Predictors of parental acceptance to live attenuated influenza vaccine for children.

To determine the influencing factors of Chinese parents' intention and behavior for children to receive live attenuated influenza vaccine during the 2022-2023 influenza season. A theoretical model was developed and included seven constructs, and structural equation modeling was used to test 11 hypotheses. From October 2022 to December 2023, a survey was conducted across 38 medical institutions in four Chinese cities and their subordinate districts, counties, and rural areas. Parents who accompanied their children for vaccinations were selected through a randomization process based on their child's medical card numbers. Measures were taken to minimize method bias, including a diverse geographical representation and random sampling. The survey resulted in the collection of 936 valid responses, exceeding the recommended sample size for structural equation model analysis and providing robust statistical inferences. During the study period, 936 respondents were included in the study. Perceived ease of use was verified to be a predictor of perceived usefulness and perceived value. Perceived usefulness was verified as a predictor of perceived value and behavioral intention. Knowledge was a significant antecedent of perceived value and risk perception of influenza disease. Risk perception of influenza disease was proved to be a significant predictor of perceived value and self-reported vaccination behavior. Perceived value significantly affected behavioral intention, and behavioral intention significantly affected self-reported vaccination behavior. Six demographic variables significantly moderate the theoretical models. The low vaccination coverage of live attenuated influenza vaccine (LAIV) among children in China suggests a need for a deeper understanding of the factors that influence vaccination rates. Particularly, effective strategies are necessary from policymakers and practitioners to elevate childhood LAIV coverage.

Quadrivalent Live-Attenuated Influenza Vaccine in Milan preschools: an Italian experience of school-located flu vaccination within the 2022-2023 season.

BACKGROUND: In Italy, since the 2020-2021 flu season, the flu vaccine recommendation was extended to all children aged 6 months to 6 years and quadrivalent Live-Attenuated Influenza Vaccine (qLAIV) was introduced. Since school-aged children are important carriers of annual influenza epidemics, a school-based influenza vaccination program may potentially increase vaccine uptake. Recent studies, conducted in the UK and the US, show that school-based vaccination can reach higher percentage of paediatric vaccination coverage compared to children vaccinated in other settings. METHODS: During 2022-2023 flu season in 9 preschools located in Milan healthcare personnel vaccinated children with qLAIV at the end of a school day. A Google Form questionnaire was administered to preschoolers' parents of all preschools within the Municipality of Milan. RESULTS: In the preschools engaged in the vaccination program, 233 out of 1939 children were vaccinated (12%). Among these, 61 (26.2%) had never been vaccinated for influenza before. Vaccination coverage was 11.5% for Italian children and 14.3% for children coming from an immigrant background. We collected 3659 questionnaire responses, divided according to study participation status (371 from preschools that participated in the vaccination program and 3288 from other preschools in Milan). 57% of the families who answered to the questionnaire vaccinated their children for flu. qLAIV accounted for 85.6% of vaccinations. We observed a statistically significant difference in the percentage of vaccinated children between those attending a school participating in the project (67.9%) and children attending other schools (56%) (p < 0.001). Vaccination was administered by family pediatricians (48.9%), in vaccination centers (34.8%), in vaccine hubs (11.3%), in schools (2.6%), by private pediatricians (1.6%) and in other settings (0.7%). Focusing on the responses from families whose children attend schools participating in the vaccination program, 21.8% stated that the vaccination was provided in school. CONCLUSION: According to our experience, in Italy, at the moment, only the cooperation between health providers and alternative settings, including schools, may expand flu vaccination coverage. In particular, schools are to be considered a place to inform and reach out to families, useful to increase vaccination coverage.

[Dengue vaccines, a time for cautious optimism?] / Vaccins contre la dengue, le temps de l'optimisme prudent ?

Vaccine could take a central role in the strategy to reduce the burden of dengue. The development of an effective and safe vaccine must address various immunological challenges. Several vaccines are currently in development. To date, two live-attenuated vaccines have been deployed. Both have an effectiveness that varies depending on the serotypes. The deployment of the Dengvaxia vaccine, which began in 2015, was marked by a major safety alert leading to its use being restricted to previously dengue-seropositive people over 9 years old. The Qdenga vaccine is currently being deployed. There is for now insufficient data to ensure its safety in seronegative people. Some travelers, who have previously been infected with dengue, are a group for whom a vaccination recommendation applies.

Les vaccins pourraient occuper une place centrale dans la stratégie de réduction du fardeau de la dengue. Le développement d'un vaccin efficace et sûr est complexe car il doit relever plusieurs défis immunologiques. Différents vaccins sont en développement. À ce jour, deux vaccins vivants atténués ont été déployés. Tous deux ont une efficacité qui varie selon les sérotypes. Le déploiement du vaccin Dengvaxia, débuté en 2015, a été marqué par une alerte de sécurité majeure conduisant à restreindre son usage aux personnes de plus de 9 ans, préalablement séropositives pour la dengue. Le vaccin Qdenga est en cours de déploiement. Le recul est insuffisant pour assurer son innocuité chez les séronégatifs. Certains voyageurs, ayant déjà été infectés par la dengue, constituent un groupe pour lequel une recommandation vaccinale s'applique.

Safety and Efficacy of the Modified Vaccinia Ankara-Bavaria Nordic Vaccine Against Mpox in the Real World: Systematic Review and Meta-Analysis.

In May 2022, mpox began to spread worldwide, posing a serious threat to human public health. Modified Vaccinia Ankara-Bavaria Nordic (MVA-BN) is a live attenuated orthopoxvirus vaccine that has been authorized by the U.S. Food and Drug Administration as the vaccine of choice for the prevention of mpox. In this study, we conducted a meta-analysis of all currently published literature on the efficacy and safety of the MVA-BN vaccine in the real world, showing that the MVA-BN vaccine is effective and safe, with efficacy of up to 75% with a single dose and up to 80% with a two-dose vaccine. Meanwhile, we found that subcutaneous injection has lower local and systemic adverse events than intradermal injection, regardless of single- or two-dose vaccination, and subcutaneous injection is better tolerated in children, the elderly, or people with underlying medical conditions. These results have important reference value for clinical practice.

Protective immunity induced through two calving seasons following administration of live epizootic bovine abortion agent (EBAA) vaccine.

A live, infectious vaccine candidate for epizootic bovine abortion, designated EBAA Vaccine, USDA-APHIS Product code #1544.00, has been reported to be both safe and effective. Previous studies established that a single dose of EBAA vaccine administered to cows at potencies of either 2000 or 500 live P. abortibovis-infected murine spleen cells (P.a.-LIC) induced protective immunity for a minimum of 5 months. The current study employed 19 pregnant cows that were challenged with P. abortibovis in their 2nd trimester of gestation; 9 were vaccinated 17.2-months earlier as 1-year-olds with 2000 P.a.-LIC and 10 served as negative controls. Eighty-nine percent of the vaccinates gave birth to healthy calves as compared to 10% of challenge controls. Vaccine efficacy was significant when analyzed by prevented fractions (87.7%; 95% CI=0.4945-0.9781). Serologic data supports previous findings that pregnant cows with detectable P. abortibovis antibodies are immune to P. abortibovis challenge as demonstrated by the birth of healthy calves.

Immune responses associated with protection induced by chemoattenuated PfSPZ vaccine in malaria-naive Europeans.

Vaccination of malaria-naive volunteers with a high dose of Plasmodium falciparum sporozoites chemoattenuated by chloroquine (CQ) (PfSPZ-CVac [CQ]) has previously demonstrated full protection against controlled human malaria infection (CHMI). However, lower doses of PfSPZ-CVac [CQ] resulted in incomplete protection. This provides the opportunity to understand the immune mechanisms needed for better vaccine-induced protection by comparing individuals who were protected with those not protected. Using mass cytometry, we characterized immune cell composition and responses of malaria-naive European volunteers who received either lower doses of PfSPZ-CVac [CQ], resulting in 50% protection irrespective of the dose, or a placebo vaccination, with everyone becoming infected following CHMI. Clusters of CD4+ and γδ T cells associated with protection were identified, consistent with their known role in malaria immunity. Additionally, EMRA CD8+ T cells and CD56+CD8+ T cell clusters were associated with protection. In a cohort from a malaria-endemic area in Gabon, these CD8+ T cell clusters were also associated with parasitemia control in individuals with lifelong exposure to malaria. Upon stimulation with P. falciparum-infected erythrocytes, CD4+, γδ, and EMRA CD8+ T cells produced IFN-γ and/or TNF, indicating their ability to mediate responses that eliminate malaria parasites.

Brucella melitensis Rev1Δwzm: Placental pathogenesis studies and safety in pregnant ewes.

One of the main causes of human brucellosis is Brucella melitensis infecting small ruminants. To date, Rev1 is the only vaccine successfully used to control ovine and caprine brucellosis. However, it is pathogenic for pregnant animals, resulting in abortions and vaginal and milk shedding, as well as being infectious for humans. Therefore, there is an urgent need to develop an effective vaccine that is safer than Rev1. In efforts to further attenuate Rev1, we recently used wzm inactivation to generate a rough mutant (Rev1Δwzm) that retains a complete antigenic O-polysaccharide in the bacterial cytoplasm. The aim of the present study was to evaluate the placental pathogenicity of Rev1Δwzm in trophoblastic cells, throughout pregnancy in mice, and in ewes inoculated in different trimesters of pregnancy. This mutant was evaluated in comparison with the homologous 16MΔwzm derived from a virulent strain of B. melitensis and the naturally rough sheep pathogen B. ovis. Our results show that both wzm mutants triggered reduced cytotoxic, pro-apoptotic, and pro-inflammatory signaling in Bewo trophoblasts, as well as reduced relative expression of apoptosis genes. In mice, both wzm mutants produced infection but were rapidly cleared from the placenta, in which only Rev1Δwzm induced a low relative expression of pro-apoptotic and pro-inflammatory genes. In the 66 inoculated ewes, Rev1Δwzm was safe and immunogenic, displaying a transient serological interference in standard RBT but not CFT S-LPS tests; this serological response was minimized by conjunctival administration. In conclusion, these results support that B. melitensis Rev1Δwzm is a promising vaccine candidate for use in pregnant ewes and its efficacy against B. melitensis and B. ovis infections in sheep warrants further study.

Live-attenuated CHIKV vaccine with rearranged genome replicates in vitro and induces immune response in mice.

Chikungunya fever virus (CHIKV) is a mosquito-borne alphavirus that causes wide-spread human infections and epidemics in Asia, Africa and recently, in the Americas. CHIKV is considered a priority pathogen by CEPI and WHO. Despite recent approval of a live-attenuated CHIKV vaccine, development of additional vaccines is warranted due to the worldwide outbreaks of CHIKV. Previously, we developed immunization DNA (iDNA) plasmid capable of launching live-attenuated CHIKV vaccine in vivo. Here we report the use of CHIKV iDNA plasmid to prepare a novel, live-attenuated CHIKV vaccine V5040 with rearranged RNA genome. In V5040, genomic RNA was rearranged to encode capsid gene downstream from the glycoprotein genes. Attenuated mutations derived from experimental CHIKV 181/25 vaccine were also engineered into E2 gene of V5040. The DNA copy of rearranged CHIKV genomic RNA with attenuated mutations was cloned into iDNA plasmid pMG5040 downstream from the CMV promoter. After transfection in vitro, pMG5040 launched replication of V5040 virus with rearranged genome and attenuating E2 mutations. Furthermore, V5040 virus was evaluated in experimental murine models for general safety and immunogenicity. Vaccination with V5040 virus subcutaneously resulted in elicitation of CHIKV-specific, virus-neutralizing antibodies. The results warrant further evaluation of V5040 virus with rearranged genome as a novel live-attenuated vaccine for CHIKV.

Post-marketing surveillance of 10,392 herpes zoster vaccines doses in Australia.

BACKGROUND: Immunisation against herpes zoster is recommended for adults aged ≥ 50 years. Two vaccines, a live attenuated (ZVL, Zostavax®) and an adjuvant recombinant subunit (HZ/su, Shingrix®), are available in Australia. Immunisation guidelines are shifting their recommendations towards HZ/su because of higher efficacy in preventing herpes zoster and associated complications. However, there are limited post-marketing data comparing the safety profiles of these vaccines. METHODS: Data from SmartVax, an active surveillance system for monitoring adverse events following immunisation (AEFIs) utilised by > 450 clinics throughout Australia, were analysed. Data from patients aged ≥ 50 years, who received ZVL or HZ/su, from 1 June 2021 to 31 May 2022, at clinics that utilised SmartVax were included. The proportion of records where patients who reported any, local, and systemic AEFIs after receiving ZVL or HZ/su were compared using multivariable logistic regression models. RESULTS: Data from 10,392 immunisation records (n = 8341 ZVL; n = 2051 HZ/su) were included. The proportion of AEFIs reported was higher with HZ/su (41.9 % [any], 33.8 % [local], 25.2 % [systemic]) than with ZVL (8.7 % [any], 6.2 % [local], 3.5 % [systemic]). After controlling for demographic variables, HZ/su presented a 6-fold increase in the odds (OR 6.44; 95 %CI: 5.57-7.46) of a reported AEFI compared to ZVL. Only 59 (0.6 %) of vaccinations lead to medical attention being sought due to an AEFI. CONCLUSIONS: While rates of AEFIs was higher with HZ/su than ZVL, most AEFIs were mild and did not require medical attention. Our findings support the change in vaccine recommendations and the use of HZ/su in immunisation programs.

Mucosal prime-boost immunization with live murine pneumonia virus-vectored SARS-CoV-2 vaccine is protective in macaques.

Immunization via the respiratory route is predicted to increase the effectiveness of a SARS-CoV-2 vaccine. Here, we evaluate the immunogenicity and protective efficacy of one or two doses of a live-attenuated murine pneumonia virus vector expressing SARS-CoV-2 prefusion-stabilized spike protein (MPV/S-2P), delivered intranasally/intratracheally to male rhesus macaques. A single dose of MPV/S-2P is highly immunogenic, and a second dose increases the magnitude and breadth of the mucosal and systemic anti-S antibody responses and increases levels of dimeric anti-S IgA in the airways. MPV/S-2P also induces S-specific CD4+ and CD8+ T-cells in the airways that differentiate into large populations of tissue-resident memory cells within a month after the boost. One dose induces substantial protection against SARS-CoV-2 challenge, and two doses of MPV/S-2P are fully protective against SARS-CoV-2 challenge virus replication in the airways. A prime/boost immunization with a mucosally-administered live-attenuated MPV vector could thus be highly effective in preventing SARS-CoV-2 infection and replication.

Immunogenicity and safety of live attenuated and recombinant/inactivated varicella zoster vaccines in people living with HIV: A systematic review.

Few papers focus their attention on VZV vaccination effectiveness among people living with HIV (PLWH). Flanking the live attenuated vaccine (VZL) available, a newly recombinant vaccine (RZV) was recently introduced and approved for HZ prevention among adults. PLWH represents a population on which a particular attention should be applied, in order to guarantee the vaccine efficacy and safety. We performed a literature search in USNLM, PubMed, PubMed Central, PMC and Cochrane Library. From all the publications found eligible, data were extracted and processed per population, vaccine type, immunogenicity and ADRs. The review of the 13 included studies shows that both RZV and VZL are immunogenic and have an acceptable safety profile in adults and children living with HIV. However, given the lack of research available about vaccine efficacy in preventing VZV and HZ in PLWH, additional studies need to be performed, in order to achieve a full completeness of data.

Innate immune activation restricts priming and protective efficacy of the radiation-attenuated PfSPZ malaria vaccine.

A systems analysis was conducted to determine the potential molecular mechanisms underlying differential immunogenicity and protective efficacy results of a clinical trial of the radiation-attenuated whole-sporozoite PfSPZ vaccine in African infants. Innate immune activation and myeloid signatures at prevaccination baseline correlated with protection from P. falciparum parasitemia in placebo controls. These same signatures were associated with susceptibility to parasitemia among infants who received the highest and most protective PfSPZ vaccine dose. Machine learning identified spliceosome, proteosome, and resting DC signatures as prevaccination features predictive of protection after highest-dose PfSPZ vaccination, whereas baseline circumsporozoite protein-specific (CSP-specific) IgG predicted nonprotection. Prevaccination innate inflammatory and myeloid signatures were associated with higher sporozoite-specific IgG Ab response but undetectable PfSPZ-specific CD8+ T cell responses after vaccination. Consistent with these human data, innate stimulation in vivo conferred protection against infection by sporozoite injection in malaria-naive mice while diminishing the CD8+ T cell response to radiation-attenuated sporozoites. These data suggest a dichotomous role of innate stimulation for malaria protection and induction of protective immunity by whole-sporozoite malaria vaccines. The uncoupling of vaccine-induced protective immunity achieved by Abs from more protective CD8+ T cell responses suggests that PfSPZ vaccine efficacy in malaria-endemic settings may be constrained by opposing antigen presentation pathways.

Investigation of the safety and protective efficacy of an attenuated and marker M. bovis-BoHV-1 combined vaccine in bovines.

Bovine respiratory disease (BRD) is one of the most common diseases in the cattle industry worldwide; it is caused by multiple bacterial or viral coinfections, of which Mycoplasma bovis (M. bovis) and bovine herpesvirus type 1 (BoHV-1) are the most notable pathogens. Although live vaccines have demonstrated better efficacy against BRD induced by both pathogens, there are no combined live and marker vaccines. Therefore, we developed an attenuated and marker M. bovis-BoHV-1 combined vaccine based on the M. bovis HB150 and BoHV-1 gG-/tk- strain previously constructed in our lab and evaluated in rabbits. This study aimed to further evaluate its safety and protective efficacy in cattle using different antigen ratios. After immunization, all vaccinated cattle had a normal rectal temperature and mental status without respiratory symptoms. CD4+, CD8+, and CD19+ cells significantly increased in immunized cattle and induced higher humoral and cellular immune responses, and the expression of key cytokines such as IL-4, IL-12, TNF-α, and IFN-γ can be promoted after vaccination. The 1.0 × 108 CFU of M. bovis HB150 and 1.0 × 106 TCID50 BoHV-1 gG-/tk- combined strain elicited the most antibodies while significantly increasing IgG and cellular immunity after challenge. In conclusion, the M. bovis HB150 and BoHV-1 gG-/tk- combined strain was clinically safe and protective in calves; the mix of 1.0 × 108 CFU of M. bovis HB150 and 1.0 × 106 TCID50 BoHV-1 gG-/tk- strain was most promising due to its low amount of shedding and highest humoral and cellular immune responses compared with others. This study introduces an M. bovis-BoHV-1 combined vaccine for application in the cattle industry.

A live attenuated influenza B virus vaccine expressing RBD elicits protective immunity against SARS-CoV-2 in mice.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a significant threat to human health globally. It is crucial to develop a vaccine to reduce the effect of the virus on public health, economy, and society and regulate the transmission of SARS-CoV-2. Influenza B virus (IBV) can be used as a vector that does not rely on the current circulating influenza A strains. In this study, we constructed an IBV-based vector vaccine by inserting a receptor-binding domain (RBD) into a non-structural protein 1 (NS1)-truncated gene (rIBV-NS110-RBD). Subsequently, we assessed its safety, immunogenicity, and protective efficacy against SARS-CoV-2 in mice, and observed that it was safe in a mouse model. Intranasal administration of a recombinant rIBV-NS110-RBD vaccine induced high levels of SARS-CoV-2-specific IgA and IgG antibodies and T cell-mediated immunity in mice. Administering two doses of the intranasal rIBV-NS110-RBD vaccine significantly reduced the viral load and lung damage in mice. This novel IBV-based vaccine offers a novel approach for controlling the SARS-CoV-2 pandemic.

No vaccine interference between bovine coronavirus and bovine herpesvirus-1 in a randomized trial when coadministrating two intranasal modified-live viral vaccines to neonatal calves.

OBJECTIVE: Compare immune responses induced by 2 commercial intranasal (IN) modified-live viral (MLV) vaccines given individually or coadministered and evaluate prevention of infection and lung pathology following bovine herpesvirus-1 (BHV-1) challenge. ANIMALS: 36 male Holstein calves (ages, 5 to 12 days). METHODS: In a randomized complete block design, each calf received an IN injection of either vaccine diluent (Placebo), an MLV vaccine containing bovine herpesvirus-1 (BHV-1; N3), bovine coronavirus vaccine (BC), or both N3 and BC (BC + N3) with a booster 4 weeks later. Nasal secretions and blood were collected weekly. Three weeks after the booster, the calves were challenged with BHV-1, sampled for virus shedding, and euthanized 10 days later to quantify lung pathology. The study period was September 7, 2020, to April 6, 2021. RESULTS: Calves were seropositive for BHV-1 and BC before vaccination. No significant difference in BC-specific serum immunoglobin G and nasal immunoglobin A antibody responses in the BC versus BC + N3 group or BHV-1-specific serum immunoglobin G and nasal immunoglobin A antibody responses in the N3 versus BC + N3 group. Cytokine responses to BHV-1 and BC did not differ among groups. BHV-1 shedding after challenge was significantly reduced in N3 groups versus Placebo and BC. There was a significant reduction in lung pathology in the N3 + BC group versus Placebo. CLINICAL RELEVANCE: This study provides evidence an MLV vaccine containing BHV-1 and an MLV BC vaccine can be coadministered to neonatal calves without significantly altering immune responses to the 2 viruses or compromising the prevention of BHV-1 respiratory disease. Calves receiving the BC + N3 vaccine had a significant reduction in lung pathology after BHV-1 aerosol challenge.

Live vaccinations in dermatology for immunosuppressed patients: a narrative review.

Given the higher susceptibility to infectious disease in patients receiving immunosuppressive therapies for inflammatory dermatologic conditions, immunization is important in this population. While live vaccines protect against life-threatening diseases, they can be harmful in immunosuppressed patients given the risk of replication of the attenuated pathogen and adverse reactions. The utilization of live vaccines in immunosuppressed patients depends on multiple factors such as the vaccine and therapy regimen. To provide an overview of evidence-based recommendations for the use of live vaccines in patients receiving immunosuppressive therapies for dermatological conditions. A literature search of the PubMed database was performed using keywords live vaccine, live-attenuated vaccine, dermatology, immunosuppressed, and immunocompromised, and specific immunosuppressive therapies: corticosteroids, glucocorticoids, methotrexate, azathioprine, cyclosporine, mycophenolate mofetil, biologics. Relevant articles written in English were included. Using these keywords, 125 articles were reviewed, of which 28 were ultimately selected. Recommendations for live vaccines can be determined on a case-by-case basis. Measles, mumps, rubella, varicella (MMRV) vaccines may be safely administered to patients on low-dose immunosuppressive agents while the yellow fever vaccine is typically contraindicated. It may be safe to administer live MMRV boosters to children on immunosuppressive therapies and the live herpes zoster vaccine to patients on biologics. Given poor adherence to immunization guidelines in immunosuppressed patients, dermatologists have a critical role in educating patients and general practitioners regarding live vaccines. By reviewing a patient's vaccination history and following immunization guidelines prior to initiating immunosuppressive therapies, physicians can mitigate morbidity and mortality from vaccine-preventable diseases.

Effectiveness of JYNNEOS Vaccine Against Diagnosed Mpox Infection - New York, 2022.

In 2022, an international Monkeypox virus outbreak, characterized by transmission primarily through sexual contact among gay, bisexual, and other men who have sex with men (MSM), resulted in 375 monkeypox (mpox) cases in the state of New York outside of New York City (NYC).*,† The JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic), licensed by the U.S. Food and Drug Administration (FDA) against mpox as a 2-dose series, with doses administered 4 weeks apart,§ was deployed in a national vaccination campaign.¶ Before this outbreak, evidence to support vaccine effectiveness (VE) against mpox was based on human immunologic and animal challenge studies (1-3). New York State Department of Health (NYSDOH) conducted a case-control study to estimate JYNNEOS VE against diagnosed mpox in New York residents outside of NYC, using data from systematic surveillance reporting. A case-patient was defined as a man aged ≥18 years who received a diagnosis of mpox during July 24-October 31, 2022. Contemporaneous control patients were men aged ≥18 years with diagnosed rectal gonorrhea or primary syphilis and a history of male-to-male sexual contact, without mpox. Case-patients and control patients were matched to records in state immunization systems. JYNNEOS VE was estimated as 1 - odds ratio (OR) x 100, and JYNNEOS vaccination status (vaccinated versus unvaccinated) at the time of diagnosis was compared, using conditional logistic regression models that adjusted for week of diagnosis, region, patient age, and patient race and ethnicity. Among 252 eligible mpox case-patients and 255 control patients, the adjusted VE of 1 dose (received ≥14 days earlier) or 2 doses combined was 75.7% (95% CI = 48.5%-88.5%); the VE for 1 dose was 68.1% (95% CI = 24.9%-86.5%) and for 2 doses was 88.5% (95% CI = 44.1%-97.6%). These findings support recommended 2-dose JYNNEOS vaccination consistent with CDC and NYSDOH guidance.

Effect of monovalent and bivalent live attenuated vaccines against QX-like IBV infection in young chickens.

Since 1999, QX-like (GI-19) avian infectious bronchitis viruses have been the predominant strains in China till now. Vaccination is the most effective way to control the disease, while live attenuated vaccine is widely used. In the current research, we evaluated the effect of several monovalent and bivalent live IBV vaccines in young chickens against the QX-like (GI-19) IBV infection. The results showed that monovalent 4/91 and bivalent Ma5+LDT3 vaccines could provide efficient protection in day-old chickens that reduced morbidity and mortality, ameliorated histopathology lesions, and reduced viral loads were observed. These data suggest that vaccination through nasal route with monovalent 4/91 or bivalent Ma5+LDT3 in day-old chickens could serve a safe and effective vaccination strategy for controlling QX-like (GI-19) infectious bronchitis virus.

Timing of Live Attenuated Vaccination in Infants Exposed to Infliximab or Adalimumab in Utero: A Prospective Cohort Study in 107 Children.

BACKGROUND AND AIMS: For infants exposed in utero to anti-tumour necrosis factor-α [TNF] medications, it is advised that live-attenuated vaccinations be postponed until the drug is cleared, but little is known about time to clearance. To minimize delays before live-attenuated vaccination can be given, we aimed to develop a pharmacokinetic model to predict time-to-clearance in infants exposed during pregnancy. METHODS: We prospectively followed in utero infliximab/adalimumab-exposed infants of mothers with inflammatory bowel disease across four countries between 2011 and 2018. Infants with a detectable anti-TNF umbilical-cord level and at least one other blood sample during the first year of life were included. RESULTS: Overall, 107 infants were enrolled, including 166 blood samples from 71 infliximab-exposed infants and 77 samples from 36 adalimumab-exposed infants. Anti-TNF was detectable in 23% [n = 25] of infants at 6 months. At 12 months, adalimumab was not detected but 4% [n = 3] had detectable infliximab. A Bayesian forecasting method was developed using a one-compartment pharmacokinetic model. Model validation showed that the predicted clearing time was in accordance with the measured observations. A clinician-friendly online calculator was developed for calculating full anti-TNF clearing time: https://xiaozhu.shinyapps.io/antiTNFcalculator2/. CONCLUSIONS: Almost one-quarter of infants born to mothers receiving anti-TNF during pregnancy have detectable anti-TNF at 6 months. To limit the time to live-attenuated vaccination in infants of mothers receiving anti-TNF during pregnancy, the results of a cord drug level at birth and a second sample ≥ 1 month thereafter can be used to estimate the time for full anti-TNF clearance in these children.