Intratumor injection of BCG Ag85A high-affinity peptides enhanced anti-tumor efficacy in PPD-positive melanoma.

As one of the scheduled immunization vaccines worldwide, virtually all individuals have been vaccinated with BCG vaccine. In order to verify the hypothesis that delivering BCG high-affinity peptides to tumor areas could activate the existing BCG memory T cells to attack tumor, we firstly predicted the HLA-A*0201 high-affinity peptides of BCG Ag85A protein (KLIANNTRV, GLPVEYLQV), and then, A375 melanoma cells and HLA-A*0201 PBMCs (from PPD-positive adults) were added to co-incubated with the predicted peptides in vitro. We found that the predicted BCG high-affinity peptides could be directly loaded onto the surface of tumor cells, enhancing the tumor-killing efficacy of PBMCs from PPD-positive volunteer. Then, we constructed PPD-positive mice model bearing B16F10 subcutaneous tumors and found that intratumor injection of BCG Ag85A high-affinity peptides (SGGANSPAL, YHPQQFVYAGAMSGLLD) enhanced the anti-tumor efficacy in PPD-positive melanoma mice. Along with the better anti-tumor efficacy, the expression of PDL1 on tumor cell surface was also increased, and stronger antitumor effects occurred when further combined with anti-PD1 antibody. For microenvironment analysis, the proportion of effector memory T cells was increased and the better treatment efficacy may be attributed to the elevated effector memory CD4 + T cells within the tumor. In conclusion, using the existing immune response of BCG vaccine by delivering high-affinity peptides of BCG to tumor area is a safe and promising therapy for cancer.

CoPoP liposomes displaying stabilized clade C HIV-1 Env elicit tier 2 multiclade neutralization in rabbits.

One of the strategies towards an effective HIV-1 vaccine is to elicit broadly neutralizing antibody responses that target the high HIV-1 Env diversity. Here, we present an HIV-1 vaccine candidate that consists of cobalt porphyrin-phospholipid (CoPoP) liposomes decorated with repaired and stabilized clade C HIV-1 Env trimers in a prefusion conformation. These particles exhibit high HIV-1 Env trimer decoration, serum stability and bind broadly neutralizing antibodies. Three sequential immunizations of female rabbits with CoPoP liposomes displaying a different clade C HIV-1 gp140 trimer at each dosing generate high HIV-1 Env-specific antibody responses. Additionally, serum neutralization is detectable against 18 of 20 multiclade tier 2 HIV-1 strains. Furthermore, the peak antibody titers induced by CoPoP liposomes can be recalled by subsequent heterologous immunization with Ad26-encoded membrane-bound stabilized Env antigens. Hence, a CoPoP liposome-based HIV-1 vaccine that can generate cross-clade neutralizing antibody immunity could potentially be a component of an efficacious HIV-1 vaccine.

Vaccination Timeliness Among US Children Aged 0-19 Months, National Immunization Survey-Child 2011-2021.

Importance: Delays in receiving vaccinations lead to greater vaccine-preventable disease risk. Timeliness of receipt of recommended vaccinations is not routinely tracked in the US, either overall or for populations that have known barriers to accessing routine health care, including lower-income families and children. Objective: To measure vaccination timeliness among US children aged 0 to 19 months, overall and by socioeconomic indicators. Design, Setting, and Participants: This serial, cross-sectional study analyzed nationally representative data from the 2011 to 2021 National Immunization Survey-Child (NIS-Child), an annual survey of parents, with immunization histories collected from clinicians administering vaccines. The 2020 and 2021 surveys largely reflected vaccinations in the US before the COVID-19 pandemic. Study participants included US children surveyed at ages 19 to 35 months. Data were analyzed from January to August 2023. Exposure: Survey year. Main Outcomes and Measures: The primary outcomes were average days undervaccinated (ADU) and percentage of children who received all vaccine doses on time (ie, 0 days undervaccinated) for the combined 7-vaccine series up to age 19 months. The mean adjusted annual change in on-time vaccination by socioeconomic indicators was calculated by use of multivariable log-linked binomial regression models. Results: The surveys included 179 154 children (92 248 boys [51.2%]); 74 479 (31.4%, weighted) lived above the federal poverty level with more than $75 000 in annual family income, 58 961 (32.4%) lived at or above the poverty level with $75 000 or less in annual family income, and 39 564 (30.2%) lived below the poverty level. Overall, the median (IQR) ADU for the combined 7-vaccine series in the US decreased from 22.3 (0.4-71.5) days in the 2011 survey to 11.9 (0.0-55.5) days in the 2021 survey. The prevalence of on-time receipt of the combined 7-vaccine series increased from 22.5% (95% CI, 21.4%-23.6%) to 35.6% (95% CI, 34.2%-37.0%). Although children with more than $75 000 in annual family income had a 4.6% (95% CI, 4.0%-5.2%) mean annual increase in on-time vaccination, the mean annual increase was 2.8% (95% CI, 2.0%-3.6%) for children living at or above the poverty level with $75 000 or less in annual family income and 2.0% (95% CI, 1.0%-3.0%) for children living below the poverty level. Conclusions and Relevance: In this cross-sectional study of NIS-Child data, improvements in vaccination timeliness were observed from the 2011 to the 2021 survey. However, widening disparities by socioeconomic indicators signal that increased efforts to facilitate timely vaccination among children in lower-income families are needed.

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.

Impact of COVID -19 on expanded programme on Immunisation in District Dir lower Khyber Pakhtunkhwa.

Objectives: To study the impact of coronavirus disease-2019 on Expanded Programme on Immunisation in a rural setting. METHODS: The descriptive, cross-sectional study was conducted in five union councils of District Dir Lower, in the Khyber Pakhtunkhwa province of Pakistan. Data was collected from March to August 2020, which was a period of lockdowns in the wake of the coronavirus disease-2019, and then from March to August 2021. The sample comprised children aged <2 years. Data was analysed using SPSS 25. RESULTS: Of the 330 children, 210(63.6%) were boys, and 120(36.4%) were girls, and all 330(100%) were located in rural areas. First-phase data showed that the maximum coverage rate of immunisation was 258(78.2%) noted in OPV1(Oral Polio Vaccine) Penta1(Pentavalent vaccine), PCV10-1 (Pneumococcal pneumonia) and Rota 1(Rota Vaccine), and the least vaccination rate was 68.2% for Measle-1. In the second phase, 23% incline was noted in Measles-2 vaccination, followed by 16.3% in OPV2, Penta 2, PCV10-2 and Rota 2, 16% in Measles-1, 14% in OPV-3, Penta-3, PCV10-3, Rota-3 and IPV, 11.5% in OPV-1, Penta-1, PCV10-1, and Rota-1, and 10.6% in OPV-0 and BCG-0. CONCLUSIONS: Immunisation programme was affected by lockdowns during the active phase of the coronavirus disease-2019 pandemic.

Factors associated with immunization status among children aged 12-59 months in Lagelu local government area, Ibadan: a cross-sectional study.

Introduction: childhood deaths from preventable causes remain high in Nigeria. Although vaccines are available to combat many of these diseases, vaccine coverage remains low in many at-risk communities. With this study, we aimed to determine factors that might have impacted the use of immunization services in Ibadan, the capital of Oyo State in southwest Nigeria. Methods: we conducted a community-based cross-sectional study in a peri-urban local government area in Ibadan using a multi-stage cluster sampling technique to identify respondents for this study. The interviewer-administered questionnaire was used to obtain information on respondents and child socio-demographic details. We reviewed the child´s vaccine card to determine vaccine status. Data were analyzed using STATA version 14 at a 5% level of significance. Results: of the 265 children aged 12 to 59 months who had their vaccine cards appropriately filled, only 65.3% (n=173) received all basic vaccines, while 90.2% (n=239) and 86.8% (n=230) received 3 doses of pentavalent vaccine (PENTA) and pneumococcal conjugate vaccines (PCV-10) respectively. We found a significant difference in the completion of basic vaccination according to the caregiver´s place of residence and the mother´s educational level. Access-related barriers were frequently reported (n=24, 54.5%) as reasons for missing a due vaccine. Conclusion: improvement in vaccine coverage in this setting is necessary. Targeted health information for mothers may be a cost-efficient and sustainable approach to improve vaccine coverage for under-five children.

[Strategies and recommendations to face respiratory syncytial virus disease in 2024]. / Estrategias y recomendaciones para enfrentar la enfermedad por virus respiratorio sincicial el año 2024.

During the winter of 2023, Chile faced a complex situation related to the respiratory syncytial virus (RSV). After experiencing a decline in RSV circulation during the years of the SARS-CoV-2 pandemic, a late outbreak was observed in the spring of 2022 and an early onset of the outbreak in 2023, with a significant increase in the number of serious cases. The ineffectiveness of strategic planning and risk communication contributed to the complexity of the situation. To avoid the above next winter, measures such as active surveillance, unification of definitions for acute respiratory infections, identification of RSV variants, public education about infections and advance preparation regarding hospital beds and health personnel are suggested. The importance of immunization and intersectoral collaboration to acquire new preventive alternatives is highlighted, as well as the need for early communication about the importance of immunization and identification of high-risk groups, improvement in training of medical personnel and strategic planning of the Ministry of Health. seeking a proactive and collaborative approach to address the complex RSV situation in future winters. The Chilean Immunization Advisory Committee has already carried out an analysis and recommendation on a new prevention alternative. This working group will support any decision of the Ministry of Health in public policies that attempt a change in the paradigm of control of this disease for the health of the children of our country.

Setting up a data system for monitoring malaria vaccine introduction readiness and uptake in 42 health districts in Cameroon.

Three months after the first shipment of RTS,S1/AS01 vaccines, Cameroon started, on 22 January 2024, to roll out malaria vaccines in 42 districts among the most at risk for malaria. Cameroon adopted and implemented the World Health Organization (WHO) malaria vaccine readiness assessment tool to monitor the implementation of preintroduction activities at the district and national levels. One week before the start of the vaccine rollout, overall readiness was estimated at 89% at a national level with two out of the five components of readiness assessment surpassing 95% of performance (vaccine, cold chain and logistics and training) and three components between 80% and 95% (planning, monitoring and supervision, and advocacy, social mobilisation and communication). 'Vaccine, cold chain and logistics' was the component with the highest number of districts recording below 80% readiness. The South-West and North-West, two regions with a high level of insecurity, were the regions with the highest number of districts that recorded a readiness performance below 80% in the five components. To monitor progress in vaccine rollout daily, Cameroon piloted a system for capturing immunisation data by vaccination session coupled with an interactive dashboard using the R Shiny platform. In addition to displaying data on vaccine uptake, this dashboard allows the generation of the monthly immunisation report for all antigens, ensuring linkage to the regular immunisation data system based on the end-of-month reporting through District Health Information Software 2. Such a hybrid system complies with the malaria vaccine rollout principle of full integration into routine immunisation coupled with strengthened management of operations.

Immunostimulation of Asian elephant (Elephas maximus) blood cells by parapoxvirus ovis and CpG motif-containing bacterial plasmid DNA upregulates innate immune gene expression.

The immune system of Asian elephants (Elephas maximus) is poorly studied, compared to that of livestock, rodents or humans. The innate immune response has become a focus of interest in relation to Elephant endotheliotropic herpesviruses (EEHVs). EEHVs cause a fatal hemorrhagic disease (EEHV-HD) and are a significant threat to captive Asian elephant populations worldwide. Similar to other herpesvirus infections, nearly all animals become infected, but only some develop disease. As progression to EEHV-HD is often acute, a robust innate immune response is crucial to control EEHV infections. This is invariably true of the host in the first instance, but it can also potentially be modulated by intervention strategies. Here, two immunostimulant veterinary medicinal products, authorized for use in domestic species, were tested for their ability to induce innate anti-viral immune responses in Asian elephant blood cells. Sequence data were obtained for a range of previously unidentified Asian elephant immune genes, including C-X-C motif chemokine ligand 10 (CXCL10), interferon stimulated gene 15 (ISG15) and myxovirus GTPase 1 (Mx1), and were employed in the design of species-specific qPCR assays. These assays were subsequently used in analyses to determine fold changes in gene expression over a period of 24 hours. This study demonstrates that both immunostimulant medications are capable of inducing significant innate anti-viral immune responses which suggests that both could be beneficial in controlling EEHV infections in Asian elephants.

Twenty Years of Progress and the Way Forward: Immunization Registry Information System in Korea.

The National Immunization Program in The Republic of Korea offers mandatory and free vaccinations to children under 12, regulated by the Infectious Disease Prevention and Control Act. Tracking vaccination coverage is crucial for population protection and public health strategies. Since 2002, the Immunization Registry Information System (IRIS) has been used nationwide to capture vaccination data. This study reviewed documents related to IRIS's establishment and development. The Republic of Korea legally supports IRIS's construction and data collection, integrating vaccination data with the Ministry of the Interior and Safety's resident registration to minimize errors. This collaboration also facilitates cost reimbursement and digital registration, promoting wider vaccination coverage. IRIS manages expense claims once vaccination details are logged, and authorized medical institutions can access these records in real-time. Since 2015, the Korea Disease Control and Prevention Agency has been compiling annual data on national vaccination coverage. IRIS also sends automated reminders in 12 languages, reports adverse effects, and issues vaccination certificates. However, IRIS lacks integration between vaccine and disease registries, unlike countries such as England, Denmark, and the Netherlands. Improving integration capabilities could enhance IRIS's support for public health through an integrated information system.

Immunization with a peptide mimicking lipoteichoic acid induces memory B cells in BALB/c mice.

BACKGROUND: There is an urgent clinical need for developing novel immunoprophylaxis and immunotherapy strategies against Staphylococcus aureus (S. aureus). In our previous work, immunization with a tetra-branched multiple antigenic peptide, named MAP2-3 that mimics lipoteichoic acid, a cell wall component of S. aureus, successfully induced a humoral immune response and protected BALB/c mice against S. aureus systemic infection. In this study, we further investigated whether vaccination with MAP2-3 can elicit immunologic memory. METHODS: BALB/c mice were immunized with MAP2-3 five times. After one month of the last vaccination, mice were challenged with heat-killed S. aureus via intraperitoneal injection. After a 7-day inoculation, the percentage of plasma cells, memory B cells, effector memory T cells, and follicular helper T cells were detected by flow cytometry. The levels of IL-6, IL-21, IL-2, and IFN-γ were measured by real-time PCR and ELISA. Flow cytometry results were compared by using one-way ANOVA or Mann-Whitney test, real-time PCR results were compared by using one-way ANOVA, and ELISA results were compared by using one-way ANOVA or student's t-test. RESULTS: The percentage of plasma cells and memory B cells in the spleen and bone marrow from the MAP2-3 immunized mice was significantly higher than that from the control mice. The percentage of effector memory T cells in spleens and lymphoid nodes as well as follicular helper T cells in spleens from the MAP2-3 immunized mice were also higher. Moreover, the levels of IL-6 and IL-21, two critical cytokines for the development of memory B cells, were significantly higher in the isolated splenocytes from immunized mice after lipoteichoic acid stimulation. CONCLUSIONS: Immunization with MAP2-3 can efficiently induce memory B cells and memory T cells.

Vaccine-elicited IL-1R signaling results in Th17 TRM-mediated immunity.

Lung tissue resident memory (TRM) cells are thought to play crucial roles in lung host defense. We have recently shown that immunization with the adjuvant LTA1 (derived from the A1 domain of E. coli heat labile toxin) admixed with OmpX from K. pneumoniae can elicit antigen specific lung Th17 TRM cells that provide serotype independent immunity to members of the Enterobacteriaceae family. However, the upstream requirements to generate these cells are unclear. Single-cell RNA-seq showed that vaccine-elicited Th17 TRM cells expressed high levels of IL-1R1, suggesting that IL-1 family members may be critical to generate these cells. Using a combination of genetic and antibody neutralization approaches, we show that Th17 TRM cells can be generated independent of caspase-1 but are compromised when IL-1α is neutralized. Moreover IL-1α could serve as a molecular adjuvant to generate lung Th17 TRM cells independent of LTA1. Taken together, these data suggest that IL-1α plays a major role in vaccine-mediated lung Th17 TRM generation.

Incidence and outcome of COVID-19 following vaccine and hybrid immunity in patients on immunosuppressive therapy: identification of protective post-immunisation anti-RBD antibody levels in a prospective cohort study.

OBJECTIVES: To assess incidence, severity and predictors of COVID-19, including protective post-vaccination levels of antibodies to the receptor-binding domain of SARS-CoV-2 spike protein (anti-RBD), informing further vaccine strategies for patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressive medication. METHODS: IMIDs on immunosuppressives and healthy controls (HC) receiving SARS-CoV-2 vaccines were included in this prospective observational study. COVID-19 and outcome were registered and anti-RBD antibodies measured 2-5 weeks post-immunisation. RESULTS: Between 15 February 2021 and 15 February 2023, 1729 IMIDs and 350 HC provided blood samples and self-reported COVID-19. The incidence of COVID-19 was 66% in patients and 67% in HC, with re-infection occurring in 12% of patients. Severe COVID-19 was recorded in 22 (2%) patients and no HC. No COVID-19-related deaths occurred. Vaccine-induced immunity gave higher risk of COVID-19 (HR 5.89 (95% CI 4.45 to 7.80)) than hybrid immunity. Post-immunisation anti-RBD levels <6000 binding antibody units/mL were associated with an increased risk of COVID-19 following three (HR 1.37 (95% CI 1.08 to 1.74)) and four doses (HR 1.28 (95% CI 1.02 to 1.62)), and of COVID-19 re-infection (HR 4.47 (95% CI 1.87 to 10.67)). CONCLUSION: Vaccinated patients with IMID have a low risk of severe COVID-19. Hybrid immunity lowers the risk of infection. High post-immunisation anti-RBD levels protect against COVID-19. These results suggest that knowledge on COVID-19 history, and assessment of antibody levels post-immunisation can help individualise vaccination programme series in high-risk individuals. TRIAL REGISTRATION NUMBER: NCT04798625.

Use of the Pfizer Pentavalent Meningococcal Vaccine Among Persons Aged ≥10 Years: Recommendations of the Advisory Committee on Immunization Practices - United States, 2023.

Meningococcal disease is a life-threatening invasive infection caused by Neisseria meningitidis. Two quadrivalent (serogroups A, C, W, and Y) meningococcal conjugate vaccines (MenACWY) (MenACWY-CRM [Menveo, GSK] and MenACWY-TT [MenQuadfi, Sanofi Pasteur]) and two serogroup B meningococcal vaccines (MenB) (MenB-4C [Bexsero, GSK] and MenB-FHbp [Trumenba, Pfizer Inc.]), are licensed and available in the United States and have been recommended by CDC's Advisory Committee on Immunization Practices (ACIP). On October 20, 2023, the Food and Drug Administration approved the use of a pentavalent meningococcal vaccine (MenACWY-TT/MenB-FHbp [Penbraya, Pfizer Inc.]) for prevention of invasive disease caused by N. meningitidis serogroups A, B, C, W, and Y among persons aged 10-25 years. On October 25, 2023, ACIP recommended that MenACWY-TT/MenB-FHbp may be used when both MenACWY and MenB are indicated at the same visit for the following groups: 1) healthy persons aged 16-23 years (routine schedule) when shared clinical decision-making favors administration of MenB vaccine, and 2) persons aged ≥10 years who are at increased risk for meningococcal disease (e.g., because of persistent complement deficiencies, complement inhibitor use, or functional or anatomic asplenia). Different manufacturers' serogroup B-containing vaccines are not interchangeable; therefore, when MenACWY-TT/MenB-FHbp is used, subsequent doses of MenB should be from the same manufacturer (Pfizer Inc.). This report summarizes evidence considered for these recommendations and provides clinical guidance for the use of MenACWY-TT/MenB-FHbp.

Study on awareness and management based health action using video intervention (SAMBHAV) for postpartum depression among mothers attending immunisation clinic in a tertiary medical college hospital: Study protocol.

INTRODUCTION: Pregnancy exerts a detrimental effect on women's mental health. Maternal mental health is considered as one of the public health concerns as it impacts the health of both mother and the child. One in five people in developing countries experience serious mental health issues during pregnancy and after giving birth. In India, postpartum depression (PPD) affects 22% of women, according to a research by WHO. The available data on mental health literacy among women, showed that only 50.7% of the postpartum mothers who were attending paediatric tertiary care centres had adequate knowledge about PPD. It is crucial to diagnose early and adequately manage postpartum depression to avoid long-term consequences. It is also essential to seek help and utilise the available resources and services to avoid worsening of the condition and to aid in the recovery. This demonstrates the need to promote awareness, improve help seeking, reduce stigma and treatment gap associated with PPD through educational video intervention specific to cultural context and beliefs. MATERIALS AND METHODS: This is a quasi-experimental study without a control group that attempts to improve the awareness among the mothers about postpartum depression to understand better about the condition and also its management through video intervention. The video intervention will be developed in regional language specific to the cultural context of the setting. The video script will be finalised from the findings of the available literature and also through focus group discussion among mothers and health care professionals which will be analysed qualitatively using thematic identification. The study will use a standardized Postpartum Depression Literacy Scale (PoDLIS) which will be quantitatively analysed using paired t test before and after the intervention. Repeated measures of ANOVA will also be used to analyse the changes in literacy scale scores with respect to socio demographic variables. The mothers will also be screened for PPD using Patient Health Questionnaire 9 (PHQ 9) and feedback will be collected and analysed to find the overall usefulness of video. DISCUSSION: If it becomes apparent that this video intervention is successful in raising awareness of PPD among postpartum mothers and reducing stigma, it can be used to aid early identification of mothers with PPD which can result in early management and improved health outcome for both mothers and children. The major goals of the video intervention are to raise awareness, lessen stigma, and prevent PPD through strong family support, adopting healthy lifestyles, having access to information, practising self-care, and enhancing help-seeking. TRIAL REGISTRATION: The trial is registered under the Clinical Trial Registry- India (CTRI) (CTRI/2023/03/050836). The current study adheres to the SPIRIT Guidelines [See S1 Checklist: SPIRIT Guidelines].

Superior protection in a relapsing Plasmodium cynomolgi rhesus macaque model by a chemoprophylaxis with sporozoite immunization regimen with atovaquone-proguanil followed by primaquine.

BACKGROUND: To gain a deeper understanding of protective immunity against relapsing malaria, this study examined sporozoite-specific T cell responses induced by a chemoprophylaxis with sporozoite (CPS) immunization in a relapsing Plasmodium cynomolgi rhesus macaque model. METHODS: The animals received three CPS immunizations with P. cynomolgi sporozoites, administered by mosquito bite, while under two anti-malarial drug regimens. Group 1 (n = 6) received artesunate/chloroquine (AS/CQ) followed by a radical cure with CQ plus primaquine (PQ). Group 2 (n = 6) received atovaquone-proguanil (AP) followed by PQ. After the final immunization, the animals were challenged with intravenous injection of 104 P. cynomolgi sporozoites, the dose that induced reliable infection and relapse rate. These animals, along with control animals (n = 6), were monitored for primary infection and subsequent relapses. Immunogenicity blood draws were done after each of the three CPS session, before and after the challenge, with liver, spleen and bone marrow sampling and analysis done after the challenge. RESULTS: Group 2 animals demonstrated superior protection, with two achieving protection and two experiencing partial protection, while only one animal in group 1 had partial protection. These animals displayed high sporozoite-specific IFN-γ T cell responses in the liver, spleen, and bone marrow after the challenge with one protected animal having the highest frequency of IFN-γ+ CD8+, IFN-γ+ CD4+, and IFN-γ+ γδ T cells in the liver. Partially protected animals also demonstrated a relatively high frequency of IFN-γ+ CD8+, IFN-γ+ CD4+, and IFN-γ+ γδ T cells in the liver. It is important to highlight that the second animal in group 2, which experienced protection, exhibited deficient sporozoite-specific T cell responses in the liver while displaying average to high T cell responses in the spleen and bone marrow. CONCLUSIONS: This research supports the notion that local liver T cell immunity plays a crucial role in defending against liver-stage infection. Nevertheless, there is an instance where protection occurs independently of T cell responses in the liver, suggesting the involvement of the liver's innate immunity. The relapsing P. cynomolgi rhesus macaque model holds promise for informing the development of vaccines against relapsing P. vivax.

Second booster dose improves antibody neutralization against BA.1, BA.5 and BQ.1.1 in individuals previously immunized with CoronaVac plus BNT162B2 booster protocol.

Introduction: SARS-CoV-2 vaccines production and distribution enabled the return to normalcy worldwide, but it was not fast enough to avoid the emergence of variants capable of evading immune response induced by prior infections and vaccination. This study evaluated, against Omicron sublineages BA.1, BA.5 and BQ.1.1, the antibody response of a cohort vaccinated with a two doses CoronaVac protocol and followed by two heterologous booster doses. Methods: To assess vaccination effectiveness, serum samples were collected from 160 individuals, in 3 different time points (9, 12 and 18 months after CoronaVac protocol). For each time point, individuals were divided into 3 subgroups, based on the number of additional doses received (No booster, 1 booster and 2 boosters), and a viral microneutralization assay was performed to evaluate neutralization titers and seroconvertion rate. Results: The findings presented here show that, despite the first booster, at 9m time point, improved neutralization level against omicron ancestor BA.1 (133.1 to 663.3), this trend was significantly lower for BQ.1.1 and BA.5 (132.4 to 199.1, 63.2 to 100.2, respectively). However, at 18m time point, the administration of a second booster dose considerably improved the antibody neutralization, and this was observed not only against BA.1 (2361.5), but also against subvariants BQ.1.1 (726.1) and BA.5 (659.1). Additionally, our data showed that, after first booster, seroconvertion rate for BA.5 decayed over time (93.3% at 12m to 68.4% at 18m), but after the second booster, seroconvertion was completely recovered (95% at 18m). Discussion: Our study reinforces the concerns about immunity evasion of the SARS-CoV-2 omicron subvariants, where BA.5 and BQ.1.1 were less neutralized by vaccine induced antibodies than BA.1. On the other hand, the administration of a second booster significantly enhanced antibody neutralization capacity against these subvariants. It is likely that, as new SARS-CoV-2 subvariants continue to emerge, additional immunizations will be needed over time.

Coverage of BCG Vaccination for children aged until 7 years old and its determinants in French Guiana.

INTRODUCTION: The overall incidence of tuberculosis (TB) in France is low; thus, BCG vaccination is no longer mandatory. In French Guiana - a French overseas territory - BCG vaccination is strongly recommended because the incidence of TB is high in the context of mass immigration from endemic countries with low BCG vaccination rates. Thus, it is important to assess Bacillus Calmette-Guérin (BCG) vaccination coverage and its predictors. METHODS: We used data from the 2014 French Guiana Yellow Fever survey, which was conducted by the Observatoire Régional de la Santé de Guyane. Demographic and immunization data from eligible children and their families were collected using a questionnaire. Children who had an immunization card and who were no older than 7 years of age at the time of the survey were eligible. The Coverage for BCG and other mandatory vaccines were estimated; the delay in BCG vaccination was also computed. Univariate and multivariate analyses identified predictors associated with BCG immunization and BCG delayed immunization (after 2 months of age). RESULTS AND CONCLUSION: Overall, 469 children were eligible for this study. The total BCG coverage was 79.5 %, and the proportion of children vaccinated with delay was 50.7 %. The multivariate analysis indicated that BCVA was significantly greater among children younger than 3 years of age, whose household head was employed and whose education level was greater. None of the predictors were associated with the delay of BCG vaccination.

Peak transgene expression after intramuscular immunization of mice with adenovirus 26-based vector vaccines correlates with transgene-specific adaptive immune responses.

Non-replicating adenovirus-based vectors have been broadly used for the development of prophylactic vaccines in humans and are licensed for COVID-19 and Ebola virus disease prevention. Adenovirus-based vectored vaccines encode for one or more disease specific transgenes with the aim to induce protective immunity against the target disease. The magnitude and duration of transgene expression of adenovirus 5- based vectors (human type C) in the host are key factors influencing antigen presentation and adaptive immune responses. Here we characterize the magnitude, duration, and organ biodistribution of transgene expression after single intramuscular administration of adenovirus 26-based vector vaccines in mice and evaluate the differences with adenovirus 5-based vector vaccine to understand if this is universally applicable across serotypes. We demonstrate a correlation between peak transgene expression early after adenovirus 26-based vaccination and transgene-specific cellular and humoral immune responses for a model antigen and SARS-CoV-2 spike protein, independent of innate immune activation. Notably, the memory immune response was similar in mice immunized with adenovirus 26-based vaccine and adenovirus 5-based vaccine, despite the latter inducing a higher peak of transgene expression early after immunization and a longer duration of transgene expression. Together these results provide further insights into the mode of action of adenovirus 26-based vector vaccines.

Surveillance for adverse events following immunization with DTaP-containing combination vaccines in Linping, China, 2019-2022.

Background: The DTaP-Hib and DTaP-IPV/Hib combination vaccine can be used as a substitute for the diphtheria, tetanus, and acellular pertussis combined vaccine (DTaP). We aimed to evaluate the safety of multi-component vaccines containing DTaP by analyzing the reporting rates and characteristics of adverse events following immunization (AEFIs) in Linping District during the years 2019 to 2022. Methods: We obtained data of AEFI and vaccination from the National AEFI Surveillance System of China and Zhejiang Municipal Immunization Information Management System, respectively, during 2019-2022 for a descriptive, epidemiological analysis. Results: The total number of AEFI reported following vaccinations with DTaP-containing combination vaccines was 802 in Linping District from 2019 to 2022. The overall reporting rates of AEFIs following DTaP, DTaP-Hib, and DTaP-IPV/Hib vaccinations were 445.72 (537 cases), 536.29 (45 cases), and 306.13 (220 cases) per 100,000 doses in Linping District from 2019 to 2022, respectively. Only one case of a serious AEFI following DTaP vaccination, with a reporting rate of 0.83 per 100,000 doses. The composition ratio of vaccine product-related reactions for DTaP, DTaP-Hib, and DTaP-IPV/Hib were 99.81, 97.78, and 100.00%, respectively. The composition ratio of coincidental events for DTaP and DTaP-Hib were 0.19 and 2.22%, respectively. The reporting rates of total AEFIs for DTaP-IPV/Hib were lower than for DTaP. The reporting rate of local induration for DTaP-Hib was lower than for DTaP, and the reporting rates of local redness & swelling and local induration for DTaP-IPV/Hib were both lower than for DTaP. DTaP-IPV/Hib had a higher proportion of AEFIs in first quarter compared to DTaP. The reporting rate after the second dose of DTaP-Hib was higher than that of DTaP, and the reporting rates of AEFIs after the first dose and third dose of DTaP-IPV/Hib were lower than DTaP. Conclusion: The reported AEFIs to multi-component vaccines containing DTaP components during 2019-2022 in Linping District were mainly mild vaccine reactions. DTaP-containing combination vaccines demonstrated a good safety profile.