Immune and behavioral correlates of protection against symptomatic post-vaccination SARS-CoV-2 infection.

Introduction: We sought to determine pre-infection correlates of protection against SARS-CoV-2 post-vaccine inzfections (PVI) acquired during the first Omicron wave in the United States. Methods: Serum and saliva samples from 176 vaccinated adults were collected from October to December of 2021, immediately before the Omicron wave, and assessed for SARS-CoV-2 Spike-specific IgG and IgA binding antibodies (bAb). Sera were also assessed for bAb using commercial assays, and for neutralization activity against several SARS-CoV-2 variants. PVI duration and severity, as well as risk and precautionary behaviors, were assessed by questionnaires. Results: Serum anti-Spike IgG levels assessed by research assay, neutralization titers against Omicron subvariants, and low home risk scores correlated with protection against PVIs after multivariable regression analysis. Commercial assays did not perform as well as research assay, likely due to their lower dynamic range. Discussion: In the 32 participants that developed PVI, anti-Spike IgG bAbs correlated with lower disease severity and shorter duration of illness.

Differentiation of lipoedema from bilateral lower limb lymphoedema by imaging assessment of indocyanine green lymphography.

Lipoedema is characterized by disproportionate painful fat accumulation mostly in the lower limbs. The presence of lymphoedema in lipoedema remains controversial. This study aimed to assess the presence or absence of lymphoedema in the lower limbs of women with lipoedema using indocyanine green (ICG) lymphography. A cross-sectional retrospective study was undertaken in women with a clinical diagnosis of lipoedema whose lower limbs were examined with ICG lymphography. MD Anderson Cancer Center (MDACC) ICG staging was used to determine lymphoedema presence and severity. Patient characteristics, ICG lymphography findings, Stemmer sign, body mass index, waist-to-hip ratio, limb volume and bioimpedance spectroscopy measures were recorded. Forty women with lipoedema underwent ICG lymphography for the lower limbs from January 2018 to July 2022. Thirty-four women (85.0%) were determined by ICG lymphography as MDACC ICG Stage 0 representing normal lymphatics. Of the six women who demonstrated dermal backflow on ICG lymphography, all were determined as ICG Stage 1, four had localized traumatic dermal backflow area at their ankles, one had previously diagnosed with primary lymphoedema and one was classified as lipoedema stage 4. ICG lymphography findings suggested the absence of lymphoedema in a clear majority of women with lower limb lipoedema.

Retrograde lymph flow in the lymphatic vessels in limb lymphedema.

OBJECTIVE: Retrograde movement of lymph owing to damaged and/or incompetent valves in the lymphatic vessels has been considered a pathological feature of lymphedema. This study aimed to determine the prevalence of retrograde lymph flow and the characteristics of patients with this condition using indocyanine green (ICG) lymphography. METHODS: An audit of 679 patients with upper or lower limb swelling who underwent ICG lymphography was undertaken over a 4-year period. Harvey's technique was applied to identify retrograde flow in the lymph collecting vessel during ICG lymphography. The characteristics of patients with retrograde lymph flow were recorded. RESULTS: Twenty-one patients (3.7%; lower limb, n = 19; upper limb, n = 2) were identified as having retrograde flow in lymph collecting vessels out of 566 confirmed lymphedema patients (lower limb, n = 275; upper limb, n = 291). Of the two patients with upper limb lymphedema (ULLE), one had a short segment of retrograde lymph flow in the forearm. The other patient with ULLE and one patient with lower limb lymphedema (LLLE) were previously diagnosed with lymphedema-distichiasis syndrome. Of the remaining 18 patients with LLLE and retrograde lymph flow, nine had initiating insect bites with lymphangitis and three had palpable benign enlarged inguinal lymph nodes evident before lower limb swelling onset. None had cancer-related LLLE. CONCLUSIONS: Retrograde lymph flow with valve incompetence in the lymph-collecting vessels was a rare finding in ULLE and a relatively uncommon finding in LLLE, contradicting the conventional understanding of pathological changes in lymphedema. ICG lymphography identified anticipated retrograde lymph flow in two patients with lymphedema distichiasis. In the remaining patients, retrograde lymph flow may have resulted from toxic or asymptomatic lymphangitis but there was no association with secondary cancer-related lymphedema. These findings have implication for conservative management as well as lymphovenous anastomosis surgery where both ends of a transected lymph collecting vessel would be potential targets for anastomoses.

Durability of Antibody Response and Frequency of SARS-CoV-2 Infection 6 Months after COVID-19 Vaccination in Healthcare Workers.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies decay but persist 6 months postvaccination; lower levels of neutralizing titers persist against Delta than wild-type virus. Of 227 vaccinated healthcare workers tested, only 2 experienced outpatient symptomatic breakthrough infections, despite 59/227 exhibiting serologic evidence of SARS-CoV-2 infection, defined as presence of nucleocapsid protein antibodies.

Prospective Assessment of Symptoms to Evaluate Asymptomatic SARS-CoV-2 Infections in a Cohort of Health Care Workers.

BACKGROUND: The frequency of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is unclear and may be influenced by how symptoms are evaluated. In this study, we sought to determine the frequency of asymptomatic SARS-CoV-2 infections in a prospective cohort of health care workers (HCWs). METHODS: A prospective cohort of HCWs, confirmed negative for SARS-CoV-2 exposure upon enrollment, were evaluated for SARS-CoV-2 infection by monthly analysis of SARS-CoV-2 antibodies as well as referral for polymerase chain reaction testing whenever they exhibited symptoms of coronavirus disease 2019 (COVID-19). Participants completed the standardized and validated FLU-PRO Plus symptom questionnaire scoring viral respiratory disease symptom intensity and frequency at least twice monthly during baseline periods of health and each day they had any symptoms that were different from their baseline. RESULTS: Two hundred sixty-three participants were enrolled between August 25 and December 31, 2020. Through February 28, 2021, 12 participants were diagnosed with SARS-CoV-2 infection. Symptom analysis demonstrated that all 12 had at least mild symptoms of COVID-19, compared with baseline health, near or at time of infection. CONCLUSIONS: These results suggest that asymptomatic SARS-CoV-2 infection in unvaccinated, immunocompetent adults is less common than previously reported. While infectious inoculum doses and patient factors may have played a role in the clinical manifestations of SARS-CoV-2 infections in this cohort, we suspect that the high rate of symptomatic disease was due primarily to participant attentiveness to symptoms and collection of symptoms in a standardized, prospective fashion. These results have implications for studies that estimate SARS-CoV-2 infection prevalence and for public health measures to control the spread of this virus.

Adverse Effects and Antibody Titers in Response to the BNT162b2 mRNA COVID-19 Vaccine in a Prospective Study of Healthcare Workers.

BACKGROUND: The relationship between postvaccination symptoms and strength of antibody responses is unclear. The goal of this study was to determine whether adverse effects caused by vaccination with the Pfizer/BioNTech BNT162b2 vaccine are associated with the magnitude of vaccine-induced antibody levels. METHODS: We conducted a single-center, observational cohort study consisting of generally healthy adult participants that were not severely immunocompromised, had no history of coronavirus disease 2019, and were seronegative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein before vaccination. Severity of vaccine-associated symptoms was obtained through participant-completed questionnaires. Testing for immunoglobulin G antibodies against SARS-CoV-2 spike protein and receptor-binding domain was conducted using microsphere-based multiplex immunoassays performed on serum samples collected at monthly visits. Neutralizing antibody titers were determined by microneutralization assays. RESULTS: Two hundred six participants were evaluated (69.4% female, median age 41.5 years old). We found no correlation between vaccine-associated symptom severity scores and vaccine-induced antibody titers 1 month after vaccination. We also observed that (1) postvaccination symptoms were inversely correlated with age and weight and more common in women, (2) systemic symptoms were more frequent after the second vaccination, (3) high symptom scores after first vaccination were predictive of high symptom scores after second vaccination, and (4) older age was associated with lower titers. CONCLUSIONS: Lack of postvaccination symptoms after receipt of the BNT162b2 vaccine does not equate to lack of vaccine-induced antibodies 1 month after vaccination.

The Effect of the Menstrual Cycle and Oral Contraceptive Cycle on Muscle Performance and Perceptual Measures.

Most reproductive-aged women are exposed to fluctuating female steroid hormones due to the menstrual cycle or oral contraceptive use. This study investigated the potential effect of the menstrual cycle and combined monophasic oral contraceptive cycle on various aspects of muscle performance. Thirty active females (12 with a natural menstrual cycle, 10 taking a high-androgenicity oral contraceptive and 8 taking a low-androgenicity oral contraceptive), aged 18 to 30 years, were tested three times throughout one menstrual or oral contraceptive cycle. Counter-movement jumps, bilateral hop jumps, handgrip strength, isometric knee extensor strength and isokinetic knee flexion and extension were assessed. Perceptual ratings of fatigue, muscle soreness, pain and mood were recorded. Most variables showed no significant changes over the menstrual or oral contraceptive cycle. However, for the menstrual cycle group, isokinetic knee flexion at 240° s-1, and time of flight in bilateral hopping and counter movement jumps showed better results during the mid-luteal phase compared with the late follicular phase. For the high-androgenicity oral contraceptive group, isokinetic knee flexion at 240° s-1 was significantly higher in the late hormone phase compared with the early hormone phase. For the low-androgenicity oral contraceptive group, time of flight for the counter-movement jumps was lower in the late hormone phase compared with the early hormone phase. The findings indicate that faster and explosive aspects of muscle performance may be influenced by endogenous and exogenous female hormones.

The acute effect of the menstrual cycle and oral contraceptive cycle on measures of body composition.

PURPOSE: This study aimed to investigate the effect of fluctuating female hormones during the menstrual cycle (MC) and oral contraceptive (OC) cycle on different measures of body composition. METHODS: Twenty-two women with a natural MC and thirty women currently taking combined monophasic OC were assessed over three phases of the menstrual or oral contraceptive cycle. Body weight, skinfolds, bioelectric impedance analysis (BIA), ultrasound, dual-energy X-ray absorptiometry (DXA), and peripheral quantitative computed tomography (pQCT) measurements were performed to assess body composition. Urine specific gravity (USG) was measured as an indication of hydration, and serum oestradiol and progesterone were measured to confirm cycle phases. RESULTS: Five participants with a natural MC were excluded based on the hormone analysis. For the remaining participants, no significant changes over the MC and OC cycle were found for body weight, USG, skinfolds, BIA, ultrasound and pQCT measures. However, DXA body fat percentage and fat mass were lower in the late follicular phase compared to the mid-luteal phase of the MC, while for the OC cycle, DXA body fat percentage was higher and lean mass lower in the early hormone phase compared with the late hormone phase. CONCLUSION: Our findings suggest that assessment of body fat percentage through BIA and skinfolds may be performed without considering the MC or OC cycle. Body adiposity assessment via DXA, however, may be affected by female hormone fluctuations and therefore, it may be advisable to perform repeat testing using DXA during the same phase of the MC or OC cycle.

Adverse effects and antibody titers in response to the BNT162b2 mRNA COVID-19 vaccine in a prospective study of healthcare workers.

BACKGROUND: mRNA COVID-19 vaccines are playing a key role in controlling the COVID-19 pandemic. The relationship between post-vaccination symptoms and strength of antibody responses is unclear. OBJECTIVE: To determine whether adverse effects caused by vaccination with the Pfizer/BioNTech BNT162b2 vaccine are associated with the magnitude of vaccine-induced antibody levels. DESIGN: Single center, prospective, observational cohort study. SETTING: Participants worked at Walter Reed National Military Medical Center and were seen monthly at the Naval Medical Research Center Clinical Trials Center. PARTICIPANTS: Generally healthy adults that were not severely immunocompromised, had no history of COVID-19, and were seronegative for SARS-CoV-2 spike protein prior to vaccination. MEASURES: Severity of vaccine-associated symptoms was obtained through participant completed questionnaires. Testing for IgG antibodies against SARS-CoV-2 spike protein and receptor binding domain was conducted using microsphere-based multiplex immunoassays. RESULTS: 206 participants were evaluated (69.4% female, median age 41.5 years old). We found no correlation between vaccine-associated symptom severity scores and vaccine-induced antibody titers one month after vaccination. We also observed that 1) post-vaccination symptoms were inversely correlated with age and weight and more common in women, 2) systemic symptoms were more frequent after the second vaccination, 3) high symptom scores after first vaccination were predictive of high symptom scores after second vaccination, and 4) older age was associated with lower titers. LIMITATIONS: Study only observes antibody responses and consists of healthy participants. CONCLUSIONS: Lack of post-vaccination symptoms following receipt of the BNT162b2 vaccine does not equate to lack of vaccine-induced antibodies one month after vaccination. This study also suggests that it may be possible to design future mRNA vaccines that confer robust antibody responses with lower frequencies of vaccine-associated symptoms. FUNDING: This study was executed by the Infectious Disease Clinical Research Program (IDCRP), a Department of Defense (DoD) program executed by the Uniformed Services University of the Health Sciences (USUHS) through a cooperative agreement by the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF). This project has been funded by the Defense Health Program, U.S. DoD, under award HU00012120067. Project funding for JHP was in whole or in part with federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. HHSN261200800001E. The funding bodies have had no role in the study design or the decision to submit the manuscript for publication.

Prospective Assessment of SARS-CoV-2 Seroconversion (PASS) study: an observational cohort study of SARS-CoV-2 infection and vaccination in healthcare workers.

BACKGROUND: SARS-CoV-2 is a recently emerged pandemic coronavirus (CoV) capable of causing severe respiratory illness. However, a significant number of infected people present as asymptomatic or pauci-symptomatic. In this prospective assessment of at-risk healthcare workers (HCWs) we seek to determine whether pre-existing antibody or T cell responses to previous seasonal human coronavirus (HCoV) infections affect immunological or clinical responses to SARS-CoV-2 infection or vaccination. METHODS: A cohort of 300 healthcare workers, confirmed negative for SARS-CoV-2 exposure upon study entry, will be followed for up to 1 year with monthly serology analysis of IgM and IgG antibodies against the spike proteins of SARS-CoV-2 and the four major seasonal human coronavirus - HCoV-OC43, HCoV-HKU1, HCoV-229E, and HCoV-NL63. Participants will complete monthly questionnaires that ask about Coronavirus Disease 2019 (COVID-19) exposure risks, and a standardized, validated symptom questionnaire (scoring viral respiratory disease symptoms, intensity and severity) at least twice monthly and any day when any symptoms manifest. SARS-CoV-2 PCR testing will be performed any time participants develop symptoms consistent with COVID-19. For those individuals that seroconvert and/or test positive by SARS-CoV-2 PCR, or receive the SARS-CoV-2 vaccine, additional studies of T cell activation and cytokine production in response to SARS-CoV-2 peptide pools and analysis of Natural Killer cell numbers and function will be conducted on that participant's cryopreserved baseline peripheral blood mononuclear cells (PBMCs). Following the first year of this study we will further analyze those participants having tested positive for COVID-19, and/or having received an authorized/licensed SARS-CoV-2 vaccine, quarterly (year 2) and semi-annually (years 3 and 4) to investigate immune response longevity. DISCUSSION: This study will determine the frequency of asymptomatic and pauci-symptomatic SARS-CoV-2 infection in a cohort of at-risk healthcare workers. Baseline and longitudinal assays will determine the frequency and magnitude of anti-spike glycoprotein antibodies to the seasonal HCoV-OC43, HCoV-HKU1, HCoV-229E, and HCoV-NL63, and may inform whether pre-existing antibodies to these human coronaviruses are associated with altered COVID-19 disease course. Finally, this study will evaluate whether pre-existing immune responses to seasonal HCoVs affect the magnitude and duration of antibody and T cell responses to SARS-CoV-2 vaccination, adjusting for demographic covariates.

Personalizing Conservative Lymphedema Management Using Indocyanine Green-Guided Manual Lymphatic Drainage.

Background: The Australian Lymphoedema Education, Research and Treatment Program (ALERT) at Macquarie University in Sydney, Australia is one of the flagship programs of Australia's first fully integrated academic health sciences centre, MQ Health. The aim of this study was to describe our findings of compensatory drainage demonstrated by indocyanine green (ICG) lymphography in cancer-related upper and lower limb lymphedema and how this may be translated into clinical practice. Methods and Results: Retrospective data from 339 patients aged between 18 and 90 years with secondary cancer-related unilateral or bilateral lymphedema of the upper or lower limb who underwent ICG lymphography assessment at the ALERT clinic between February 2017 and March 2020 were analyzed. In patients with upper limb lymphedema, the ipsilateral axilla was the most frequent drainage region (74.9%), followed by clavicular (41.8%) and parasternal (11.3%). For patients with mild upper limb lymphedema, 94.4% drained to the ipsilateral axilla. No patients drained to the ipsilateral inguinal region. For lower limb lymphedema, drainage to the ipsilateral inguinal was most common (52.3%), followed by contralateral inguinal (30.7%), popliteal (26.1%), and gluteal (21.6%) regions. Three main patterns of superficial lymphatic compensation were identified based on which anatomical structure carried lymph fluid. Manual lymphatic drainage (MLD) was used to facilitate movement of the dye. A light/effleurage technique was sufficient to move the dye through patent lymphatic vessels; a slow and firmer technique was required to move the dye through areas of bridging dermal backflow. Conclusion: The introduction of ICG lymphography to our program and its use in guiding personalized conservative management plans, including facilitative MLD techniques, has translated into clinical practice and changed research and educational priorities within the ALERT program.

Axenic Caenorhabditis elegans antigen protects against development of type-1 diabetes in NOD mice.

Studies in humans and animals have demonstrated that infection with helminths (parasitic worms) is protective against a range of hyperinflammatory diseases. A number of factors limit translation into clinical use, including: potential contamination of helminths obtained from infected humans or animals, lack of batch to batch stability, and potential pathological risks derived from live worm infections. To overcome these limitations we tested whether an antigen homogenate of the non-pathogenic nematode Caenorhabditis elegans confers protection against type 1 diabetes mellitus (T1D) using the Non Obese Diabetic (NOD) mouse model. Our study demonstrates that twice weekly intraperitoneal injections of axenically cultured C. elegans antigen (aCeAg) confers substantial protection against type 1 diabetes in NOD mice. Whereas 80% of control mice (PBS-injected) developed clinical disease, only 10% of aCeAg-treated mice became diabetic. Additionally, aCeAg treated mice had significantly greater numbers of insulin-producing pancreatic islets and greater numbers of islets negative for lymphocyte infiltration. Immunological changes observed in aCeAg treated mice included increases in total IgE and total IgG1, consistent with induction of a type 2 immune response similar to that typically seen in parasitic worm infection. Although evidence suggests that helminth infections induce strong immunoregulatory signals, we did not observe significant changes in regulatory T cell numbers or in production of the regulatory cytokines TGFß and IL-10. The lack of a regulatory response may be due to our time point of observation, or perhaps the mechanism of aCeAg efficacy may differ from that of helminth infection. Discovery that antigens obtained from a non-parasitic environmental nematode replicate the protective phenotype induced by parasitic worm infections may accelerate our ability to develop nematode-derived therapies for allergy and autoimmune diseases.

Brugia malayi infection in ferrets - A small mammal model of lymphatic filariasis.

BACKGROUND: The lack of effective short-course therapies for treatment of the adult stage of filarial worms is a major limitation in the global effort to eliminate lymphatic filariasis. Studies using current small mammal models of lymphatic filariasis are limited by difficulties in quantifying adult worm numbers and in assessing lymphatic anatomy and function. METHODOLOGY/PRINCIPAL FINDINGS: Here, we re-established Brugia malayi infection of ferrets as a model for lymphatic filariasis and demonstrated parasitological, immunological, and histological parallels with human infection. Subcutaneous injection of L3 larvae into a hind-footpad resulted in a mean of 18 adult worms recovered 16 weeks post-infection, primarily from the draining inguinal and femoral lymphatics of the injected limb. Infected ferrets developed microfilaremia, with patency lasting from 12-26 weeks post-infection. Quantitative PCR assessing cytokine transcription by antigen-stimulated lymph node cells demonstrated a mixed Th1/Th2 response occurring during early infection. Immunoregulation with production of down-regulatory cytokine IL-10 occurred just prior to peak microfilaremia. Histological analysis revealed progressive inflammation of the lymphatic vessel walls, with intimal thickening and disorganization of collagen fibers. Inflammation was observed as early as 8 weeks post-infection and extended into the perivascular and subcutaneous tissues by 16 weeks post-infection. Finally, we developed a novel ferret PET/CT lymphoscintigraphy method demonstrating substantial changes in lymphatic anatomy and function as early as 3 weeks post-infection, with progression over the course of infection. CONCLUSIONS/SIGNIFICANCE: B. malayi infection of ferrets is a robust model of human lymphatic filariasis that can be utilized to study efficacy of novel antifilarial agents against adult worms residing within lymphatic vessels. In conjunction with PET/CT lymphoscintigraphy, this model can also be used to investigate pathogenesis of lymphatic dysfunction in lymphatic filariasis and efficacy of medications aimed at reversing lymphatic dysfunction after clearance of adult worms.