines became available (October-November 2021 period). A total of 344 participants were included, 65.2% of whom reported having had a discussion about COVID-19 vaccines with a HCP. Overall, 55% of participants were advised to be vaccinated by their HCP. Most of the discussions took place with a GP (n = 203, 48.9%). According to 52.5% of participants, the discussion had a positive impact, i.e. it was perceived as encouraging vaccination. The latter reported that, among HCPs, GPs had the greatest number of discussions with a positive impact on the decision to be vaccinated against COVID-19 (93.1%). In the study population, the COVID-19 vaccine hesitancy rate, according to the WHO definition, was high (38.1%), although the COVID-19 vaccine coverage rate was 87.1%. Vaccine hesitant participants were more likely to report a discussion that had a perceived negative impact on their decision to get vaccinated (20.0%) than non-hesitant participants (5.8%, p = .004).

Performance evaluation on vaccination rates monitoring report system of Shenzhen, China

To evaluate the performance of "Vaccination Rates Monitoring Report System" implemented by Shenzhen CDC, we conducted an analysis of the data quality and identify key areas for system improvement. Following evaluation guidelines provided by WHO and United States CDC, we established six evaluation attributes: representativeness, simplicity, acceptability, data reliability, stability and timeliness. In eastern, central and western regions of Shenzhen, we selected one district from each region, of which the local CDC and ten CHSCs under jurisdiction were chosen for evaluation. On-site inspections, questionnaires survey and interviews were utilized for data collection, while the Likert scale method was used for attributes rating evaluation. A total of 70 participants were surveyed, consisting of 60 CHSCs and 10 CDCs staff. The gender ratio was 1:2.5 (males to females), with the majority falling within the 25-34 age range (46%). Most participants held full-time positions (80%) and had more than 5 years of work experience (62%). The system achieved 100% coverage of all CHSCs and CDCs (100%). The cumulative percentage scores for the overall favorable options of simplicity, acceptability, data reliability, stability, and timeliness were 79%, 85%, 73%, 50%, and 71% respectively. The system operates normally with strong representativeness. Acceptability was rated as "good." Simplicity, data reliability, and system timeliness were rated as "average," while system stability was rated as "poor." Based on these survey results, developers should urgently investigate reasons for poor stability, particularly addressing concerns from CHSCs users. Additionally, the issues and shortcomings identified in other attributes should also be gradually improved.

Parents and teachers' perspectives on a school-located influenza vaccination program: A pilot study in the Region of Murcia, Spain

During the 2022-2023 season, the Region of Murcia (an autonomous community of Spain) introduced the influenza vaccination campaign in children aged 24-59 months with the live-attenuated influenza nasal spray vaccine. To expand coverage, a pilot study was conducted to include the 3- to 4-year population in 24 public schools. The aim of the study was to assess the experiences of parents and teachers involved in the project. This was a psychosocial qualitative study in which information was collected from a cohort of 23 parents and 17 teachers who attended three and two focus group sessions, respectively. A high degree of satisfaction with the school-located influenza vaccination program was consistently reported. The teachers reported creating a friendly environment and acting as companions to support children in the absence of their parents. They also considered the intranasal route, which avoids intramuscular puncture, as a facilitating element that turned the vaccination process into a kind of game. Parents emphasized the importance of vaccination to protect their children, and secondarily, to ensure protection of the family nucleus. Some parents who had their children already vaccinated in the health care center reported preference for the school setting, probably selecting this option in the future. The availability of school-based influenza vaccination promoted greater equity in accessing the vaccine and facilitated family reconciliation. To optimize coverage and minimize potential reluctance, providing the necessary information to parents both before and after vaccination was considered. School-located influenza vaccination was feasible and is a valuable strategy to be implemented in future campaigns.

"The needle is already ready to go": communities' and health care professionals' perceptions of routine vaccination in Nunavik, Canada

Inuit living in the northern region of Nunavik continue to experience significant health inequalities, which are rooted in colonialism that still have repercussions on their health-related perceptions and practices, including vaccination. This study aimed to explore the perceptions and determinants of routine vaccination among the Inuit of Nunavik by describing factors influencing vaccination decisions from the perspective of community members and health professionals. Semi-structured interviews focusing on the perception of vaccination and experience with vaccination and health services were conducted with 18 Inuit and 11 non-Inuit health professionals. Using the socio-ecological model, factors acting at the community and public policy (e.g. rumours and misinformation about vaccination, language barrier), organisational (e.g. complexity of the vaccination process, staff turnover, lack of specialised vaccination workers and interpreters), and intrapersonal and interpersonal (e.g. past experiences with vaccination, vaccine attitudes, social norms) levels were identified as having an impact on vaccination decisions. Improving vaccination coverage in Nunavik requires a more global reflection on how to improve and culturally adapt the health care and services offered to the Inuit population.

Immunogenicity and protective efficacy of inactivated coxsackievirus B4 viral particles

Coxsackievirus B4 (CVB4) is associated with a range of acute and chronic diseases such as hand, foot, and mouth disease, myocarditis, meningitis, pancreatitis, and type 1 diabetes, affecting millions of young children annually around the world. However, no vaccine is currently available for preventing CVB4 infection. Here, we report the development of inactivated viral particle vaccines for CVB4. Two types of inactivated CVB4 particles were prepared from CVB4-infected cell cultures as vaccine antigens, including F-particle (also called mature virion) consisting of VP1, VP3, VP2, and VP4 subunit proteins, and E-particle (also called empty capsid) which is made of VP1, VP3, and uncleaved VP0. Both the inactivated CVB4 F-particle and E-particle were able to potently elicit neutralizing antibodies in mice, despite slightly lower neutralizing antibody titres seen with the E-particle vaccine after the third immunization. Importantly, we demonstrated that passive transfer of either anti-F-particle or anti-E-particle sera could completely protect the recipient mice from lethal CVB4 challenge. Our study not only defines the immunogenicity and protective efficacy of inactivated CVB4 F-particle and E-particle but also reveals the central role of neutralizing antibodies in anti-CVB4 protective immunity, thus providing important information that may accelerate the development of inactivated CVB4 vaccines.

Perspectives on AI-based recommendations for mask-wearing and COVID-19 vaccination for transplant recipients in the post-COVID-19 era

In the aftermath of the COVID-19 pandemic, the ongoing necessity for preventive measures such as mask-wearing and vaccination remains particularly critical for organ transplant recipients, a group highly susceptible to infections due to immunosuppressive therapy. Given that many individuals nowadays increasingly utilize Artificial Intelligence (AI), understanding AI perspectives is important. Thus, this study utilizes AI, specifically ChatGPT 4.0, to assess its perspectives in offering precise health recommendations for mask-wearing and COVID-19 vaccination tailored to this vulnerable population. Through a series of scenarios reflecting diverse environmental settings and health statuses in December 2023, we evaluated the AI's responses to gauge its precision, adaptability, and potential biases in advising high-risk patient groups. Our findings reveal that ChatGPT 4.0 consistently recommends mask-wearing in crowded and indoor environments for transplant recipients, underscoring their elevated risk. In contrast, for settings with fewer transmission risks, such as outdoor areas where social distancing is possible, the AI suggests that mask-wearing might be less imperative. Regarding vaccination guidance, the AI strongly advocates for the COVID-19 vaccine across most scenarios for kidney transplant recipients. However, it recommends a personalized consultation with healthcare providers in cases where patients express concerns about vaccine-related side effects, demonstrating an ability to adapt recommendations based on individual health considerations. While this study provides valuable insights into the current AI perspective on these important topics, it is crucial to note that the findings do not directly reflect or influence health policy. Nevertheless, given the increasing utilization of AI in various domains, understanding AI's viewpoints on such critical matters is essential for informed decision-making and future research.

Concomitant administration of seasonal influenza and COVID-19 mRNA vaccines

Current clinical guidelines support the concomitant administration of seasonal influenza vaccines and COVID-19 mRNA boosters vaccine. Whether dual vaccination may impact vaccine immunogenicity due to an interference between influenza or SARS-CoV-2 antigens is unknown. We aimed to understand the impact of mRNA COVID-19 vaccines administered concomitantly on the immune response to influenza vaccines. For this, 128 volunteers were vaccinated during the 22-23 influenza season. Three groups of vaccination were assembled: FLU vaccine only (46, 35%) versus volunteers that received the mRNA bivalent COVID-19 vaccines concomitantly to seasonal influenza vaccines, FluCOVID vaccine in the same arm (42, 33%) or different arm (40, 31%), respectively. Sera and whole blood were obtained the day of vaccination, +7, and +28 days after for antibody and T cells response quantification. As expected, side effects were increased in individuals who received the FluCOVID vaccine as compared to FLU vaccine only based on the known reactogenicity of mRNA vaccines. In general, antibody levels were high at 4 weeks post-vaccination and differences were found only for the H3N2 virus when administered in different arms compared to the other groups at day 28 post-vaccination. Additionally, our data showed that subjects that received the FluCOVID vaccine in different arm tended to have better antibody induction than those receiving FLU vaccines for H3N2 virus in the absence of pre-existing immunity. Furthermore, no notable differences in the influenza-specific cellular immune response were found for any of the vaccination groups. Our data supports the concomitant administration of seasonal influenza and mRNA COVID-19 vaccines.

Investigating the impact of vaccine hesitancy on an emerging infectious disease: a mathematical and numerical analysis

Throughout the last two centuries, vaccines have been helpful in mitigating numerous epidemic diseases. However, vaccine hesitancy has been identified as a substantial obstacle in healthcare management. We examined the epidemiological dynamics of an emerging infection under vaccination using an SVEIR model with differential morbidity. We mathematically analyzed the model, derived R 0 , and provided a complete analysis of the bifurcation at R 0 = 1 . Sensitivity analysis and numerical simulations were used to quantify the tradeoffs between vaccine efficacy and vaccine hesitancy on reducing the disease burden. Our results indicated that if the percentage of the population hesitant about taking the vaccine is 10%, then a vaccine with 94% efficacy is required to reduce the peak of infections by 40%. If 60% of the population is reluctant about being vaccinated, then even a perfect vaccine will not be able to reduce the peak of infections by 40%.

Humoral responses to multiple SARS-CoV-2 variants after two doses of vaccine in kidney transplant patients

Background: The COVID-19 pandemic has led to millions of fatalities globally. Kidney transplant (KT) patients, given their comorbidities and under immunosuppressant drugs, are identified as a high-risk group. Though vaccination remains pivotal for pandemic control, some studies indicate that KT exhibits diminished immune reactions to SARS-CoV-2 vaccines. Therefore, evaluating the vaccine responses in KT, especially the humoral responses against emergent variants is crucial.Methods: We developed a multiplexed SARS-CoV-2 variant protein microarray, incorporating the extracellular domain (ECD) and the receptor binding domain (RBD) of the spike proteins from the variants. This was employed to investigate the collective humoral responses after administering two doses of mRNA-1273 and AZD1222 vaccines in KT under immunosuppressive drugs and in healthy controls.Results: After two doses of either mRNA-1273 or AZD1222, the KT generally showed lower surrogate neutralizing and total antibodies against spike ECD in multiple variants compared to healthy controls. Although two doses of mRNA-1273 induced 1.5-2 fold more surrogate neutralizing and total antibodies than AZD1222 in healthy controls, the KT subjects with two doses of mRNA-1273 generally exhibited higher surrogate neutralizing but similar total antibodies against spike ECD in multiple variants. There were moderate to high correlations between the surrogate neutralizing and total antibodies against spike ECDs.Conclusion: This study offers pivotal insights into the relative vulnerability of KT concerning humoral immunity and the evolving mutations of SARS-CoV-2. Such findings are useful for evaluating vaccine responses and recommending vaccine episodes for KT.

The characterization of CD8+ T-cell responses in COVID-19

This review gives an overview of the protective role of CD8+ T cells in SARS-CoV-2 infection. The cross-reactive responses intermediated by CD8+ T cells in unexposed cohorts are described. Additionally, the relevance of resident CD8+ T cells in the upper and lower airway during infection and CD8+ T-cell responses following vaccination are discussed, including recent worrisome breakthrough infections and variants of concerns (VOCs). Lastly, we explain the correlation between CD8+ T cells and COVID-19 severity. This review aids in a deeper comprehension of the association between CD8+ T cells and SARS-CoV-2 and broadens a vision for future exploration.