The Neurophysiological Lesion: A Scoping Review.

Objective: The purpose of this study was to examine the extent of the literature on the neurophysiological lesion as referenced in functional neurology. Methods: A literature search was performed within the period from 2010 to March 2021. Search terms included central sensitization, central sensitivity syndrome, nociplastic pain, cold hyperalgesia, heat hyperalgesia, mechanical hyperalgesia, dynamic mechanical allodynia, temporal summation, spatial summation, and descending inhibition. A qualitative synthesis summarized the research findings, including clinical conditions and effect of spinal manipulation. Results: There were 30 studies, which included 7 high-level studies (meta-analysis or systematic reviews), 22 randomized controlled studies, and 1 scoping review. The findings suggest the existence of the changes in the central integrated state of a population of neurons with various disorders, experimentally induced stimulation, and treatment. The current literature suggests plasticity of the central integrative state (CIS) with the onset of pathologies and the changes in the CIS with different conservative nonpharmacologic treatments. Conclusions: This review suggests changes in the resting state of the CIS of a population of neurons that exist in the physiologic lesion may change in response to various therapies, including manipulative therapy. The findings from this review provide support of the hypothesis that nonpharmacologic conservative care may affect the neurophysiological lesion. However, studies were heterogeneous and evidence was lacking in the translation of targeting the therapies to distinct neuronal areas for clinical outcomes to treat specific disease states.

An investigation into chiropractic intern adherence to radiographic guidelines in clinical decisions with a descriptive comparison to clinical practitioners.

OBJECTIVE: The purpose of this study was to assess chiropractic interns' knowledge and adherence to radiographic clinical practice guidelines (CPGs) and compare their clinical decisions to previous surveys of established practitioners in Canada and Australia. METHODS: A clinical decision-making survey was administered to 88 interns. The survey contained clinical scenarios and vignettes with inquiries regarding indications for radiographic referral, the likelihood of referral, and the application of CPGs. RESULTS: Forty-four percent (43.75%) of the interns were aware of CPGs, 38.75% were unsure, and 17.5% were not aware. When asked specific questions about the appropriateness of diagnostic imaging, the interns' responses were similar to those of practitioners in Canada and Australia. When interns evaluated a clinical vignette, there was lower compliance with CPGs. CONCLUSION: The interns' clinical decisions regarding the use of diagnostic radiography did not significantly differ from those of practitioners who were surveyed in other related studies. Interns were inconsistent in applying their decision making in clinical cases. Notwithstanding the similarities with practitioners, some deviation from the guidelines indicates the need for further intern education to improve the implementation of CPGs for optimal cost-effective and clinically appropriate care.

The Rise and Fall of SARS-CoV-2 Variants and Ongoing Diversification of Omicron.

In late December of 2019, high-throughput sequencing technologies enabled rapid identification of SARS-CoV-2 as the etiological agent of COVID-19, and global sequencing efforts are now a critical tool for monitoring the ongoing spread and evolution of this virus. Here, we provide a short retrospective analysis of SARS-CoV-2 variants by analyzing a subset (n = 97,437) of all publicly available SARS-CoV-2 genomes (n = ~11.9 million) that were randomly selected but equally distributed over the course of the pandemic. We plot the appearance of new variants of concern (VOCs) over time and show that the mutation rates in Omicron (BA.1) and Omicron sub-lineages (BA.2-BA.5) are significantly elevated compared to previously identified SARS-CoV-2 variants. Mutations in Omicron are primarily restricted to the spike and nucleocapsid proteins, while 24 other viral proteins-including those involved in SARS-CoV-2 replication-are generally conserved. Collectively, this suggests that the genetic distinction of Omicron primarily arose from selective pressures on the spike, and that the fidelity of replication of this variant has not been altered.

Best Practices for Chiropractic Management of Adult Patients With Mechanical Low Back Pain: A Clinical Practice Guideline for Chiropractors in the United States.

OBJECTIVE: The purpose of this paper was to update the previously published 2016 best-practice recommendations for chiropractic management of adults with mechanical low back pain (LBP) in the United States. METHODS: Two experienced health librarians conducted the literature searches for clinical practice guidelines and other relevant literature, and the investigators performed quality assessment of included studies. PubMed was searched from March 2015 to September 2021. A steering committee of 10 experts in chiropractic research, education, and practice used the most current relevant guidelines and publications to update care recommendations. A panel of 69 experts used a modified Delphi process to rate the recommendations. RESULTS: The literature search yielded 14 clinical practice guidelines, 10 systematic reviews, and 5 randomized controlled trials (all high quality). Sixty-nine members of the panel rated 38 recommendations. All but 1 statement achieved consensus in the first round, and the final statement reached consensus in the second round. Recommendations covered the clinical encounter from history, physical examination, and diagnostic considerations through informed consent, co-management, and treatment considerations for patients with mechanical LBP. CONCLUSION: This paper updates a previously published best-practice document for chiropractic management of adults with mechanical LBP.

The Role of Chiropractic Care in Providing Health Promotion and Clinical Preventive Services for Adult Patients with Musculoskeletal Pain: A Clinical Practice Guideline.

Objective: To develop evidence-based recommendations on best practices for delivery of clinical preventive services by chiropractors and to offer practical resources to empower provider applications in practice. Design: Clinical practice guideline based on evidence-based recommendations of a panel of practitioners and experts on clinical preventive services. Methods: Synthesizing the results of a literature search for relevant clinical practice guidelines and systematic reviews, a multidisciplinary steering committee with training and experience in health promotion, clinical prevention, and/or evidence-based chiropractic practice drafted a set of recommendations. A Delphi panel of experienced practitioners and faculty, primarily but not exclusively chiropractors, rated the recommendations by using the formal consensus methodology established by the RAND Corporation/University of California. Results: The Delphi consensus process was conducted during January-February 2021. The 65-member Delphi panel reached a high level of consensus on appropriate application of clinical preventive services for screening and health promotion counseling within the chiropractic scope of practice. Interprofessional collaboration for the successful delivery of clinical preventive services was emphasized. Recommendations were made on primary, secondary, tertiary, and quaternary prevention of musculoskeletal pain. Conclusions: Application of this guideline in chiropractic practice may facilitate consistent and appropriate use of screening and preventive services and foster interprofessional collaboration to promote clinical preventive services and contribute to improved public health.

Low-Level Laser Light Therapy Dosage Variables vs Treatment Efficacy of Neuromusculoskeletal Conditions: A Scoping Review.

OBJECTIVE: The purpose of this scoping review was to identify and synthesize literature on dosage variables on the efficacy of low-level laser therapy (LLLT) for neuromusculoskeletal conditions. METHODS: A scoping literature review was conducted by searching the following databases: the Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature, Medline, the Physiotherapy Evidence Database, the Index to Chiropractic Literature, manufacturer websites, and online guidelines. The search was modeled after STARLITE criteria. The reporting used Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews (PRISMA-ScR). Articles were included if LLLT was used in any treatment group for a neuromusculoskeletal complaint with dosage and effectiveness reported. This was tabulated by source, dosage variables, conditions, outcome measures, and conclusions. Data were charted in Excel format. Frequency counts were performed on ordinal data. Descriptive statistics were computed for the continuous data. RESULTS: A total of 86 articles were included in the review. They revealed a broad range of musculoskeletal conditions and diverse dosage parameters. Seven individual parameters were found that would alter the dosage. Although duration of application is an independent clinical factor, the negative-outcome studies were inconsistent in duration. There was lack of statistical difference between the studies with improved vs unimproved outcomes. No statistical differences were noted between the dosage parameters and efficacy. CONCLUSION: Although many articles were found on LLLT for neuromusculoskeletal conditions, the studies had amorphous parameters. A heterogeneity of reported doses precluded the synthesis of sufficient evidence to correlate dosage variables with improved or unimproved outcomes. Therefore, based on the current literature, dosage variables for the efficacy of LLLT for neuromusculoskeletal conditions are uncertain at this time.

Best Practices for Chiropractic Management of Patients with Chronic Musculoskeletal Pain: A Clinical Practice Guideline.

Objective: To develop an evidence-based clinical practice guideline (CPG) through a broad-based consensus process on best practices for chiropractic management of patients with chronic musculoskeletal (MSK) pain. Design: CPG based on evidence-based recommendations of a panel of experts in chronic MSK pain management. Methods: Using systematic reviews identified in an initial literature search, a steering committee of experts in research and management of patients with chronic MSK pain drafted a set of recommendations. Additional supportive literature was identified to supplement gaps in the evidence base. A multidisciplinary panel of experienced practitioners and educators rated the recommendations through a formal Delphi consensus process using the RAND Corporation/University of California, Los Angeles, methodology. Results: The Delphi process was conducted January-February 2020. The 62-member Delphi panel reached consensus on chiropractic management of five common chronic MSK pain conditions: low-back pain (LBP), neck pain, tension headache, osteoarthritis (knee and hip), and fibromyalgia. Recommendations were made for nonpharmacological treatments, including acupuncture, spinal manipulation/mobilization, and other manual therapy; modalities such as low-level laser and interferential current; exercise, including yoga; mind-body interventions, including mindfulness meditation and cognitive behavior therapy; and lifestyle modifications such as diet and tobacco cessation. Recommendations covered many aspects of the clinical encounter, from informed consent through diagnosis, assessment, treatment planning and implementation, and concurrent management and referral. Appropriate referral and comanagement were emphasized. Conclusions: These evidence-based recommendations for a variety of conservative treatment approaches to the management of common chronic MSK pain conditions may advance consistency of care, foster collaboration between provider groups, and thereby improve patient outcomes.

Production and Clinical Evaluation of Norwalk GI.1 Virus Lot 001-09NV in Norovirus Vaccine Development.

BACKGROUND: Human noroviruses (HuNoV) are the leading cause of gastroenteritis. No vaccine is currently available to prevent norovirus illness or infection. Safe, infectious challenge strains are needed to assess vaccine efficacy in the controlled human infection model (CHIM). METHODS: A stock of HuNoV strain Norwalk virus ([NV] GI.1) was prepared. Healthy, genetically susceptible adults were inoculated with NV Lot 001-09NV and monitored for infection, gastroenteritis symptoms, and immune responses. RESULTS: Lot 001-09NV induced gastroenteritis in 9 (56%) and infection in 11 (69%) of 16 genetically susceptible subjects. All infected subjects developed strong immune responses to GI.1 with a 30-fold (geometric mean titer) increase in blocking titers (BT50) and a 161-fold increase in GI.1-specific immunoglobulin (Ig)G titers when compared with baseline. GI.1-specific cellular responses in peripheral blood were observed 9 days postchallenge with an average of 3253 IgA and 1227 IgG antibody-secreting cells per million peripheral blood mononuclear cells. CONCLUSIONS: GI.1 Lot 001-09NV appears to be similar in virulence to previous passages of NV strain 8fIIa. The safety profile, attack rate, and duration of illness make GI.1 Lot 001-09NV a useful challenge strain for future vaccine studies aimed at establishing immune correlates.

Survey of chiropractic clinicians on self-reported knowledge and recognition of concussion injuries.

Background: There has been little study of the recognition of mild traumatic brain injury (MTBI) by the chiropractic practitioner, or of the inquiry by the clinician to assess those patients who may be suffering from the condition, but fail to report the symptoms. Although severe cases of TBI are more often recognized and treated by attendance to hospital or emergency room, MTBI is less recognizable and would present a long-term risk to the patient. Given the clinical risk associated with failure to recognize such injuries, training of the clinician in the subtle signs of MTBI is imperative. What we currently know about training in the recognition of MTBI is from limited recent knowledge based studies. This study is intended to assess the self-reported mild traumatic brain injury (MTBI) knowledge, recognition and treatment by chiropractic practitioners. Methods: A previously published standardized set of survey items was distributed to a captive audience of chiropractic practitioners at the July 2016 Texas Chiropractic College annual symposium. The sample population was a convenience sample of chiropractic clinicians who were assessed for MTBI knowledge and common practices. Results: There was a response rate of 43% of the 125 attendees. The survey demonstrated confidence in MTBI diagnosis. Average MTBI knowledge and recognition score was only 27% ± 22%. Frequency of MTBI patients presenting to the chiropractic clinician office was an average of less than one per month. Sixty nine percent (69%) of the clinicians relied upon their history and clinical exam for diagnosis. There was no knowledge of the Balance Error Scoring system and only 20% utilized the Standardized Concussion Assessment Tool (SCAT). The primary action of the chiropractic clinician who suspected MTBI was to refer to a neurological specialist (76%). A small minority of practitioners would provide treatment. Conclusions: There is an overconfidence of the chiropractic practitioner in recognition of MTBI which is incongruent with the low knowledge scores. Further education of the chiropractic clinician is warranted. Trial registration: University Hospital Medical Information Network Clinical Trials Registry. Retrospectively registered (UMIN-CTR), trial number: UMIN#000029744 (Receipt# R000033980) data: October 27, 2017.​Date of enrollment 7/14/2016.

Clinical endpoints in the controlled human challenge model for Shigella: A call for standardization and the development of a disease severity score.

BACKGROUND: Since 1946 the controlled human infection model (CHIM) for Shigella has been used to improve understanding of disease pathogenesis, describe clinical and immunologic responses to infection and as a tool for vaccine development. As the frequency and intent for use in vaccine comparisons increases, standardization of the primary endpoint definition is necessary. METHODS: Subject-level data were obtained from previously conducted experimental Shigella CHIM studies. Signs and symptoms severity were categorized consistently across all studies. Sign and symptom correlations were estimated and univariate models were utilized to describe the association between stool output and other Shigella-attributable signs and symptoms. Multiple correspondence and hierarchical clustering analyses were performed to describe the co-occurrence of signs and symptoms. A disease score is proposed based on the co-occurrence of these events. RESULTS: Data were obtained on 54 subjects receiving 800 to 2000 colony forming units (cfu) of S. flexneri. The median maximum 24 hour stool output was 514 ml (IQR: 300, 998 ml) with a median frequency of 6 (IQR: 4, 9). Subjects reported abdominal pain or cramps (81.5%), headache (66.7%) and anorexia (64.8%), 50.0% had a fever and 27.8% had gross blood in multiple loose stools. Multiple correspondence analyses highlighted co-occurrence of symptoms based on severity. A 3-parameter disease severity score predicted shigellosis endpoints and better differentiated disease spectrum. CONCLUSION: Dichotomous endpoints for Shigella CHIM fail to fully account for disease variability. An ordinal disease score characterizing the breadth of disease severity may enable a better characterization of shigellosis and can decrease sample size requirements. Furthermore, the disease severity score may be a useful tool for portfolio management by enabling prioritization across vaccine candidates with comparable efficacy estimates using dichotomous endpoints.

Medications for the prevention and treatment of travellers' diarrhea.

BACKGROUND: . Travellers' diarrhea (TD) remains one of the most common illnesses encountered by travellers to less developed areas of the world. Because bacterial pathogens such as enterotoxigenic Escherichia coli (ETEC), enteroaggregative E. coli , Campylobacter spp. and Shigella spp. are the most frequent causes, antibiotics have been useful in both prevention and treatment of TD. METHODS.: Results of trials that assessed the use of medications for the prevention and treatment of TD were identified through PubMed and MEDLINE searches using search terms 'travellers' diarrhea', 'prevention' and 'treatment'. References of articles were also screened for additional relevant studies. RESULTS.: Prevention of TD with antibiotics has been recommended only under special circumstances. Doxycycline, trimethoprim-sulfamethoxazole, fluoroquinolones and rifaximin have been used for prevention, but at present the first three antibiotics may have limited use secondary to increasing resistance, leaving rifaximin as the only current option. Bismuth subsalicylate (BSS) (Pepto-Bismol tablets) is also an option for prophylaxis. Treatment with antibiotics has been recommended for moderate to severe TD. Azithromycin is the drug of choice, especially in Asia where Campylobacter is common. Fluoroquinolone antibiotics continue to be effectively used in Latin America and Africa where ETEC is predominant. BSS and loperamide (LOP) also are effective as standalone treatments. LOP may be used alone for treatment of mild TD or in conjunction with antibiotics for treatment of TD. CONCLUSIONS: . Historically, antibiotic prophylaxis has not been routinely recommended and has been reserved for special circumstances such as when a traveller with an underlying illness cannot tolerate TD. Antibiotics with or without LOP have been useful in shortening the duration and severity of TD. Emerging antibiotic resistance, limited new antibiotic alternatives and faecal carriage of antibiotic-resistant bacteria by travellers may prompt a re-evaluation of classic recommendations for treatment and prevention of TD with antibiotics.

Survey of Primary Contact Medical and Chiropractic Clinicians on Self-Reported Knowledge and Recognition of Mild Traumatic Brain Injuries: A Pilot Study.

OBJECTIVE: The purpose of this study was to assess the self-reported knowledge of concussion recognition and treatment with first-contact family medical and chiropractic practitioners by means of a pilot study of the need, construct validity, and feasibility for further investigation of mild traumatic brain injury (MTBI) knowledge base. METHODS: Two hundred forty-eight practicing chiropractic and 120 medical physicians in the south and northeastern sections of the United States were contacted by e-mail, telephone, and postal mail to answer an 18-item survey on knowledge, diagnosis, and common practice with respect to traumatic brain injury patients. Descriptive analysis was used to assess common trends. RESULTS: Twenty-three chiropractic and 11 medical primary care practitioners returned completed surveys, making this a low-power pilot study. The majority claimed confidence in diagnosis of MTBI, but a lack of knowledge of many of the assessment tools and the international guidelines. Chiropractic and medical clinicians revealed similar competencies and differing deficiencies. Both groups admitted infrequent diagnosis of MTBI in practice. There was recognition of major TBI signs, but lack of recognition or inquiry for subtle MTBI signs. CONCLUSIONS: There is a need and feasibility for further study of the knowledge transfer to the chiropractic physician with a larger population. These findings correlate with similar medical practitioner studies, and may also support previous findings of underreporting of the prevalence of MTBI. The survey instrument appears to provide valid data on knowledge of MTBIs, with some modifications.

A Literature Review of Electronic Health Records in Chiropractic Practice: Common Challenges and Solutions.

OBJECTIVE: The purpose of this study was to review the literature on current challenges and propose solutions for the optimal utilization of the electronic health records (EHRs) in chiropractic practice. METHODS: A search was performed in the PubMed, Index of Chiropractic Literature, and Current Index to Nursing and Allied Health Literature databases from November 2005 to February 2015. A combination of the following key words was used: electronic health records, electronic medical records, implementation, documentation, benefits, and challenges. Articles were categorized into common problems and solutions. These were filtered by application to chiropractic or educational institutions. RESULTS: The search resulted in 45 papers, which included case reports of EHR implementation, governmental insurance reports, commentaries, controlled studies, narrative reviews of past experiences with conversion from paper systems, and the implementation of EHRs in small offices and chiropractic offices. Minimal literature was found that directly related to chiropractic EHRs. Improper utilization, incorrect use of the software, faulty implementation, workflow burdens, financial considerations, and insufficient training were found to negatively affect the quality of the record. CONCLUSIONS: Documentation errors are often innate in the EHR software. Improper utilization, insufficient training, or difficulty in integration of the EHR into the clinical office setting results in poor implementation of the electronic version of the clinical record. Solutions that may decrease documentation errors include EHR training, continued financial incentives, and appropriate implementation process and utilization of available software features.

Randomized safety and immunogenicity trial of a seasonal trivalent inactivated split virion influenza vaccine (IVACFLU-S) in healthy young Vietnamese adults.

BACKGROUND: Under the auspices of the World Health Organization (WHO) Global Action Plan, PATH supported evaluation of a trivalent, seasonal inactivated influenza vaccine candidate produced by the Institute of Vaccines and Medical Biologicals (IVAC), a Vietnamese manufacturer. METHODS: In 2015, 60 healthy adult subjects 18-45years of age were enrolled in a Phase 1, single center, double blind, randomized, placebo-controlled study conducted at a district health center in Thai Binh Province, Vietnam. The study evaluated the overall safety and immunogenicity of a seasonal, trivalent inactivated split virion influenza vaccine. Volunteers were given either vaccine or placebo in a randomized 1:1 ratio. After undergoing screening, eligible volunteers provided their signed consent and were enrolled in the study. On the first day of immunization, randomly chosen volunteers received IVACFLU-S 15µg (mcg) hemagglutinin of each of the three strains in 0.5mL or placebo by intramuscular injection. All volunteers were monitored for adverse events and underwent blood testing at screening and Day 8 to assess the vaccine candidate's safety. Sera obtained before and 21days after immunization were tested for influenza antibody titers using the hemagglutination-inhibition (HAI) and microneutralization tests (MNT). RESULTS: Vaccine was well tolerated, and there were no serious adverse events reported. HAI and MNT identified serum antibody responses against the three influenza strains in nearly all volunteers who received the vaccine. Overall, serum HAI responses of fourfold or greater were observed in 93 percent, 83 percent, and 77 percent of H1, H3, and B strains, respectively. Seroprotection rates were also very high. CONCLUSIONS: IVAC's seasonal, trivalent influenza vaccine was safe and well tolerated and induced high levels of seroconversion and seroprotection rates. These clinical data are a first step towards demonstrating the feasibility of producing the vaccine locally and that seasonal vaccine production in Vietnam may be an effective strategy for enhancing the global influenza vaccine supply. ClinicalTrials.gov number NCT02598089, October 15, 2015.

An outbreak of Campylobacter enteritis associated with a community water supply on a U.S. military installation.

An outbreak of acute gastroenteritis involving 249 persons, 32% of whom were hospitalized, occurred on a U.S. Army installation in 1990. Campylobacter jejuni was isolated from 81 of 163 (50%) persons cultured. Seventeen isolates of C. jejuni available for serotyping were Lior serotype 5. The outbreak remained restricted to one recruit barracks area and adjacent Junior Reserve Officer Training Corps cadet barracks. Infection of sequential cohorts of recruits over an interval of 3 weeks suggested a continuing or intermittent common source. Contaminated food was not implicated because affected persons ate at separate dining facilities and other facilities with the same food sources had no associated illnesses. There was a strong association between the amount of water consumed by recruits and risk of diarrhea (chi-square test for trend, p<0.001). Samples of drinking water collected in the affected area had no residual chlorine and when cultured yielded greater than 200 colonies of coliform bacteria per 100 mL of water sampled. Although Campylobacter was not isolated from water, living and dead birds were found in an elevated water storage tank providing drinking water to the affected area. This and other similar outbreaks indicate that contamination of water storage tanks can lead to large outbreaks of Campylobacter enteritis.

Development of VAX128, a recombinant hemagglutinin (HA) influenza-flagellin fusion vaccine with improved safety and immune response.

BACKGROUND: We evaluated the safety and immunogenicity profiles of 3 novel influenza vaccine constructs consisting of the globular head of the HA1 domain of the Novel H1N1 genetically fused to the TLR5 ligand, flagellin. HA1 was fused to the C-terminus of flagellin in VAX128A, replaced the D3 domain of flagellin in VAX128B and was fused in both positions in VAX128C. METHODS: In a dose escalation trial, 112 healthy subjects 18-49 and 100 adults ≥65 years old were enrolled in a double blind, placebo controlled clinical trial at two centers. Vaccines were administered IM at doses ranging from 0.5 to 20 µg. VAX128C was selected for second study performed in 100 subjects 18-64 years old comparing 1.25 and 2.5 µg doses. All subjects were followed for safety and sera collected pre- and post-vaccination were tested by hemagglutination-inhibition (HAI). Serum C-reactive protein and cytokine levels were also measured. CONCLUSIONS: In the first study high HAI titers and high seroconversion and seroprotection rates were observed at doses ≥2.5 µg in adults 18-49. In adults ≥65 years, the vaccines doses of ≥4 µg were required to induce a ≥4-fold rise in HAI titer, 50% seroconversion and 70% seroprotection. Based on safety, VAX128A was tested up to 8 µg, VAX128B to 16 µg and VAX128C to 20 µg. Dose escalation for VAX128A was stopped at 8 µg because one subject had temperature 101.6°F associated with a high CRP response, VAX128B was stopped at 16 µg because of a severe AE associated with a high CRP and IL-6 response. VAX128C was not stopped before reaching the 20 µg dose. In the second study VAX128C was well tolerated among 100 subjects who received 1.25 or 2.5 µg. The peak GMT was 385 (95%CI 272-546), 79% (71-87%) seroconversion and 92% (84-96%) seroprotection. DISCUSSION: Flagellin adjuvanted vaccines can be designed to minimize reactogenicity and retain immunogenicity, thereby representing a promising next generation vaccine technology.

Comparative evaluation of the antibody in lymphocyte supernatant (ALS) and enzyme-linked immunospot (ELISPOT) assays for measuring mucosal immune responses to Shigella antigens.

Accurately assessing mucosal immune responses to candidate vaccines remains a technical challenge. ELISPOT is widely used as a surrogate of mucosal immune response by directly enumerating circulating antibody secreting cells (ASCs), while antibody in lymphocyte supernatant (ALS) titers the total amount of antibody secreted by ASC ex vivo using ELISA. ALS is more practical than ELISPOT because the ASC supernatant is frozen for ELISA that can be conducted at any time, with any antigen, and in any laboratory. We compared IgA and IgG responses to serotype-specific Shigella LPS using ELISPOT and ALS in subjects following vaccination or infection with Shigella. ALS results correlated well with ELISPOT results, and the ALS method was both sensitive and specific for the detection of antibody responses against Shigella LPS. Based on these observations, the ALS assay is a practical and flexible alternative to ELISPOT for measuring mucosal IgA responses to Shigella LPS antigen.

Safety and immunogenicity of a recombinant M2e-flagellin influenza vaccine (STF2.4xM2e) in healthy adults.

BACKGROUND: The ectodomain of matrix protein 2 (M2e) is a promising candidate for a broadly protective influenza A vaccine because it is highly conserved and antibodies to M2e are protective in animal models. STF2.4xM2e (VAX102) is a recombinant fusion protein that links four tandem copies of the M2e antigen to Salmonella typhimurium flagellin, a TLR5 ligand used as an adjuvant. The objectives of this first-in-human study were to assess the safety and immunogenicity of VAX102 given as a prime-boost regimen to healthy adults. METHODS: Sixty subjects 18-49 years old were enrolled in a multicenter, double-blind, randomized, placebo-controlled trial (Study 1). Based on pre-clincial data, initial design included doses starting at 10 µg, with an escalation plan. After reactogenicity was noted at the 10 µg dose, the trial was redesigned to evaluate 0.3, 1.0, and 3 µg doses. Following this study, 16 subjects were enrolled in Study 2, an open label, low dose study, to evaluate doses of 0.03 and 0.1 µg. In both trials, vaccine or placebo was given intramuscularly (i.m.) at 0 and 28 days. Clinical and laboratory safety assessments took place 1 and 7 days after immunization. Immune responses to M2e and flagellin were assessed by ELISA at 7, 14 and 28 days after each dose. Seroconversion was defined as a serum IgG anti-M2e antibody value ≥0.174 µg/ml and a fourfold rise in concentration. RESULTS: Doses of 0.03-1 µg were safe and well tolerated in all subjects. Doses of 0.03 and 0.1 µg produced limited immunogenicity (38% and 75% respectively), after the second dose of vaccine. Doses of 0.3 and 1.0 µg were immunogenic in 18 (75%) of 24 vaccinees after the first dose and 23 (96%) after the second dose. In the 1.0 µg group, the geometric mean M2e antibody concentration was 0.4 µg/ml after the first dose and 1.7 µg/ml after the booster dose. M2e antibody concentrations and seroconversion rates were not significantly different at higher doses (p>0.05). Immune response to flagellin was robust but did not appear to interfere with M2e antibody responses after the booster dose. Following the first injection of VAX102 at higher doses (3 and 10 µg), self-limited but severe symptoms were noted in some subjects and were associated with elevated levels of C-reactive protein. Although not directly measured, this reaction was believed to be mediated by cytokine release. CONCLUSIONS: VAX102 was safe and induced high antibody levels to M2e at 0.3 and 1.0 µg doses. The TLR5 ligand, S. typhimurium flagellin, is a novel approach to adjuvant-like activity through activation of innate immunity, and when fused to multiple copies of the M2e protein, the vaccine was able to induce a fourfold rise in antibody in humans, to a previously non-immunogenic, highly-conserved portion of the influenza virus. Clinical correlates of protection that may be afforded by M2e antibody in humans are a future focus of investigation.

Induction of a potent immune response in the elderly using the TLR-5 agonist, flagellin, with a recombinant hemagglutinin influenza-flagellin fusion vaccine (VAX125, STF2.HA1 SI).

BACKGROUND: Influenza vaccines perform poorly in the elderly with reduced serological response and vaccine efficacy. We evaluated a novel influenza vaccine consisting of the globular head of the HA1 domain of the A/Solomon Islands/3/2006 (H1N1) influenza virus (VAX125) genetically fused to the TLR5 ligand, flagellin, and produced in Escherichia coli. METHODS: 120 subjects ≥ 65 years old were enrolled at three clinical centers. VAX125 vaccine was administered at doses of 0.5, 1, 2, 3, 5 or 8 µg delivered i.m. as a single dose vaccination on Day 0 using a dose-escalation with 20 subjects in each dose level. Subjects were followed for adverse events and sera were tested by hemagglutination-inhibition (HAI) against egg-grown virus on days 0, 7, 14, and 28. Serum C-reactive protein (CRP) and anti-flagellin antibody were also assessed. RESULTS: The mean age was 71 years. The vaccine was well tolerated at all dose levels, with no more than mild to moderate local or systemic symptoms. The geometric mean titers (GMT) increased in all dose groups. In the 5 µg group the day 14 post-vaccination HAI titer was 1:226 showing a 12-fold increase over baseline. The 8 µg group showed a similar post-vaccination GMT increase (∼ 8-fold). In the combined 5 and 8 µg groups, the seroconversion rate was 75% and the seroprotection rate was 98%. CONCLUSIONS: A 5 µg dose of VAX125 was safe and able to induce a greater than 10-fold increase HAI antibody levels and nearly complete seroprotection in subjects over 65 years old. The use of flagellin to adjuvant influenza vaccines via the TLR5 innate immune pathway appears to be a useful approach to overcome poor immune responses in the elderly. VAX125 is a promising new candidate for prevention of influenza A disease in both young adults and the elderly.