A null mutation was prepared in the mouse for CD18, the β2 subunit of leukocyte integrins. Homozygous CD18 null mice develop chronic dermatitis with extensive facial and submandibular erosions. The phenotype includes elevated neutrophil counts, increased immunoglobulin levels, lymphadenopathy, splenomegaly, and abundant plasma cells in skin, lymph nodes, gut, and kidney. Very few neutrophils were found in spontaneously occurring skin lesions or with an induced toxic dermatitis. Intravital microscopy in CD18 null mice revealed a lack of firm neutrophil attachment to venules in the cremaster muscle in response to N-formyl- methionyl-leucyl-phenylalanine. A severe defect in T cell proliferation was found in the CD18 null mice when T cell receptors were stimulated either by staphylococcal enterotoxin A or by major histocompatibility complex alloantigens demonstrating a greater role of CD11/CD18 integrins in T cell responses than previously documented. The null mice are useful for delineating the functions of CD18 in vivo.

Summary of study A multi-country randomized, placebo-controlled trial of the safety, immunogenicity and efficacy of respiratory syncytial virus (RSV) F-protein nanoparticle vaccine was undertaken in 4,636 pregnant women and their infants. RSV F-protein vaccine was safe and immunogenic in the pregnant women inducing anti-F IgG, palivizumab-competing antibodies and RSV neutralizing antibodies that were transferred to the fetus. Although the primary endpoint of prevention of RSV-specific medically-significant lower respiratory tract infection (MS-LRTI) was not met per protocol criteria for efficacy (i.e. 97.52% lower bound >30%), vaccine efficacy was 39.4% (97.52% CI: -1.0, 63.7%; p=0.0278) in infants 0-90 days age. Furthermore, there was a 58.8% (95% CI 31.9, 75.0%) lower rate of RSV LRTI with severe hypoxemia (secondary endpoint) through to 90 days of age in the expanded intent-to-treat analysis. The number of women needed to be vaccinated to prevent RSV-specific MS-LRTI or LRTI with severe hypoxemia in their infants through to 180 days of life were 88 and 82, respectively. Background RSV is the dominant cause of severe lower respiratory tract infection (LRTI) in infants, with most severe disease concentrated in younger-age infants. Methods Healthy, pregnant women between 28 and 36 weeks gestation, with expected delivery near the start of the RSV season, were randomized to a single intramuscular dose of nanoparticle RSV F-protein vaccine, or placebo in a 2:1 ratio. Their infants were followed for 180 days for medically-significant LRTI (MS-LRTI), LRTI with severe hypoxemia and/or LRTI- hospitalization. RSV detection was performed centrally by PCR. Safety evaluation continued until 364 days age. Results 4,636 women were randomized, with 4,579 live births. Over the first 90 days of life, efficacy against RSV-MS-LRTI was 39.4% (97.52%CI: -1.0, 63.7%; p=0.0278) and 41.4% (95%CI: 5.3, 61.2%) in the per protocol and expanded intent-to-treat (eITT) analyses, respectively. There was a lower rate (efficacy 58.8%; 95%CI 31.9, 75.0% in eITT analysis; not adjusted for multiplicity) of RSV-LRTI with severe hypoxemia in infants of vaccinees through 90 days age. Pneumonia reported as a serious adverse events was 49.4% less common in infants of vaccinees (2.6%) than placebo-recipients through 364 days age. Conclusions Maternal vaccination with RSV F-nanoparticle vaccine was safe and immunogenic. The prespecified primary endpoint success criterion (efficacy 97.5% lower bound ≥30%) was not achieved. However, maternal immunization was associated with reduced risk of RSV-confirmed MS-LRTI and LRTI with severe hypoxemia in early infancy. Trial Registration Number ClinicalTrials.Gov: NCT02624947. Funding statement Funded by Novavax, with supporting grant from the Bill and Melinda Gates Foundation.

This is a Brighton Collaboration Case Definition of the term “Multisystem Inflammatory Syndrome in Children and Adults (MIS-C/A)” to be utilized in the evaluation of adverse events following immunization. The case definition was developed by topic experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2. The format of the Brighton Collaboration was followed, including an exhaustive review of the literature, to develop a consensus definition and defined levels of certainty. The document underwent peer review by the Brighton Collaboration Network and by selected expert external reviewers prior to submission. The comments of the reviewers were taken into consideration and edits incorporated into this final manuscript.

Preterm birth is commonly defined as any birth before 37 weeks completed weeks of gestation. An estimated 15 million infants are born preterm globally, disproportionately affecting low and middle income countries (LMIC). It contributes directly to estimated one million neonatal deaths annually and is a significant contributor to childhood morbidity. However, in many clinical settings, the information available to calculate completed weeks of gestation varies widely. Accurate dating of the last menstrual period (LMP), as well as access to clinical and ultrasonographic evaluation are important components of gestational age assessment antenatally. This case definition assign levels of confidence to categorisation of births as preterm, utilising assessment modalities which may be available across different settings. These are designed to enable systematic safety evaluation of vaccine clinical trials and post-implementation programmes of immunisations in pregnancy.

A retrospective review of adenovirus infections at Texas Children's Hospital during 1990-1996 was performed to evaluate the epidemiology, clinical course, management, and outcome of disseminated adenovirus disease (DAD) in children. DAD with multiorgan involvement occurred in 11 (2.5%) of 440 adenovirus-infected patients. Six (54%) of the 11 were immunocompromised and 5 (45%) were immunocompetent. Mortality was 83% among the immunodeficient, 60% in the immunocompetent, and 73% overall. Two (28%) of the 7 patients receiving immunoglobulins with or without antivirals and 3 (75%) of the 4 not treated died of DAD. DAD was caused by particular serotypes (3, 5, and 7) and occurred at a younger age in immunocompetent children. Viremia and prolonged viral excretion were more common in the immunocompromised. Clinical features and outcome were similar in both groups. Prospective studies addressing the use of new antiviral agents, combination antiviral therapy, and preventive strategies are necessary to determine the optimal therapeutic approach for patients with DAD.

Background Cytomegalovirus (CMV) is a leading cause of congenital infection and an important target for vaccine development. Methods CMV seronegative girls between 12 and 17 years of age received CMV glycoprotein B (gB) vaccine with MF59 or saline placebo at 0, 1 and 6 months. Blood and urine were collected throughout the study for evidence of CMV infection based on PCR and/or seroconversion to non-vaccine CMV antigens. Results 402 CMV seronegative subjects were vaccinated (195 vaccine, 207 placebo). The vaccine was generally well tolerated, although local and systemic adverse events were significantly more common in the vaccine group. The vaccine induced gB antibody in all vaccine recipients with a gB geometric mean titer of 13,400 EU; 95%CI 11,436, 15,700, after 3 doses. Overall, 48 CMV infections were detected (21 vaccine, 27 placebo). In the per protocol population (124 vaccine, 125 placebo) vaccine efficacy was 43%; 95% CI: −36; 76, P=0.20. The most significant difference was after 2 doses, administered as per protocol; vaccine efficacy 45%, 95% CI: −9; 72, P=0.08. Conclusion The vaccine was safe and immunogenic. Although the efficacy did not reach conventional levels of significance, the results are consistent with a previous study in adult women (Pass et al NEJM 360:1191, 2009) using the same formulation.

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Background Intrauterine herpes simplex virus (HSV) infection often is omitted from descriptions of neonatal HSV disease. Previous characterizations of intrauterine HSV infection limit manifestations to the triad of cutaneous, central nervous system (CNS), and ophthalmologic findings. We report 3 cases of intrauterine HSV infection and provide a contemporary literature review of this disease. Methods Cases published between 1963 and January 2009 were identified. Selected cases fit the clinical description of intrauterine HSV infection, had manifestations present at birth, and had virologic confirmation of infection. Results This review yielded 64 cases, 3 of which were our own, of intrauterine HSV infection. Less than one-third fit the typical triad. Of the patients with cutaneous findings at birth, 24 (44%) had manifestations other than vesicles or bullae. Confirmation of HSV infection by culture of cutaneous lesions present at birth was delayed beyond 72 hours after birth in 15 patients and occurred at a median of 10 days of age. Nine of these patients had lesions at birth that were neither vesicles nor bullae, and 14 cases were confirmed by culture of new vesicles. Conclusions More than two-thirds of reported cases do not present with the typical triad. Cutaneous findings are not limited to vesicles or bullae. A high index of suspicion and recognition of varied cutaneous manifestations is necessary to diagnose infants with intrauterine HSV infection.