Bacillus Calmette-Guerin Vaccine-Associated Lymphadenitis in Children

Background: Tuberculosis (TB) is one of the most important infectious diseases worldwide. Bacillus Calmette-Guerin (BCG) is a live attenuated vaccine, entered into the childhood immunization program by the World Health Organization (WHO) in 1974 to prevent TB. One of the relatively common complications of BCG vaccination is regional lymphadenitis. Objectives: This study aimed to determine the lymphadenitis incidence in BCG-vaccinated children in southwest Iran. Methods: In a prospective descriptive study, infants born from March to June 2017 were evaluated for BCG vaccine complications at two, four, six, nine, and 12 months of age in Ahvaz, southwestern Iran. Results: The study enrolled 1,506 infants (794 males and 712 females). Among the vaccinated infants, four (0.26%) had injection site reactions, and 106 (7.03%) presented lymphadenitis (66 males and 40 females). The lymphadenitis rate was significantly higher in males than in females (P = 0.024). The mean age at presentation was 4.28 ± 0.79 months. Suppurative lymphadenitis was seen in 53 (50%) cases and nonsuppurative lymphadenitis in 53 (50%) cases. About 80% of nonsuppurative lymphadenitis resolved entirely or partially after a one-year follow-up. Of 53 cases with suppurative lymphadenitis, 46 (43.4%) developed spontaneous drainage, and seven (6.6%) were drained by needle aspiration. No significant relationship was found between the BCG inoculation site and lymphadenitis rate. No other complications such as osteomyelitis or disseminated BCG infection were observed after one year of follow-up. Conclusions: The relatively high incidence of BCG lymphadenitis in this study may be due to the vaccine strain, young vaccinees, and improper vaccination techniques. In most cases, nonsuppurative lymphadenitis regressed spontaneously, and suppurative lymphadenitis was drained spontaneously or by needle aspiration.

PglB function and glycosylation efficiency is temperature dependent when the pgl locus is integrated in the Escherichia coli chromosome

Background Campylobacter is an animal and zoonotic pathogen of global importance, and a pressing need exists for effective vaccines, including those that make use of conserved polysaccharide antigens. To this end, we adapted Protein Glycan Coupling Technology (PGCT) to develop a versatile Escherichia coli strain capable of generating multiple glycoconjugate vaccine candidates against Campylobacter jejuni. Results We generated a glycoengineering E. coli strain containing the conserved C. jejuni heptasaccharide coding region integrated in its chromosome as a model glycan. This methodology confers three advantages: (i) reduction of plasmids and antibiotic markers used for PGCT, (ii) swift generation of many glycan-protein combinations and consequent rapid identification of the most antigenic proteins or peptides, and (iii) increased genetic stability of the polysaccharide coding-region. In this study, by using the model glycan expressing strain, we were able to test proteins from C. jejuni, Pseudomonas aeruginosa (both Gram-negative), and Clostridium perfringens (Gram-positive) as acceptors. Using this pgl integrant E. coli strain, four glycoconjugates were readily generated. Two glycoconjugates, where both protein and glycan are from C. jejuni (double-hit vaccines), and two glycoconjugates, where the glycan antigen is conjugated to a detoxified toxin from a different pathogen (single-hit vaccines). Because the downstream application of Live Attenuated Vaccine Strains (LAVS) against C. jejuni is to be used in poultry, which have a higher body temperature of 42 °C, we investigated the effect of temperature on protein expression and glycosylation in the E. coli pgl integrant strain. Conclusions We determined that glycosylation is temperature dependent and that for the combination of heptasaccharide and carriers used in this study, the level of PglB available for glycosylation is a step limiting factor in the glycosylation reaction. We also demonstrated that temperature affects the ability of PglB to glycosylate its substrates in an in vitro glycosylation assay independent of its transcriptional level.

Enhancement of the Yersinia pestis EV NIIEG Vaccine Srain Immunogenic and Protective Activity under Cultivation with Azoxymer Bromide (Polyoxidonium)

Background. The live-attenuated vaccine based on the Yersinia pestis strain EV line NIIEG is still used in Russia, providing protective efficacy against plague. Nevertheless, there is an urgent need for developing new ways to increase the immunogenicity of the Y. pestis EV NIIEG vaccine strain. In this study, the ability of direct action of immunoadjuvant azoximer bromide (polyoxidonium, PO) on the immunobiological properties of vaccine strain Y. pestis EV NIIEG during cultivation on a dense nutrient medium was evaluated. Materials & Methods. Y.pestis EV NIIEG, cultivated at 28 °С for 48 h on LB agar, Miller pH 7.2 ± 0.1 (Sigma-Aldrich, USA) with the addition of PO and without. MALDI-TOF mass-spectrometry was deployed for the obtainment of mass-spectra of ribosomal proteins from Y. pestis EV NIIEG cells on the MicroflexTM LT mass spectrometer (Bruker Daltonics, Germany). Protective efficacy was evaluated under subcutaneously challenge guinea pigs and mice BALB's with 400 LD50 doses of the Y. pestis 231, Y. pestis P-13268 Vietnam (MLD=5 CFU). Antibody titers to F1 in serum were determined using an ELISA. Results. The addition of the therapeutic concentration of PO in the cultivation medium induced a significant increase in the immunogenicity of Y. pestis EV NIIEG that resulted in enhancement of serum antibody levels against Y. pestis F1 antigen and several times the growth of protective efficacy in the bubonic plague model on two types of experimental animals. ImD50 of the vaccine strain Y. pestis EV NIIEG, cultivated with PO, was significantly (p < 0,05) lower in comparison to ImD50 for Y. pestis EV NIIEG in standard cultivation conditions. One year of storage at a temperature of 4 °С did not alter the protective properties of the vaccine strain Y. pestis EV NIIEG, cultivated with PO. Conclusions. Morphological studies confirmed the absence of influence PO introduction into the cultivation environment on the safety of the vaccine strain. MALDI-TOF MS profile of the Y. pestis EV NIIEG, cultivated with PO, had peaks characteristic features. The mass peak at m/z 3,061 was significantly down-regulated and new mass peaks at m/z 2,759, m/z 3,533 were determined. These changes are accompanied by the increase of Y. pestis EV NIIEG immunogenicity.

Lifelong Cytomegalovirus and Early-Life Irradiation Synergistically Potentiate Age-Related Defects in Response to Vaccination and Infection

ABSTRACTA popular “DNA-damage theory” of aging posits that unrepaired DNA damage leads to cellular (and organismal) senescence. Indeed, some hallmarks of immune aging are more prevalent in individuals exposed to Whole-Body Irradiation (WBI). To test this hypothesis in a model relevant to human immune aging, we examined separate and joint effects of lifelong latent Murine Cytomegalovirus (MCMV) and early-life WBI (i) over the course of the lifespan; (ii) in response to a West Nile virus (WNV) live attenuated vaccine; and (iii) following lethal WNV challenge subsequent to vaccination. We recently published that a single dose of non-lethal WBI in youth, on its own, was not sufficient to accelerate aging of the murine immune system despite causing widespread DNA damage and repopulation stress in hematopoietic cells. However, 4Gy sub-lethal WBI caused manifest reactivation of MCMV. Following vaccination and challenge with WNV in the old age, MCMV-infected animals experiencing 4Gy, but not lower, dose of sub-lethal WBI in youth had reduced survival. By contrast, old irradiated mice lacking MCMV and MCMV-infected, but not irradiated, mice were both protected to the same high level as the old non-irradiated, uninfected controls. Analysis of the quality and quantity of anti-WNV immunity showed that higher mortality in MCMV-positive WBI mice correlated with increased levels of MCMV-specific immune activation during WNV challenge. Moreover, we demonstrate that infection, including that by WNV, led to MCMV reactivation. Our data suggest that MCMV reactivation may be an important determinant of increased late-life mortality following early-life irradiation and late-life acute infection.

Evaluation of Recombinant Herpesvirus of Turkey Laryngotracheitis (rHVT-LT) Vaccine against Genotype VI Canadian Wild-Type Infectious Laryngotracheitis Virus (ILTV) Infection

In Alberta, infectious laryngotracheitis virus (ILTV) infection is endemic in backyard poultry flocks; however, outbreaks are only sporadically observed in commercial flocks. In addition to ILTV vaccine revertant strains, wild-type strains are among the most common causes of infectious laryngotracheitis (ILT). Given the surge in live attenuated vaccine-related outbreaks, the goal of this study was to assess the efficacy of a recombinant herpesvirus of turkey (rHVT-LT) vaccine against a genotype VI Canadian wild-type ILTV infection. One-day-old specific pathogen-free (SPF) White Leghorn chickens were vaccinated with the rHVT-LT vaccine or mock vaccinated. At three weeks of age, half of the vaccinated and the mock-vaccinated animals were challenged. Throughout the experiment, weights were recorded, and feather tips, cloacal and oropharyngeal swabs were collected for ILTV genome quantification. Blood was collected to isolate peripheral blood mononuclear cells (PBMC) and quantify CD4+ and CD8+ T cells. At 14 dpi, the chickens were euthanized, and respiratory tissues were collected to quantify genome loads and histological examination. Results showed that the vaccine failed to decrease the clinical signs at 6 days post-infection. However, it was able to significantly reduce ILTV shedding through the oropharyngeal route. Overall, rHVT-LT produced a partial protection against genotype VI ILTV infection.

Single dose of chimeric dengue-2/Zika vaccine candidate protects mice and non-human primates against Zika virus

The development of a safe and effective Zika virus (ZIKV) vaccine has become a global health priority since the widespread epidemic in 2015-2016. Based on previous experience in using the well-characterized and clinically proven dengue virus serotype-2 (DENV-2) PDK-53 vaccine backbone for live-attenuated chimeric flavivirus vaccine development, we developed chimeric DENV-2/ZIKV vaccine candidates optimized for growth and genetic stability in Vero cells. These vaccine candidates retain all previously characterized attenuation phenotypes of the PDK-53 vaccine virus, including attenuation of neurovirulence for 1-day-old CD-1 mice, absence of virulence in interferon receptor-deficient mice, and lack of transmissibility in the main mosquito vectors. A single DENV-2/ZIKV dose provides protection against ZIKV challenge in mice and rhesus macaques. Overall, these data indicate that the ZIKV live-attenuated vaccine candidates are safe, immunogenic and effective at preventing ZIKV infection in multiple animal models, warranting continued development.

ImmunoStart: preparing patients for immunosuppression

Objectives Patients with immune-mediated inflammatory disease (IMID) present an increased risk of infection. Here, we present the concept of a preventive consultation called ImmunoStart and the first results of its implementation in the care pathway of patients with IMID. Methods Relevant information about vaccination history, TB exposition and other infectious risks are collected through blood sampling, complete anamnesis, chest X-Ray and Mantoux test. During ImmunoStart consultation, vaccination schedules, specific treatments and risk considerations are discussed. Results Between October 2016 and February 2020, 437 patients were seen at the ImmunoStart consultation, mainly referred by rheumatologists (56%), dermatologists (25%), and gastroenterologists (18%). A total of 421 (96%) patients needed at least one vaccine (a mean of 3.3 vaccines per patient). Live attenuated vaccine was indicated for 45 patients (10%), requiring them to reduce or interrupt their immunosuppressive drug(s). Ninety-two patients (21%) were treated for latent TB infection. Conclusion This preventive consultation provides a centralized and systematic setting for the direct management of patients with IMID in need of vaccination, treatment of latent disease and specific advice regarding their immunomodulating treatments.