Passive Immunization Strategies to Prevent Severe Respiratory Syncytial Virus Infection Among Newborns and Young Infants.

Newborns and young infants are at risk for severe respiratory syncytial virus (RSV) lower respiratory tract infection. Passive immunity is the mainstay of infection prevention in this cohort. Transplacental transfer of maternal antibodies provides the newborn with immediate protection from life-threatening infections, however, is dependent upon gestational age, birth weight, mother's age, recent maternal vaccination, maternal nutritional status, maternal immunocompetence and medical conditions, and placental integrity. Efficient transplacental transfer of RSV-neutralizing antibodies have led to the development and approval of maternal RSV immunization for the protection of the newborn. Additionally, administration of RSV-specific antibodies to infants leads to high serum titers of RSV-neutralizing antibodies and further protection from severe disease.

Influence of AAV vector tropism on long-term expression and Fc-γ receptor binding of an antibody targeting SARS-CoV-2.

Long-acting passive immunization strategies are needed to protect immunosuppressed vulnerable groups from infectious diseases. To further explore this concept for COVID-19, we constructed Adeno-associated viral (AAV) vectors encoding the human variable regions of the SARS-CoV-2 neutralizing antibody, TRES6, fused to murine constant regions. An optimized vector construct was packaged in hepatotropic (AAV8) or myotropic (AAVMYO) AAV capsids and injected intravenously into syngeneic TRIANNI-mice. The highest TRES6 serum concentrations (511 µg/ml) were detected 24 weeks after injection of the myotropic vector particles and mean TRES6 serum concentrations remained above 100 µg/ml for at least one year. Anti-drug antibodies or TRES6-specific T cells were not detectable. After injection of the AAV8 particles, vector mRNA was detected in the liver, while the AAVMYO particles led to high vector mRNA levels in the heart and skeletal muscle. The analysis of the Fc-glycosylation pattern of the TRES6 serum antibodies revealed critical differences between the capsids that coincided with different binding activities to murine Fc-γ-receptors. Concomitantly, the vector-based immune prophylaxis led to protection against SARS-CoV-2 infection in K18-hACE2 mice. High and long-lasting expression levels, absence of anti-drug antibodies and favourable Fc-γ-receptor binding activities warrant further exploration of myotropic AAV vector-based delivery of antibodies and other biologicals.

Economic impact of immunoglobulin replacement therapy in secondary immunodeficiency to hematological cancer: a single center observational study.

This is the first report of the health economic benefits derived from preventing infections through Immunoglobulin Replacement Therapy (IgRT) in patients with secondary immunodeficiency due to hematological malignancies. We conducted a retrospective population-based cohort study using patient medical history and pharmacy data from the Hospital Clínico San Carlos for 21 patients between 2011 and 2020. The pharmacoeconomic impact of using prophylactic IgRT was assessed by comparing characteristics of the SID patients 1 year before and after initiating IgRT measured by direct medical and tangible indirect costs. Results indicate a marked reduction in hospitalization days following IgRT initiation, decreasing from an average of 13.9 to 6.1 days per patient, with the elimination of ICU admissions. While emergency department visits decreased significantly, the number of routine consultations remained unchanged. Notably, absenteeism from work dropped substantially. The financial analysis revealed significant reductions in medication use and fewer ancillary tests, resulting in considerable cost savings. Specifically, total expenditure dropped from €405,088.18 pre-IgRT to €295,804.42 post-IgRT-including the cost of IgRT itself at €156,309.60. Overall, the annual savings amounted to €109,283.84, validating the cost-effectiveness of IgRT in managing SID in patients with hematological cancers.

RSV Prevention Within Reach for Older Infants and Toddlers: The Role of Active Immunization.

This review article will summarize the vaccines and monoclonal antibodies currently under evaluation for the prevention of RSV disease in older infants, toddlers and young children. We will review the rationale for passive protection during the first months of life, and the role of active immunization afterwards, either with live attenuated, protein-based or mRNA vaccines.

The Use of Broadly Neutralizing Antibodies (bNAbs) in HIV-1 Treatment and Prevention.

BACKGROUND: Although antiretroviral therapy (ART) effectively halts disease progression in HIV infection, the complete eradication of the virus remains elusive. Additionally, challenges such as long-term ART toxicity, drug resistance, and the demanding regimen of daily and lifelong adherence required by ART highlight the imperative need for alternative therapeutic and preventative approaches. In recent years, broadly neutralizing antibodies (bNAbs) have emerged as promising candidates, offering potential for therapeutic, preventative, and possibly curative interventions against HIV infection. OBJECTIVE: This review aims to provide a comprehensive overview of the current state of knowledge regarding the passive immunization of bNAbs in HIV-1-infected individuals. MAIN FINDINGS: Recent findings from clinical trials have highlighted the potential of bNAbs in the treatment, prevention, and quest for an HIV-1 cure. While monotherapy with a single bNAb is insufficient in maintaining viral suppression and preventing viral escape, ultimately leading to viral rebound, combination therapy with potent, non-overlapping epitope-targeting bNAbs have demonstrated prolonged viral suppression and delayed time to rebound by effectively restricting the emergence of escape mutations, albeit largely in individuals with bNAb-sensitive strains. Additionally, passive immunization with bNAb has provided a "proof of concept" for antibody-mediated prevention against HIV-1 acquisition, although complete prevention has not been obtained. Therefore, further research on the use of bNAbs in HIV-1 treatment and prevention remains imperative.

Association between COVID-19 convalescent plasma antibody levels and COVID-19 outcomes stratified by clinical status at presentation.

BACKGROUND: There is a need to understand the relationship between COVID-19 Convalescent Plasma (CCP) anti-SARS-CoV-2 IgG levels and clinical outcomes to optimize CCP use. This study aims to evaluate the relationship between recipient baseline clinical status, clinical outcomes, and CCP antibody levels. METHODS: The study analyzed data from the COMPILE study, a meta-analysis of pooled individual patient data from 8 randomized clinical trials (RCTs) assessing the efficacy of CCP vs. control, in adults hospitalized for COVID-19 who were not receiving mechanical ventilation at randomization. SARS-CoV-2 IgG levels, referred to as 'dose' of CCP treatment, were retrospectively measured in donor sera or the administered CCP, semi-quantitatively using the VITROS Anti-SARS-CoV-2 IgG chemiluminescent immunoassay (Ortho-Clinical Diagnostics) with a signal-to-cutoff ratio (S/Co). The association between CCP dose and outcomes was investigated, treating dose as either continuous or categorized (higher vs. lower vs. control), stratified by recipient oxygen supplementation status at presentation. RESULTS: A total of 1714 participants were included in the study, 1138 control- and 576 CCP-treated patients for whom donor CCP anti-SARS-CoV2 antibody levels were available from the COMPILE study. For participants not receiving oxygen supplementation at baseline, higher-dose CCP (/control) was associated with a reduced risk of ventilation or death at day 14 (OR = 0.19, 95% CrI: [0.02, 1.70], posterior probability Pr(OR < 1) = 0.93) and day 28 mortality (OR = 0.27 [0.02, 2.53], Pr(OR < 1) = 0.87), compared to lower-dose CCP (/control) (ventilation or death at day 14 OR = 0.79 [0.07, 6.87], Pr(OR < 1) = 0.58; and day 28 mortality OR = 1.11 [0.10, 10.49], Pr(OR < 1) = 0.46), exhibiting a consistently positive CCP dose effect on clinical outcomes. For participants receiving oxygen at baseline, the dose-outcome relationship was less clear, although a potential benefit for day 28 mortality was observed with higher-dose CCP (/control) (OR = 0.66 [0.36, 1.13], Pr(OR < 1) = 0.93) compared to lower-dose CCP (/control) (OR = 1.14 [0.73, 1.78], Pr(OR < 1) = 0.28). CONCLUSION: Higher-dose CCP is associated with its effectiveness in patients not initially receiving oxygen supplementation, however, further research is needed to understand the interplay between CCP anti-SARS-CoV-2 IgG levels and clinical outcome in COVID-19 patients initially receiving oxygen supplementation.

[The use of immunoglobulins and monoclonal antibodies against COVID-19].

INTRODUCTION: When a new disease occurs, one of the most affordable remedies is drugs containing specific antibodies to this infectious agent. The use of such drugs is aimed at reducing the amount of the pathogen in the macroorganism and the associated reduction in the severity of the symptoms of the disease or recovery. The purpose of this review is to analyze the experience of using immunoglobulins and monoclonal antibodies in the treatment of COVID-19 patients during the pandemic. RESULTS AND CONCLUSION: The two main groups of medical protective agents that block the penetration of the SARS-CoV-2 virus into permissive cells are drugs obtained from blood plasma of convalescents (immunoglobulin) and human monoclonal antibodies. The first group of drugs in the treatment of COVID-19 includes blood plasma of convalescents, which can be successfully used for emergency prevention. The main disadvantage of using blood plasma convalescents is the difficulty of standardization due to the different content of specific antibodies in donors. Another disadvantage is the undesirable side effects in recipients that occur after plasma administration. An alternative approach to COVID-19 therapy is the use of humanized and genetically engineered human monoclonal antibodies against certain epitopes of the SARS-CoV-2 virus. For example, monoclonal antibodies against receptor-binding domain of the S-protein, which prevents the virus from entering permissive cells and interrupts the development of infection. The advantages of these drugs are their safety, high specific activity, and the possibility of standardization. However, the complexity of their production and high cost make them inaccessible for mass use in practical medicine.

Characteristics of failure of passive transfer at the herd level using the serum immunoglobulin G concentration as an indicator on dairy farms in eastern Hokkaido, Japan.

The objectives of this study were to conduct a survey of failure-of-passive-transfer (FPT) in eastern Hokkaido Japan, to evaluate the association between herd-level FPT and death and culling or treatment, and to test the effectiveness of monitoring using herd-level FPT. A total of 4,411 Holstein and Holstein-Wagyu crossbreds calves born from Holstein dams during the year beginning April 2, 2019 on 39 dairy farms were included in the study to investigate death-and-culling and the treatment rate during the first month of life, as well as rearing management up to 3 weeks of age. A subset of Holsteins (n=381) was included in the study for passive transfer and farms were diagnosed as having FPT if more than 20% of newborn calves had serum IgG levels below 10 g/L at the herd level. The prevalence of FPT (

Passive immunotherapy for Alzheimer's disease: challenges & future directions.

Passive immunotherapy with specific antibodies targeting Amyloid ß (Aß) peptide or tubulin-associated unit (tau) protein has emerged as a promising therapeutic approach in Alzheimer's disease (AD). However, in a recent phase III clinical study, Sperling et al. (N Engl J Med 10.1056/NEJMoa2305032, 2023) reported that solanezumab, a monoclonal antibody targeting Aß peptide, failed to slow cognitive decline in AD patients. Previously, three other anti-Aß antibodies, bapineuzumab, crenezumab, and gantenerumab, have also failed to show similar beneficial effects. In addition, three humanized antibodies targeting tau protein failed in their phase II trials. However, other anti-Aß antibodies, such as lecanemab (a humanized mAb binds to soluble Aß protofibrils), donanemab (a humanized mAb binds to insoluble, N-terminal truncated form of Aß peptides) and aducanumab (a human mAb binds to the aggregated form of Aß), have been shown to slow the decline of cognitive functions in early stage AD patients. The specific targets used in passive immunotherapy in these clinical trials may explain the divergent clinical outcomes. There are several challenges and limitations of passive immunotherapy using anti-Aß antibodies and long term longitudinal studies are needed to assess their efficacy, side effects and cost effectiveness in a wider spectrum of subjects, from pre-dementia to more advanced dementia. A combination therapeutic approach using both anti-Aß antibodies and other pharmaceutical agents should also be explored.

The Effects of Convalescent Plasma Transfusion on Serum Levels of Macrophage-Associated Inflammatory Biomarkers in Patients with Severe COVID-19.

As an antibody-based therapy, plasma therapy has been used as an emergency therapeutic strategy against severe acute respiratory syndrome coronavirus type 2 infection. Due to the critical role of macrophages in coronavirus disease-19 (COVID-19)-associated hyperinflammation, the main objective of this study was to assess the effect of plasma transfusion on the expression levels of the inflammatory biomarkers involved in activation and pulmonary infiltration of macrophages. The target population included 50 severe hospitalized COVID-19 patients who were randomly assigned into 2 groups, including intervention and control. Serum levels of chemokine (C-C motif) ligand (CCL)-2, CCL-3, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were measured by enzyme-linked immunosorbent assay. Moreover, quantitative real-time polymerase chain reaction (PCR) was carried out to assess the relative expression of nuclear factor (NF)-κB1, NF-κB2, nuclear factor erythroid 2 p45-related factor 2 (NRF-2), and thioredoxin-interacting protein genes. Sampling was done at baseline and 72 h after receiving plasma. The intervention group demonstrated significantly lower serum levels of IL-6, TNF-α, and CCL-3. In addition, real-time PCR data analyses showed that the relative expression of NF-κB2 was significantly declined in the patients who received plasma. The use of convalescent plasma probably has a significant inhibitory effect on the cytokines, chemokines, and inflammatory genes related to macrophage activation, which are closely associated with the worsening of clinical outcomes in severe COVID-19.

Acute Aseptic Meningitis Temporally Associated with Intravenous Polyclonal Immunoglobulin Therapy: A Systematic Review.

An acute aseptic meningitis has been occasionally observed on intravenous polyclonal human immunoglobulin therapy. Since case reports cannot be employed to draw inferences about the relationships between immunoglobulin therapy and meningitis, we conducted a systematic review and meta-analysis of the literature. Eligible were cases, case series, and pharmacovigilance studies. We found 71 individually documented cases (36 individuals ≤ 18 years of age) of meningitis. Ninety percent of cases presented ≤ 3 days after initiating immunoglobulin therapy and recovered within ≤ 7 days (with a shorter disease duration in children: ≤ 3 days in 29 (94%) cases). In 22 (31%) instances, the authors noted a link between the onset of meningitis and a rapid intravenous infusion of immunoglobulins. Cerebrospinal fluid analysis revealed a predominantly neutrophilic (N = 46, 66%) pleocytosis. Recurrences after re-exposure were observed in eight (N = 11%) patients. Eight case series addressed the prevalence of meningitis in 4089 patients treated with immunoglobulins. A pooled prevalence of 0.6% was noted. Finally, pharmacovigilance data revealed that meningitis temporally associated with intravenous immunoglobulin therapy occurred with at least five different products. In conclusion, intravenous immunoglobulin may cause an acute aseptic meningitis. The clinical features remit rapidly after discontinuing the medication.

New technologies in therapeutic antibody development: The next frontier for treating infectious diseases.

Adaptive immunity to viral infections requires time to neutralize and clear viruses to resolve infection. Fast growing and pathogenic viruses are quickly established, are highly transmissible and cause significant disease burden making it difficult to mount effective responses, thereby prolonging infection. Antibody-based passive immunotherapies can provide initial protection during acute infection, assist in mounting an adaptive immune response, or provide protection for those who are immune suppressed or immune deficient. Historically, plasma-derived antibodies have demonstrated some success in treating diseases caused by viral pathogens; nonetheless, limitations in access to product and antibody titer reduce success of this treatment modality. Monoclonal antibodies (mAbs) have proven an effective alternative, as it is possible to manufacture highly potent and specific mAbs against viral targets on an industrial scale. As a result, innovative technologies to discover, engineer and manufacture specific and potent antibodies have become an essential part of the first line of treatment in pathogenic viral infections. However, a mAb targeting a specific epitope will allow escape variants to outgrow, causing new variant strains to become dominant and resistant to treatment with that mAb. Methods to mitigate escape have included combining mAbs into cocktails, creating bi-specific or antibody drug conjugates but these strategies have also been challenged by the potential development of escape mutations. New technologies in developing antibodies made as recombinant polyclonal drugs can integrate the strength of poly-specific antibody responses to prevent mutational escape, while also incorporating antibody engineering to prevent antibody dependent enhancement and direct adaptive immune responses.

Treatment of chronic COVID-19 with convalescent/postvaccination plasma in patients with hematologic malignancies.

Immunocompromised patients are at high risk to fail clearance of SARS-CoV-2. Prolonged COVID-19 constitutes a health risk and a management problem as cancer treatments often have to be disrupted. As SARS-CoV-2 evolves, new variants of concern have emerged that evade available monoclonal antibodies. Moreover, antiviral therapy promotes SARS-CoV-2 escape mutations, particularly in immunocompromised patients. These patients frequently suffer from prolonged infection. No successful treatment has been established for persistent COVID-19 infection. Here, we report on a series of 21 immunocompromised patients with COVID-19-most of them hematologic malignancies-treated with plasma obtained from recently convalescent or vaccinated donors or a combination thereof. Repeated dosing of SARS-CoV-2-antibody-containing plasma could clear SARS-CoV-2 infection in 16 out of 21 immunocompromised patients even if COVID-19-specific treatments failed to induce sustained viral clearance or to improve clinical course of SARS-CoV-2 infection. Ten patients were major responders defined as an increase delta(d)Ct of > = 5 after the first administration of convalescent and/or vaccinated plasma (C/VP). On average, SARS-CoV-2 PCR Ct values increased from a median value of 22.55 (IQR = 19.10-24.25) to a median value of 29.57 (IQR = 27.55-34.63; p = <.0001) in the major response subgroup. Furthermore, when treated a second time with C/VP, even 4 out of 5 of the initial nonresponders showed an increase in Ct-values from a median value of 23.13 (IQR = 17.75-28.05) to a median value of 32.79 (IQR = 31.75-33.75; p = .013). Our results suggest that C/VP could be a feasible treatment of COVID-19 infection in patients with hematologic malignancies who did not respond to antiviral treatment.

A Public Option for Clinical Trials? Lessons from Convalescent Plasma.

The case of clinical trials for convalescent plasma during COVID-19 illustrates important lessons for realizing public sector approaches to biomedical research and development. These lessons, centering on mission, transparency, and spillover effects, can be translated to wider efforts to develop a "public option" for clinical trials.

Intravenous immunoglobulins for the treatment of prolonged COVID-19 in immunocompromised patients: a brief report.

Primary humoral deficiency and secondary B-cell depletion may lead to prolonged Sars-Cov-2 infection due to a decreased viral clearance. Prolonged infection is mainly driven by the lack of anti-Sars-Cov-2 immunoglobulin (IVIg) especially in patients with no vaccine response. Anti-spike immunoglobulin can be provided by infusion of convalescent patients' plasma: recent studies highlighted that commercial immunoglobulin show high titers of neutralizing IgG. We conducted a single center retrospective cohort. We included 9 patients (6 males, median age 74 years old): one patient with X-linked agammaglobulinemia and 8 patients treated with rituximab (2 granulomatosis with polyangiitis, 1 neuromyelitis optica, 4 low grade B-cell lymphoma and 1 EBV post-transplant lymphoproliferative disorder). Mean serum globulin was 4 ± 1.6 g/L. 7/8 had received at least 3 doses of mRNA anti-Sars-Cov-2 vaccine (median 4) with no response (anti-Spike IgG 0 for 6 patients). In this specific population requiring oxygen therapy but no intensive care support, the administration of IVIg was well tolerated and provided a swift improvement of clinical status, a significant decrease of inflammation associated to the an improvement of radiological patterns. Our results suggest that immunoglobulin could be used as a salvage therapy as an alternative to convalescent plasma but highly stringent patient selection is required due to the worldwide shortage of IVIg.

Relationships between bronchiectasis and time to achieving target trough immunoglobulin G levels in patients with common variable immunodeficiency.

Background: The main treatment of common variable immunodeficiency (CVID) is to maintain immunoglobulin G (IgG) levels within the target range. However, trough IgG levels differ among patients with similar body mass index (BMI) and those receiving the same dose of immunoglobulin replacement therapy (IGRT). A crucial factor that underlies these differences is the presence of extensive bronchiectasis, which is associated with the immunoglobulin salvage pathway. Objective: We compared trough IgG levels in patients with CVID and with and in those without bronchiectasis who had received the same dose of IGRT for 2 years to determine the association of IgG level with infection frequency. Method: This retrospective cohort study included 61 patients with CVID, of whom 21 had bronchiectasis. We reviewed the electronic records for demographic variables, baseline immunoglobulin levels, mean trough IgG levels over 2 years, efficacy levels (trough IgG level - baseline IgG level), the time interval from treatment initiation to achieving the target trough IgG level (700 mg/dL), and the number of infections. Results: The median age of the patients was 39 years (IQR, 27-51), and 29 were women (47.5%). There were no significant differences between the groups in terms of age, age at diagnosis, delay in diagnosis, sex, BMI, IGRT type (subcutaneous or intravenous), and baseline immunoglobulin levels. Trough IgG and efficacy levels were lower (P < 0.001 and P = 0.016, respectively), the time required to achieve the target IgG level was longer in patients with bronchiectasis than in those without bronchiectasis, and this time interval was significantly associated with the infection frequency. Trough IgG and albumin levels were correlated (p = 0.007), with minor differences between the groups (p = 0.04). Conclusion: Bronchiectasis was significantly associated with a longer time to achieve the target IgG levels. These long-term differences between the patients with and those without bronchiectasis have significant clinical implications.

"A Most Equitable Drug": How the Clinical Studies of Convalescent Plasma as a Treatment for SARS-CoV-2 Might Usefully Inform Post-Pandemic Public Sector Approaches to Drug Development.

Interventional clinical studies of convalescent plasma to treat COVID-19 were predominantly funded and led by public sector actors, including blood services operators. We aimed to analyze the processes of clinical studies of convalescent plasma to understand alternatives to pharmaceutical industry biopharmaceutical research and development, particularly where public sector actors play a dominant role. We conducted a qualitative, critical case study of purposively sampled prominent and impactful clinical studies of convalescent plasma during 2020-2021.

Treatment and Vaccination for Smallpox and Monkeypox.

The smallpox infection with the variola virus was one of the most fatal disorders until a global eradication was initiated in the twentieth century. The last cases were reported in Somalia 1977 and as a laboratory infection in the UK 1978; in 1980, the World Health Organization (WHO) declared smallpox for extinct. The smallpox virus with its very high transmissibility and mortality is still a major biothreat, because the vaccination against smallpox was stopped globally in the 1980s. For this reason, new antivirals (cidofovir, brincidofovir, and tecovirimat) and new vaccines (ACAM2000, LC16m8 and Modified Vaccine Ankara MVA) were developed. For passive immunization, vaccinia immune globulin intravenous (VIGIV) is available. Due to the relationships between orthopox viruses such as vaccinia, variola, mpox (monkeypox), cowpox, and horsepox, the vaccines (LC16m8 and MVA) and antivirals (brincidofovir and tecovirimat) could also be used in the mpox outbreak with positive preliminary data. As mutations can result in drug resistance against cidofovir or tecovirimat, there is need for further research. Further antivirals (NIOCH-14 and ST-357) and vaccines (VACΔ6 and TNX-801) are being developed in Russia and the USA. In conclusion, further research for treatment and prevention of orthopox infections is needed and is already in progress. After a brief introduction, this chapter presents the smallpox and mpox disease and thereafter full overviews on antiviral treatment and vaccination including the passive immunization with vaccinia immunoglobulins.

Change of voltage-gated sodium channel repertoire in skeletal muscle of a MuSK myasthenia gravis mouse model.

Muscle-specific kinase myasthenia gravis (MuSK MG) is caused by autoantibodies against MuSK in the neuromuscular junction (NMJ). MuSK MG patients have fluctuating, fatigable skeletal muscle weakness, in particular of bulbar muscles. Severity differs greatly between patients, in spite of comparable autoantibody levels. One explanation for inter-patient and inter-muscle variability in sensitivity might be variations in compensatory muscle responses. Previously, we developed a passive transfer mouse model for MuSK MG. In preliminary ex vivo experiments, we observed that muscle contraction of some mice, in particular those with milder myasthenia, had become partially insensitive to inhibition by µ-Conotoxin-GIIIB, a blocker of skeletal muscle NaV1.4 voltage-gated sodium channels. We hypothesised that changes in NaV channel expression profile, possibly co-expression of (µ-Conotoxin-GIIIB insensitive) NaV1.5 type channels, might lower the muscle fibre's firing threshold and facilitate neuromuscular synaptic transmission. To test this hypothesis, we here performed passive transfer in immuno-compromised mice, using 'high', 'intermediate' and 'low' dosing regimens of purified MuSK MG patient IgG4. We compared myasthenia levels, µ-Conotoxin-GIIIB resistance and muscle fibre action potential characteristics and firing thresholds. High- and intermediate-dosed mice showed clear, progressive myasthenia, not seen in low-dosed animals. However, diaphragm NMJ electrophysiology demonstrated almost equal myasthenic severities amongst all regimens. Nonetheless, low-dosed mouse diaphragms showed a much higher degree of µ-Conotoxin-GIIIB resistance. This was not explained by upregulation of Scn5a (the NaV1.5 gene), lowered muscle fibre firing thresholds or histologically detectable upregulated NaV1.5 channels. It remains to be established which factors are responsible for the observed µ-Conotoxin-GIIIB insensitivity and whether the NaV repertoire change is compensatory beneficial or a bystander effect.

A Historical Perspective on Respiratory Syncytial Virus Prevention: A Journey Spanning Over Half a Century From the Setback of an Inactive Vaccine Candidate to the Success of Passive Immunization Strategy.

The efforts to prevent respiratory syncytial virus (RSV) infection in infants span over half a century. RSV vaccine development began in the 1960s, and it confronted a significant disappointment after testing a formalin-inactivated RSV (FI RSV) vaccine candidate. This inactivated RSV vaccine was not protective. A large number of the vaccinated RSV-naive children, when subsequently exposed to natural RSV infection from wild-type virus in the community, developed severe lung inflammation termed enhanced respiratory disease. This resulted in a halt in RSV vaccine development. In the 1990s, attention turned to the potential for passive protection against severe RSV disease with immunoglobulin administration. This led to studies on using standard intravenous immunoglobulins in high-risk infants, followed by high-titer RSV immunoglobulin preparation and, subsequently, the development of RSV monoclonal antibodies. Over the past 25 years, palivizumab has been recognized as a safe and effective monoclonal antibody as a prevention strategy for RSV in high-risk children. Its high cost and need for monthly administration, however, has hindered its use to ~2% of the birth cohort, neglecting the vast majority of newborns, including healthy full-term infants who comprise the largest portion of RSV hospitalizations and the greatest part of the burden of RSV disease. Still these efforts, helped pave the way for the present advances in RSV prevention that hold promise for mitigating severe RSV disease for all infants.