Dose Of Vaccine Research Articles

Messaging to Reduce Booster Hesitancy among the Fully Vaccinated.

Vaccine hesitancy was a serious problem in the United States throughout the COVID-19 pandemic, due in part to the reduction in public trust in science that accompanied the pandemic. Now we are facing a new, similar but more extensive problem: booster hesitancy. Even fewer Americans are current on the mRNA booster. We present the results of an experiment with residents of the US who received all initial doses of the mRNA vaccine but who were not up to date on the booster. Participants read a scientific explanation describing either the safety or the effectiveness of the boosters or nothing in the control group. The explanations significantly increased (compared to the control) participants' perceptions of the safety and effectiveness of the mRNA booster, as well as their willingness to get boosted. Explanations also improved emotions and attitudes toward the booster. Furthermore, although liberals were significantly more willing to get boosted than were conservatives, improvement due to the explanations was similar across political ideology groups. However, when interactions were observed, conservatives increased to a greater degree. Importantly, the explanations increased participants' perception of scientists' expertise and knowledge, as well as participants' trust in scientists and the vaccine technology.

A single dose of an ALVAC vector-based RABV virus-like particle candidate vaccine induces a potent immune response in mice, cats and dogs

Rabies, caused by the Rabies virus (RABV), is a highly fatal zoonotic disease. Existing rabies vaccines have demonstrated good immune efficacy, but the complexity of immunization procedures and high cost has impeded the elimination of RABV, particularly in the post-COVID-19 era. There is a pressing need for safer and more effective rabies vaccines that streamline vaccination protocols and reduce expense. To meet this need, we have developed a potential rabies vaccine candidate called ALVAC-RABV-VLP, utilizing CRISPR/Cas9 gene editing technology. This vaccine employs a canarypox virus vector (ALVAC) to generate RABV virus-like particles (VLPs). In mice, a single dose of ALVAC-RABV-VLP effectively activated dendritic cells (DCs), follicular helper T cells (Tfh), and the germinal center (GC)/plasma cell axis, resulting in durable and effective humoral immune responses. The survival rate of mice challenged with lethal RABV was 100%. Similarly, in dogs and cats, a single immunization with ALVAC-RABV-VLP elicited a stronger and longer-lasting antibody response. ALVAC-RABV-VLP induced superior cellular and humoral immunity in both mice and beagles compared to the commercial inactivated rabies vaccine. In conclusion, ALVAC-RABV-VLP induced robust protective immune responses in mice, dogs and cats, offering a novel, cost-effective, efficient, and promising approach for herd prevention of rabies.

Indirect effectiveness of COVID-19 vaccines in the pre-omicron and omicron periods: A nation-wide test-negative case-control study in Brazil

ObjectivesMass COVID-19 immunization campaigns altered the pandemic's progress by protecting the vaccine recipient and reducing transmission. However, evidence for indirect vaccine effectiveness (IVE) is limited due to the difficulties of ascertaining this type of protection. MethodsUsing linked national Brazilian databases, we adapted the test-negative design to evaluate the IVE against symptomatic infection. We analyzed data from January 1 to December 1, 2021 (pre-omicron) and January 1 to April 30, 2022 (omicron BA.1 and BA.2). We compared the probability of testing positive across various levels of second ancestral-strain monovalent COVID-19 vaccine dose coverage, including only unvaccinated individuals in the main analysis and both vaccinated and unvaccinated individuals in additional analyses. Sensitivity analysis focused on children younger than 12 years who did not have access to COVID-19 vaccines during the pre-omicron period. ResultsWe included 11,039,315 unvaccinated individuals tested during the pre-omicron study period. IVE was minimal until 30% vaccination coverage (<10%), then it followed a dose-dependent pattern, peaking at 37.7 (95% confidence interval 32-42.8) at 70% coverage. For children younger than 12 years, IVE peaked at 59.8% (95% confidence interval 52.7-65.9) at 70% coverage. During the omicron period, IVE remained constant at about 5% across all comparisons. ConclusionsOur findings confirm that high vaccination coverage using vaccines that prevent infection indirectly protects the community. However, IVE was substantially higher during the pre-omicron period.

COVID-19 vaccine uptake in individuals with functional difficulty, disability, and comorbid conditions: insights from a national survey in Bangladesh

BackgroundCOVID-19 vaccine uptake among individuals with disabilities is crucial for safeguarding their health and well-being. However, the extent of vaccine uptake among this group remains largely unknown in low- and middle-income countries. This study aims to assess the COVID-19 vaccine uptake among persons with functional difficulty, disability and/or comorbidity in Bangladesh and their associated factors.MethodsData from 9,370 respondents extracted from the 2021 National Household Survey on Persons with Disability were analysed. The outcome variable was the uptake of at least one dose of the COVID-19 vaccine (yes, no). Key explanatory variables included the presence of disability (yes, no), comorbidity (yes, no), and both comorbidity and disability (yes, no) among persons with functional difficulty. The relationship between the outcome and explanatory variables was determined using mixed-effects multilevel logistic regressions adjusted for covariates.ResultsThe overall uptake of at least one dose of the COVID-19 vaccine among persons with functional difficulty was 57.37%, among persons with functional difficulty and disability was 48.63% and among persons with functional difficulty and single (57.85%) or multi-comorbidity (60.37%). Compared to the respondents with functional difficulty only, the adjusted odds ratio (aOR) of not receiving any dose of the COVID-19 vaccine for individuals with both functional difficulty and disability was 1.37 (95% CI, 1.22–1.53), and for individuals with functional difficulty, disability and one or more comorbid conditions was 1.30 (95% CI, 1.15–1.47). The aOR of receiving at least one dose of the COVID-19 vaccine among individuals with functional difficulty and one or more comorbid conditions was significantly higher than among those with functional difficulty only.ConclusionIn Bangladesh, COVID-19 vaccine uptake was relatively low among individuals with disabilities. The existing COVID-19 vaccine rollout programs and similar future programs should prioritise individuals with disabilities and include targeted strategies to reach them.

Infectious diseases and global security: Analysis of global control and vaccination strategies

Introduction: Given the recent experience with the COVID-19 vaccine campaign, an optimal global policy to control future pandemics and ensure infectious security globally is highly relevant. Objective: The study aims to determine the optimal vaccination strategy to reduce COVID-19 morbidity and mortality during a pandemic.Methods: A systematic search of studies on infectious disease control and vaccination strategies for the period 2000-2023 in PubMed, Scopus, Web of Science and Google Scholar databases using keywords was conducted for the review. Relevant publications, data extraction and systematisation were selected.Results: The findings of the analysis highlight the importance of integrated interventions in global vaccination strategies, including health systems strengthening, innovative technologies for outbreak detection and international collaboration. Vaccination, as an effective preventive measure, significantly reduces the spread of infectious diseases. Vaccination with different types of vaccines has been shown to improve immune response compared to the use of the same type of vaccine. This approach, where the first and second vaccine doses are different, may increase the effectiveness of the immune response.Conclusions: Studies confirm that vaccination reduces the number of cases and deaths, reducing the economic burden. A variety of vaccines, including mRNA, vector, and inactivated vaccines, provide high efficacy in preventing COVID-19 infection and mortality, especially when a heterologous vaccination regimen is used. This review identifies the most effective infectious disease control strategies for the development of global health recommendations

Development of novel multi-protein chimeric immunogens that protect against infection with the Lyme disease agent, Borreliella burgdorferi.

Lyme disease is the most common tick-borne disease in North America. A vaccine for use in humans is not available. Here, we detail the development of two chimeric vaccine antigens, BAF and Chv2M. BAF elicits Abs that target proteins and protein variants produced by Borreliella species in ticks (OspB and OspA) and mammals (FtlA/B). OspB serves as the backbone structure for the BAF chimeric. Two OspA221-240 epitope-containing domain (ECD) variants (#A1 and #A15) were inserted into a loop in OspB. The N-terminal region of the FtlA protein was joined to the C-terminus of the chimeric. The second chimeric, Chv2M, consists of L5 (loop 5) and H5 (helix 5) ECDs derived from diverse OspC proteins. Borreliella species produce OspC upon exposure to the bloodmeal and during early infection in mammals. Here, we demonstrate that BAF and Chv2M are potent immunogens that elicit Abs that bind to each component protein (FtlA, FtlB, OspB, and multiple OspA and OspC variants). Anti-BAF and anti-Chv2M Abs kill Borreliella burgdorferi strains through Ab-mediated complement-dependent and complement-independent mechanisms. Eighty percent (32/40) of mice that received a three-dose vaccine regimen were protected from infection with B. burgdorferi B31. Efficacy increased to 90% (18/20) when the amount of Chv2M was increased in the third vaccine dose. Readouts for infection were flaB PCR and seroconversion to VlsE. This study establishes proof of principle for a chimeric immunogen vaccine formulation that elicits Abs to multiple targets on the B. burgdorferi cell surface produced during tick and mammalian stages of the enzootic cycle.IMPORTANCELyme disease is a growing public health threat across parts of the Northern Hemisphere. Regions that can support sustained tick populations are expanding, and the incidence of tick-borne diseases is increasing. In light of the increasing risk of Lyme disease, effective preventive strategies are needed. Most vaccine development efforts have focused on outer surface protein A, a Borreliella burgdorferi protein produced only in ticks. Herein, we describe the development of a novel vaccine formulation consisting of two multivalent chimeric proteins that are immunogenic and elicit antibodies with bactericidal activity that target several cell surface proteins produced by the Lyme disease spirochetes in feeding ticks and mammals. In a broader sense, this study advances efforts to develop custom-designed vaccinogens comprised of epitope-containing domains from multiple proteins.

Local and systemic side effects of COVID-19 vaccine in Tunisian cancer patients: A prospective single center study.

We aimed to evaluate the local and systemic side effects of the COVID-19 vaccine in cancer patients. we conducted a cross-sectional study including cancer patients treated at Habib Bourguiba Hospital in Sfax, Tunisia between January and March 2022. Patients should have received at least 1 dose of a COVID-19 vaccine. We interviewed a total of 106 patients, of which 80.2% were actively treated. Mean age was 52.52. Patients were vaccinated by the Pfizer/BioNTech in 59.8% and the Oxford/AstraZeneca in 22.5%. The most frequent grade 1 or 2 adverse events occurring within 7 days were: pain at injection site (71.7%) and fatigue (38.7%). Only 2 patients developed grade 3 toxicity following vaccination. The most systemic side effects were fatigue (35.8%), fever (25.4%), headache (16.9%) and arthralgia (15.1%). They were more common after the first dose of Oxford/AstraZeneca vaccine compared to the Pfizer/BioNTech vaccine (69.6% vs 42.6%; p = 0.03). Risk of any grade toxicity (local or systemic) following the first dose was correlated with female sex (p = 0.033). Our study showed that systemic side effects were more common after the first dose of Oxford/AstraZeneca vaccine compared to the Pfizer/BioNTech vaccine in cancer patient, with the predominance of any grade of local or systemic toxicity in women.

Ipsilateral or contralateral boosting of mice with mRNA vaccines confers equivalent immunity and protection against a SARS-CoV-2 Omicron strain.

Boosting with mRNA vaccines encoding variant-matched spike proteins has been implemented to mitigate their reduced efficacy against emerging SARS-CoV-2 variants. Nonetheless, in humans, it remains unclear whether boosting in the ipsilateral or contralateral arm with respect to the priming doses impacts immunity and protection. Here, we boosted K18-hACE2 mice with either monovalent mRNA-1273 (Wuhan-1 spike) or bivalent mRNA-1273.214 (Wuhan-1 + BA.1 spike) vaccine in the ipsilateral or contralateral leg after a two-dose priming series with mRNA-1273. Boosting in the ipsilateral or contralateral leg elicited equivalent levels of serum IgG and neutralizing antibody responses against Wuhan-1 and BA.1. While contralateral boosting with mRNA vaccines resulted in the expansion of spike-specific B and T cells beyond the ipsilateral draining lymph node (DLN) to the contralateral DLN, administration of a third mRNA vaccine dose at either site resulted in similar levels of antigen-specific germinal center B cells, plasmablasts/plasma cells, T follicular helper cells, and CD8+ T cells in the DLNs and the spleen. Furthermore, ipsilateral and contralateral boosting with mRNA-1273 or mRNA-1273.214 vaccines conferred similar homologous or heterologous immune protection against SARS-CoV-2 BA.1 virus challenge with equivalent reductions in viral RNA and infectious virus in the nasal turbinates and lungs. Collectively, our data show limited differences in B and T cell immune responses after ipsilateral and contralateral site boosting by mRNA vaccines that do not substantively impact protection against an Omicron strain.IMPORTANCESequential boosting with mRNA vaccines has been an effective strategy to overcome waning immunity and neutralization escape by emerging SARS-CoV-2 variants. However, it remains unclear how the site of boosting relative to the primary vaccination series shapes optimal immune responses or breadth of protection against variants. In K18-hACE2 transgenic mice, we observed that intramuscular boosting with historical monovalent or variant-matched bivalent vaccines in the ipsilateral or contralateral limb elicited comparable levels of serum spike-specific antibody and antigen-specific B and T cell responses. Moreover, boosting on either side conferred equivalent protection against a SARS-CoV-2 Omicron challenge strain. Our data in mice suggest that the site of intramuscular boosting with an mRNA vaccine does not substantially impact immunity or protection against SARS-CoV-2 infection.

Heterogeneity of SARS-CoV-2 immune responses after the nationwide Omicron wave in China.

It remains unclear how previous infections and vaccinations influenced and shaped heterogeneous immune responses against Omicron and its variants in diverse populations in China. After the national wave of Omicron in early 2023, we evaluated serum levels of neutralizing antibodies (nAbs) against Omicron (B.1.1.529) and its variants (BA.5, BF.7, and CH1.1) in 33 COVID-19 convalescents and 40 uninfected vaccinees, using vesicular stomatitis virus-based pseudovirus neutralizing assay. In addition, we followed 34 Delta convalescent patients to compare their immune responses against Omicron before (late 2021) and after the Omicron wave (early 2023). NAbs at the acute phase of the disease were investigated in 50 Omicron inpatients, including 24 vaccinated and 26 unvaccinated patients. Among them, nasal mucosal IgA levels were measured in 42 subjects. Compared to vaccination, breakthrough infections significantly increased the breadth and magnitude of serum nAbs and mucosal IgA levels against Omicron variants. Exposure to Omicron but not Delta elicited stronger pan-Omicron responses. In Omicron inpatients, nAbs continued to rise as vaccination doses increased. However, in both vaccinees and convalescents, a fourth dose vaccination did not elicit higher nAbs against Omicron. Furthermore, nAbs against Omicron variants lasted longer than nAbs against WT SARS-CoV-2. Breakthrough infections of Omicron variants elicited specific immune responses against Omicron compared to vaccination and Delta infection. Although repeated vaccination revealed limited impacts on serum nAbs, populations at high risk of hospitalization may still benefit from continued vaccination.IMPORTANCEThe study described the specific humoral immunity against Omicron and its variants (BA.5, BF.7, and CH1.1) in diverse populations, including Delta-positive convalescent patients, Omicron-infected patients with a previous or current confirmed Delta infection, Omicron-positive patients, and healthy controls. In addition, we followed Delta convalescents for 1 year to evaluate the effect of a booster vaccine, breakthrough infection, and reinfection. Nasal mucosal IgA levels against SARS-CoV-2 were also examined. The findings of this study demonstrated the varied responses of individuals in different states following the outbreak of Omicron, highlighting the potential advantages of ongoing immunization for groups that are more vulnerable and have a greater likelihood of being hospitalized.

Immunogenicity and Reactogenicity of High-dose or Standard-dose Influenza Vaccine in a Second Consecutive Influenza Season.

Pediatric hematopoietic cell transplant (HCT) recipients are at high-risk for morbidity from influenza virus infection. We demonstrated in a primary phase II randomized controlled trial that two post-HCT doses of high-dose trivalent influenza vaccine (HD-TIV) given four weeks apart were more immunogenic than two doses of standard-dose quadrivalent influenza vaccine (SD-QIV). Herein, we present immunogenicity and safety of influenza vaccination in a consecutive season post-HCT using the same dosing regimen. A subcohort of study participants re-enrolled and had hemagglutinin inhibition (HAI) titers measured at baseline and four weeks after each vaccine dose in year two. We estimated geometric mean fold rise (GMFR) in HAI titer from baseline for each group and used linear mixed effects models to estimate adjusted geometric mean ratios (aGMR, comparing HD-TIV to SD-QIV) for each antigen at each time point. We described systemic and injection-site reactions. A total of 65 subcohort patients participated (33 SD-QIV, 32 HD-TIV). Post-vaccine GMFR and aGMR estimates were higher for both groups following a single influenza vaccine dose in year two compared to two doses of the same formulation in year one. Both groups had similar frequencies of injection-site and systemic reactions. A single dose of HD-TIV or SD-QIV was more immunogenic in year two than two doses of the same formulation in year one. Reactogenicity was comparable between groups. One dose of influenza vaccine may be sufficient after a two-dose schedule in the prior year post-HCT.

COVID-19 Vaccine Safety in Pregnancy, A Nested Case-Control Study in Births From April 2021 to March 2022, England.

Assessment of COVID-19 vaccine safety in pregnancy using population-based data. Matched case-control study nested in a retrospective cohort. April 2021-March 2022, England. All pregnant individuals aged between 18 and 50 years with valid health records. Individuals identified from the national Maternity Services Data Set (MSDS) had their records linked to hospital admission, national COVID-19 vaccine and COVID-19 testing databases. Matching included participant's age and estimated week of conception. We compared outcomes across multiple COVID-19 vaccine exposures using conditional multivariable logistic regression, adjusting for demographic and health characteristics. Adverse pregnancy, maternal and neonatal outcomes. 514 013 individuals were included. We found lower odds of giving birth to a baby who was low birthweight (aOR = 0.86, 95% CI: 0.79-0.93), preterm (aOR = 0.89, 95% CI: 0.85-0.92) or who had an Apgar score < 7 at 5 min of age (aOR = 0.89, 95% CI: 0.80-0.98) for individuals who received at least one dose of COVID-19 vaccine during pregnancy. The odds of admission to intensive care unit during pregnancy were lower in those vaccinated (aOR = 0.85, 95% CI: 0.76-0.95). There was no association between vaccination in pregnancy and stillbirth, neonatal death, perinatal death and maternal venous thromboembolism in pregnancy. COVID-19 vaccines are safe to use in pregnancy. Our findings generated important information to communicate to pregnant individuals and health professionals to support COVID-19 maternal vaccination programmes.

The Effects of Vaccination Status and Age on Clinical Characteristics and Severity of Measles Cases in the United States in the Post-Elimination Era, 2001-2022.

Despite high vaccine-effectiveness, wild-type measles can occur in previously vaccinated persons. We compared the clinical presentation and disease severity of measles by vaccination status and age in the post-elimination era in the United States. We included U.S. measles cases reported from 2001-2022. Breakthrough measles was defined as cases with ≥1 documented dose of measles-containing vaccine, classic measles as the presence of rash, fever, and ≥1 symptoms (cough, coryza, or conjunctivitis), and severe disease as the presence of pneumonia, encephalitis, hospitalization, or death. Vaccinated cases with low and high avidity IgG were classified as primary (PVF) and secondary (SVF) vaccine failures, respectively. Among 4,056 confirmed measles cases, 2,799 (69%) were unvaccinated, 475 (12%) were breakthrough infections, and 782 (19%) had unknown vaccination; 1,526 (38%), 1,174 (29%), and 1,355 (33%) were aged <5, 5-19, and ≥20 years, respectively. We observed a general decline in classic presentation and severe disease with an increase in the number of doses, and less complications among children aged 5-19 years compared to other age-groups. Among 93 breakthrough cases with avidity results, 11 (12%) and 76 (82%) were classified as PVF and SVF, respectively, with a higher proportion of PVFs having a classic measles presentation and severe disease than SVFs. Breakthrough measles cases tended to have milder disease with less complications. A small proportion of breakthrough infections were due to PVF than SVF. It is critical to maintain high MMR vaccination coverage in the United States to prevent serious measles illnesses.

Comparison of viraemia and nasal shedding after PRRSV-1 challenge following vaccination with three commercially available PRRS modified live virus vaccines

The effectiveness of three Porcine Reproductive and Respiratory Syndrome (PRRS) Modified Live Virus (MLV) vaccines against PRRSV viraemia and nasal shedding following experimental challenge was compared. The study comprised a negative control (T01), and three treatment groups (T02, T03 and T04) each vaccinated with a single dose of a commercial PRRS MLV vaccine, given in accordance with the vaccine's Summary of Product Characteristics (SPC). Pigs aged 21 days were vaccinated (day 0), challenged intranasally (day 28) with heterologous PRRSV-1-1 strain Olot/91, then monitored for PRRSV viraemia and nasal shedding for 12 days. After challenge, pigs were viraemic on fewer days in group T04 (0.67) than groups T01 (0.91), T02 (0.81) and T03 (0.97) (P < 0.0296). From day 34, inclusive, serum PRRSV titres were lower in group T04 than negative controls (P ≤ 0.0001) and groups T02 and T03 (P ≤ 0.0047); serum PRRSV titre Area Under the Curve (AUC) for group T04 (42.34) was lower than in T01 (65.49), T02 (60.67) and T03 (67.38) (P < 0.0100); pigs exhibited nasal shedding on fewer days in group T04 (0.40) than T01 (0.78), T02 (0.64) and T03 (0.56) (P < 0.0101); and nasal shedding AUC for group T04 (8.52) was lower than in groups T01 (23.59, P < 0.0001) and T02 (19.37, P = 0.0001). The ability of PRRS MLV vaccines to reduce the duration of viraemia and nasal shedding after intranasal challenge with a heterologous PRRSV-1-1 strain differ significantly.

Immunogenicity and safety of different dose levels of Ad26.RSV.preF/RSV preF protein vaccine in adults aged 60 years and older: A randomized, double-blind, placebo-controlled, phase 2a study

BackgroundRespiratory syncytial virus (RSV) can cause severe illness in older adults. A combination vaccine containing Ad26.RSV.preF and purified recombinant RSV preF protein has previously demonstrated efficacy and tolerability in older adults. We report results of a dose-ranging study to determine immunogenicity and safety of different doses of the Ad26.RSV.preF component in the combined Ad26.RSV.preF/RSV preF protein vaccine to support Ad26.RSV.preF drug product release and stability specifications. MethodsIn this randomized, double-blind, placebo-controlled, phase 2a study, adults aged ≥60 years in good or stable health were randomly assigned within 1 of 3 cohorts to receive either placebo or Ad26.RSV.preF/RSV preF protein, composed of different doses of Ad26.RSV.preF with a fixed dose of RSV preF protein (150 μg). Ad26.RSV.preF doses in Cohort 1 (4 dose-down groups) ranged from 3.7 × 109 to 1.0 × 1011 viral particles (vp). Doses in Cohorts 2 and 3 (2 dose-up groups, each) ranged from 1.0 to 1.6 × 1011 vp. Primary endpoints were immunogenicity (RSV preF protein antibody titers) for Cohort 1 and safety (solicited local and systemic adverse events [AEs] and unsolicited AEs) for Cohorts 2 and 3. Immunogenicity analyses (RSV preF protein antibody titers, RSV A2 neutralizing antibodies, and RSV-F–specific interferon-γ enzyme-linked immunosorbent spot) were performed on the day of vaccination and 14 days, 3 months, and 6 months postvaccination. Safety was monitored from vaccination until study end. ResultsOverall, 454 participants were enrolled and received 1 dose of study vaccine or placebo (Cohort 1, n = 226; Cohort 2, n = 124; Cohort 3, n = 104). No substantial differences in measured immune responses were observed between lower or higher Ad26.RSV.preF doses compared with Ad26.RSV.preF 1.0 × 1011 vp across all postvaccination time points. All Ad26.RSV.preF doses between 3.7 × 109 vp and 1.6 × 1011 vp were well tolerated, with no safety issues identified. ConclusionsResults of this dose-ranging study may be used to inform the refinement of Ad26.RSV.preF drug product release and stability specifications.Clinical Trial Registration:ClinicalTrials.gov Identifier: NCT04453202

Kinetics of humoral and cellular immune responses 5 months post-COVID-19 booster dose by immune response groups at the peak immunity phase: An observational historical cohort study using the Fukushima vaccination community survey

BackgroundUnderstanding the waning of immunity after booster vaccinations is important to identify which immune-low populations should be prioritized. MethodsWe investigated longitudinal cellular and humoral immunity after the third vaccine dose in both high- and low-cellular and humoral immunity groups at the peak immunity phase after the booster vaccination in a large community-based cohort. Blood samples were collected from 1045 participants at peak (T1: median 54 days post-third dose) and decay (T2: median 145 days post-third dose) phases to assess IgG(S), neutralizing activity, and ELISpot responses. Participants were categorized into high/low ELISpot/IgG(S) groups at T1. Cellular and humoral responses were tracked for approximately five months after the third vaccination. ResultsIn total, 983 participants were included in the cohort. IgG(S) geometric mean fold change between timepoints revealed greater waning in the >79 years age group (T2/T1 fold change: 0.27) and higher IgG(S) fold change in the low-ELISpot group at T1 (T2/T1 fold change: 0.32–0.33) than in the other groups, although ELISpot geometric mean remained stable. ConclusionsAntibody level of those who did not respond well to third dose vaccination waned rapidly than those who responded well. Evidence-based vaccine strategies are essential in preventing potential health issues caused by vaccines, including side-effects.

Prevalence and factors influencing long COVID among primary healthcare workers after epidemic control policy adjustment in Jiangsu, China

ObjectiveThe persistent symptoms arising from COVID-19 infection pose a substantial threat to patients’ health, carrying significant implications. Amidst the evolving COVID-19 control strategies in China, healthcare workers (HCWs) endure considerable stress. This study aims to evaluate the prevalence of long COVID infections and their influencing factors among primary HCWs after epidemic control policy adjustment in Jiangsu.MethodsA self-designed questionnaire was administered through on-site surveys among primary HCWs in five counties and districts within Jiangsu Province from July 4 to July 20, 2023. Logistic regression analysis was employed to identify factors associated with long COVID.ResultsThe prevalence of long COVID among primary HCWs stood at 12.61%, with a 95% confidence interval (CI) of 11.67-13.55%. Among those affected, the most common long COVID symptoms were hypomnesia (4.90%, 95%CI: 4.29-5.51%), sleep difficulties (2.73%, 95%CI: 2.27-3.19%), fatigue (2.35%, 95%CI: 1.92-2.78%), disturbances in the reproductive system (1.93%, 95%CI: 1.54-2.32%), hair loss (1.85%, 95%CI: 1.47-2.23%), and myalgia/arthralgia (1.51%, 95%CI: 1.16-1.86%). Multivariate logistic regression revealed that older age groups (30–45 years (adjusted odds ratio (aOR) = 1.93, 95%CI: 1.44–2.58), 45–60 years (aOR = 2.82, 95%CI: 2.07–3.84)), females (aOR = 1.26, 95%CI: 1.03–1.55), and higher work stress (high stress (aOR = 1.52, 95%CI: 1.24–1.86), extremely high stress (aOR = 1.37, 95%CI: 1.03–1.82)) were more prone to long COVID. Conversely, individuals with educational attainment below the bachelor’s degree (aOR = 0.67, 95%CI: 0.55–0.82) and those who received four or more doses of the COVID-19 vaccine (aOR = 0.55, 95%CI: 0.33–0.92) were at a reduced risk.ConclusionThis study investigates the prevalence of long COVID among primary HCWs and identifies key influencing factors. These findings are crucial for assisting in the early identification of COVID-19 patients at risk for long-term complications, developing targeted interventions aimed at optimizing healthcare resource allocation and enhancing the work conditions and quality of life of HCWs. To mitigate the prevalence of long COVID, healthcare providers and local authorities should implement effective measures, such as optimizing work-rest schedules and actively advocating for vaccination.

Use of Haemophilus influenzae Type b-Containing Vaccines Among American Indian and Alaska Native Infants: Updated Recommendations of the Advisory Committee on Immunization Practices - United States, 2024.

Invasive Haemophilus influenzae type b (Hib) disease is a serious bacterial infection that disproportionally affects American Indian and Alaska Native (AI/AN) populations. Hib vaccination with a monovalent Hib conjugate vaccine consisting of Hib capsular polysaccharide (polyribosylribitol phosphate [PRP]) conjugated to outer membrane protein complex of Neisseria meningitidis serogroup B, PRP-OMP (PedvaxHIB, Merck and Co., Inc.) has historically been preferred for AI/AN infants, who are at increased risk for invasive Hib disease, because it provides substantial protection after the first dose. On June 26, 2024, CDC's Advisory Committee on Immunization Practices (ACIP) recommended that a hexavalent, combined diphtheria and tetanus toxoids and acellular pertussis (DTaP), inactivated poliovirus (IPV), Hib conjugate, and hepatitis B (HepB) vaccine, DTaP-IPV-Hib-HepB (Vaxelis, MSP Vaccine Company) should be included with monovalent PRP-OMP in the preferential recommendation for AI/AN infants because of the PRP-OMP Hib component. A primary Hib vaccination series consisting of either 1) monovalent PRP-OMP (2-dose series at ages 2 and 4 months) or 2) DTaP-IPV-Hib-HepB (3-dose series at ages 2, 4, and 6 months) is preferred for AI/AN infants. DTaP-IPV-Hib-HepB is only indicated for use in infants at ages 2, 4, and 6 months and should not be used for the booster doses of Hib, DTaP, or IPV vaccines. For the booster dose of Hib vaccine, no vaccine formulation is preferred for AI/AN children; any Hib vaccine (except DTaP-IPV-Hib-HepB) should be used. This report summarizes evidence considered for these recommendations and provides clinical guidance for the use of Hib-containing vaccines among AI/AN infants and children.

Hepatitis a vaccine immunogenicity and boostability in adults receiving immunosuppressive therapy and adults living with HIV: a prospective single-Centre cohort study.

Hepatitis A (hepA) vaccination is highly immunogenic in healthy individuals, however there is uncertainty about the immunogenicity in immunocompromised populations (ICPs). In this prospective cohort study, people living with HIV (PLWH), patients on immunosuppressive mono- and combination therapy, and controls received two hepA vaccine doses at months 0 and 6-12, or three combined hepA/B vaccine doses at months 0, 1 and 6-12. Antibody levels were measured before and at different time-points post-vaccination (T2, 6, 8, 12months). The primary endpoint was the seroconversion rate (SCR) at T8, defined as hepA antibodies ≥20 mIU/ml. To assess boostability, an additional vaccine dose was administered 1-5years after T12 in those with antibodies < 50 mIU/ml, with antibody measurements before and seven days after the booster dose. We included 150 participants. At T2 SCRs ranged between 35-58% in ICPs versus 94% in controls. Among PLWH, patients on monotherapy, combination therapy and controls SCRs at T8 were 33/34 (97%), 32/34 (94%), 25/30 (83%) and 28/28 (100%) respectively. The booster dose resulted in 71% additional seroconversion (17/24), with only patients using combination therapy not responding. HepA vaccination is highly immunogenic in virologically suppressed PLWH and patients on immunosuppressive monotherapy, with SCRs after the complete hepA vaccination schedule similar to controls and adequate booster responses in case of waning immunity. However, patients using immunosuppressive combination therapy as well as all ICPs who did not receive the complete hepA vaccination schedule, are at risk of non-response to vaccination and post-vaccination antibody measurements are recommended.

A Preliminary Study to Evaluate the Immune Response to a Booster Dose of the Adult Tetanus-Diphtheria Vaccine (Td) Available in Iran

Background: Despite the availability of tetanus-diphtheria (TD) vaccines in Iran, the seroconversion rate of these products as a booster dose is unknown. Objectives: This study evaluates the seroconversion rate of the Iranian Td vaccine in adults who have not been vaccinated in the past decade. Methods: In this study, 20 adult volunteers aged 18 to 60 who had not received the Td vaccine in the past decade received a booster dose of the Iranian Td vaccine. Twenty-eight days after vaccination, the seroconversion rate was evaluated using the ELISA method. Vaccine adverse events were monitored at three time points after vaccination. Results: Seroconversion rates with the Iranian Td vaccine boosters were 75% and 90%, respectively, based on a 4-fold increase in anti-tetanus toxoid antibody titers and a 2- and 4-fold combination. Significant associations were found between the demographic data, specifically female gender and age 43 years and older, with seroconversion rates. Injection-site pain was the most common adverse reaction, with a frequency of 35%. No adverse events were reported between one week and one month after vaccination. Conclusions: Results showed that a booster dose of the Iranian Td vaccine produced a protective titer (&gt; 0.1 IU/mL) and a long-term protective titer (&gt; 1.0 IU/mL) in 100% of participants. The seroconversion rate of the Iranian Td vaccine was comparable to other common tetanus vaccines, including Tenivac®, Adacel®, Infanrix®, Tetavax®, and Vacteta®. The proportion of suitable candidates for plasma donation, based on minimum (2 IU/mL) and maximum (10 IU/mL) anti-tetanus toxoid antibody titers, was 100% and 45%, respectively.

COVID-19 vaccine uptake in a predominantly minoritized cohort hospitalized during the early pandemic in New York City

BackgroundMinoritized communities in the United States have had higher COVID-19 mortality and lower vaccine uptake. The influence of previous SARS-CoV-2 infection, initial disease severity, and persistent symptoms on COVID-19 vaccine uptake in Black and Latinx communities has not been examined. ObjectiveTo investigate whether initial COVID-19 severity, persistent symptoms, and other correlates affected vaccine uptake in a predominantly minoritized cohort hospitalized for COVID-19 during the early pandemic in New York City. DesignIn this historical cohort study, we abstracted electronic health record data on demographics, comorbidities, hospital oxygen requirements, symptoms at 3 and 6 months post-admission, COVID-19 vaccinations through November 2022, and influenza vaccinations during the 2018–2019 through 2021–2022 seasons. Unadjusted and adjusted odds ratios were estimated through logistic regression analyses of correlates of COVID-19 vaccination, on-time vaccination, and boosting. ParticipantsSurvivors among the first 1186 adult patients hospitalized for COVID-19 between March 1 and April 8, 2020 at a large quaternary care medical center in Northern Manhattan. Main MeasuresUptake of at least one COVID-19 vaccine dose, uptake of at least one booster, and on-time vaccination. Key ResultsThe 890 surviving individuals were predominantly Latinx (54%) and Non-Hispanic Black (15%). Most had one or more comorbidities (67%), and received at least one COVID-19 vaccine dose (78%). Among those vaccinated, 57% received at least one booster, and 31% delayed vaccination. 67% experienced persistent symptoms. Multiple logistic regression showed no association between vaccine uptake and disease severity or symptom persistence. However, older age and influenza vaccination during the COVID-19 era were associated with increased vaccination, booster uptake, and on-time vaccination. ConclusionsPinpointing drivers of vaccine uptake and hesitancy is critical to increasing and sustaining COVID-19 vaccination as the field transitions to annual boosters. The association between influenza vaccination and increased vaccine uptake suggests that bundling vaccines for adults may be an effective delivery strategy.