Neutralizing Activity and SARS-CoV-2 Vaccine mRNA Persistence in Serum and Breastmilk After BNT162b2 Vaccination in Lactating Women

BackgroundThere is limited information on the functional neutralizing capabilities of breastmilk SARS-CoV-2-specific antibodies and the potential adulteration of breastmilk with vaccine mRNA after SARS-CoV-2 mRNA vaccination.MethodsWe conducted a prospective cohort study of lactating healthcare workers who received the BNT162b2 vaccine and their infants. The presence of SARS-CoV-2 neutralizing antibodies, antibody isotypes (IgG, IgA, IgM) and intact mRNA in serum and breastmilk was evaluated at multiple time points using a surrogate neutralizing assay, ELISA, and PCR, over a 6 week period of the two-dose vaccination given 21 days apart.ResultsThirty-five lactating mothers, median age 34 years (IQR 32-36), were included. All had detectable neutralizing antibodies in the serum immediately before dose 2, with significant increase in neutralizing antibody levels 7 days after this dose [median 168.4 IU/ml (IQR 100.7-288.5) compared to 2753.0 IU/ml (IQR 1627.0-4712.0), p <0.001]. Through the two vaccine doses, all mothers had detectable IgG1, IgA and IgM isotypes in their serum, with a notable increase in all three antibody isotypes after dose 2, especially IgG1 levels. Neutralizing antibodies were detected in majority of breastmilk samples a week after dose 2 [median 13.4 IU/ml (IQR 7.0-28.7)], with persistence of these antibodies up to 3 weeks after. Post the second vaccine dose, all (35/35, 100%) mothers had detectable breastmilk SARS-CoV-2 spike RBD-specific IgG1 and IgA antibody and 32/35 (88.6%) mothers with IgM. Transient, low intact vaccine mRNA levels was detected in 20/74 (27%) serum samples from 21 mothers, and 5/309 (2%) breastmilk samples from 4 mothers within 1 weeks of vaccine dose. Five infants, median age 8 months (IQR 7-16), were also recruited - none had detectable neutralizing antibodies or vaccine mRNA in their serum.ConclusionMajority of lactating mothers had detectable SARS-CoV-2 antibody isotypes and neutralizing antibodies in serum and breastmilk, especially after dose 2 of BNT162b2 vaccination. Transient, low levels of vaccine mRNA were detected in the serum of vaccinated mothers with occasional transfer to their breastmilk, but we did not detect evidence of infant sensitization. Importantly, the presence of breastmilk neutralising antibodies likely provides a foundation for passive immunisation of the breastmilk-fed infant.

Persistent SARS-CoV-2 Infection in Patients With Secondary Antibody Deficiency: Successful Clearance Following Combination Casirivimab and Imdevimab (REGN-COV2) Monoclonal Antibody Therapy

Background There is growing evidence that antibody responses play a role in the resolution of SARS-CoV-2 infection. Patients with primary or secondary antibody deficiency are at increased risk of persistent infection. This challenging clinical scenario is associated with adverse patient outcome and potentially creates an ecological niche for the evolution of novel SARS-CoV-2 variants with immune evasion capacity. Case reports and/or series have implied a therapeutic role for passive immunisation with convalescent plasma (CP) to secure virological clearance, although concerns have been raised about the effectiveness of CP and its potential to drive viral evolution, and it has largely been withdrawn from clinical use in the UK. Case presentation: We report two cases in which persistent SARS-CoV-2 infection was cleared following administration of the monoclonal antibody combination casirivimab and imdevimab (REGN-COV2, Ronapreve). A 55-year-old male with follicular lymphoma, treated with B cell depleting therapy, developed SARS-CoV-2 infection in September 2020 which then persisted for over 200 days. He was hospitalised on four occasions with COVID-19 and suffered debilitating fatigue and malaise throughout. There was no clinical response to antiviral therapy with remdesivir or CP, and SARS-CoV-2 was consistently detected in nasopharyngeal swabs. Intrahost evolution of several spike variants of uncertain significance was identified by viral sequence analysis. Delivery of REGN-COV2, in combination with remdesivir, was associated with clinical improvement and viral clearance within 6 days, which was sustained for over 150 days despite immunotherapy for relapsed follicular lymphoma. The second case, a 68-year-old female with chronic lymphocytic leukaemia on ibrutinib, also developed persistent SARS-CoV-2 infection. Despite a lack of response to remdesivir, infection promptly cleared following REGN-COV2 in combination with remdesivir, accompanied by resolution of inflammation and full clinical recovery that has been maintained for over 290 days. Conclusions These cases highlight the potential benefit of REGN-COV2 as therapy for persistent SARS-CoV-2 infection in antibody deficient individuals, including after failure of CP treatment. Formal clinical studies are warranted to assess the effectiveness of REGN-COV2 in antibody-deficient patients.

Amyloid-β and α-Synuclein Immunotherapy: From Experimental Studies to Clinical Trials

Alzheimer’s disease and Lewy body diseases are the most common causes of neurodegeneration and dementia. Amyloid-beta (Aβ) and alpha-synuclein (αSyn) are two key proteins involved in the pathogenesis of these neurodegenerative diseases. Immunotherapy aims to reduce the harmful effects of protein accumulation by neutralising toxic species and facilitating their removal. The results of the first immunisation trial against Aβ led to a small percentage of meningoencephalitis cases which revolutionised vaccine design, causing a shift in the field of immunotherapy from active to passive immunisation. While the vast majority of immunotherapies have been developed for Aβ and tested in Alzheimer’s disease, the field has progressed to targeting other proteins including αSyn. Despite showing some remarkable results in animal models, immunotherapies have largely failed final stages of clinical trials to date, with the exception of Aducanumab recently licenced in the US by the FDA. Neuropathological findings translate quite effectively from animal models to human trials, however, cognitive and functional outcome measures do not. The apparent lack of translation of experimental studies to clinical trials suggests that we are not obtaining a full representation of the effects of immunotherapies from animal studies. Here we provide a background understanding to the key concepts and challenges involved in therapeutic design. This review further provides a comprehensive comparison between experimental and clinical studies in Aβ and αSyn immunotherapy and aims to determine the possible reasons for the disconnection in their outcomes.

Study Pre-protocol for “BronchStart - The Impact of the COVID-19 Pandemic on the Timing, Age and Severity of Respiratory Syncytial Virus (RSV) Emergency Presentations; a Multi-Centre Prospective Observational Cohort Study”

Background: Bronchiolitis (most frequently caused by respiratory syncytial virus; RSV) is a common winter disease predominantly affecting children under one year of age. It is a common reason for presentations to an emergency department (ED) and frequently results in hospital admission, contributing to paediatric units approaching or exceeding capacity each winter. During the SARS-CoV-2 pandemic, the circulation of RSV was dramatically reduced in the United Kingdom and Ireland. Evidence from the Southern Hemisphere and other European countries suggests that as social distancing restrictions for SARS-CoV-2 are relaxed, RSV infection returns, causing delayed or even summer epidemics, with different age distributions. Study question: The ability to track, anticipate and respond to a surge in RSV cases is critical for planning acute care delivery. There is an urgent need to understand the onset of RSV spread at the earliest opportunity. This will influence service planning, to inform clinicians whether the population at risk is a wider age range than normal, and whether there are changes in disease severity. This information is also needed to inform decision on the timing of passive immunisation of children at higher risk of hospitalisation, intensive care admission or death with RSV infection, which is a public health priority. Methods and likely impact: This multi-centre prospective observational cohort study will use a well-established research network (Paediatric Emergency Research in the UK and Ireland, PERUKI) to report in real time cases of RSV infection in children aged under two years, through the collection of essential, but non-identifying patient information. Forty-five centres will gather initial data on age, index of multiple deprivation quintile, clinical features on presentation, and co-morbidities. Each case will be followed up at seven days to identify treatment, viral diagnosis and outcome. Information be released on a weekly basis and used to support clinical decision making.

Study Pre-protocol for 'BronchStart - The Impact of the COVID-19 Pandemic on the Timing, Age and Severity of Respiratory Syncytial Virus (RSV) Emergency Presentations; a Multi-Centre Prospective Observational Cohort Study'

Background Bronchiolitis (most frequently caused by Respiratory Syncytial Virus; RSV) is a common winter disease predominantly affecting children under one year of age. It is a common reason for presentations to an Emergency Department (ED) and frequently results in hospital admission, contributing to paediatric units approaching or exceeding capacity each winter. During the SARS-CoV-2 pandemic, the circulation of RSV was dramatically reduced in the United Kingdom and Ireland. Evidence from the Southern Hemisphere and other European countries suggests that as social distancing restrictions for SARS-CoV-2 are relaxed, RSV infection returns, causing delayed or even summer epidemics, with different age distributions. Study question The ability to track, anticipate and respond to a surge in RSV cases is critical for planning acute care delivery. There is an urgent need to understand the onset of RSV spread at the earliest opportunity. This will influence service planning, to inform clinicians whether the population at risk is a wider age range than normal, and whether there are changes in disease severity. This information is also needed to inform decision on the timing of passive immunisation of children at higher risk of hospitalisation, intensive care admission or death with RSV infection, which is a public health priority. Methods and likely impact This multi-centre prospective observational cohort study will use a well-established research network (Paediatric Emergency Research in the UK and Ireland, PERUKI) to report in real time cases of RSV infection in children aged under two years, through the collection of essential, but non-identifying patient information. Forty centres will gather initial data on age, index of multiple deprivation quintile, clinical features on presentation, and co-morbidities. Each case will be followed up at 7 days to identify treatment, viral diagnosis and outcome. Information be released on a weekly basis and used to support clinical decision making.

Tau antibody isotype induces differential effects following passive immunisation of tau transgenic mice

One of the main pathological hallmarks of Alzheimer’s disease (AD) is the intraneuronal accumulation of hyperphosphorylated tau. Passive immunotherapy is a promising strategy for the treatment of AD and there are currently a number of tau-specific monoclonal antibodies in clinical trials. A proposed mechanism of action is to engage and clear extracellular, pathogenic forms of tau. This process has been shown in vitro to be facilitated by microglial phagocytosis through interactions between the antibody-tau complex and microglial Fc-receptors. As this interaction is mediated by the conformation of the antibody's Fc domain, this suggests that the antibody isotype may affect the microglial phagocytosis and clearance of tau, and hence, the overall efficacy of tau antibodies. We therefore aimed to directly compare the efficacy of the tau-specific antibody, RN2N, cloned into a murine IgG1/κ framework, which has low affinity Fc-receptor binding, to that cloned into a murine IgG2a/κ framework, which has high affinity Fc-receptor binding. Our results demonstrate, for RN2N, that although enhanced microglial activation via the IgG2a/κ isotype increased extracellular tau phagocytosis in vitro, the IgG1/κ isoform demonstrated enhanced ability to reduce tau pathology and microgliosis following passive immunisation of the P301L tau transgenic pR5 mouse model.

Covid 19-the 21st Century Pandemic: The Novel Coronavirus Outbreak and the Treatment Strategies

COVID -19 a global pandemic that has brought all the greater global countries to a hook. The novel coronavirus (SARS-CoV-2) outbreak was first reported in Wuhan, China which then started spreading to different countries around the world. ACE2 receptors are present in various organs but the overexpression of ACE2 at lung epithelia makes them more vulnerable to respiratory symptoms. SARS-CoV-2 binds to ACE2 receptors for entry into host cells which may serve as potential target for future therapy .Repurposing of drugs are the present strategy undertaken as the SARS-CoV-2 shows similar respiratory distress symptoms as in the case of SARS and MERS. At present the antiviral medications and vaccines are at the early stages and may take few months to years, to achieve their complete efficacy to solve the public crisis. The technological advancements have brought passive immunisation, which is an anecdotal success, but the ideal approach to future outbreaks of SARS-CoV-2 is done by vaccines that are under clinical trials. There are a large percentage of population under psychological crisis either due to the fear of infection or stress from the quarantine lives. High levels of viral loads at the initial stages cause higher chances of transmission hence immediate isolations and screening methods must be undertaken. This review mainly focuses on the treatment strategies followed with no definitive approval from authorities. This is an attempt to gather all the materialistic evidences available for now.

Convalescent COVID-19 plasma

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a new human disease. December 31, 2019 marked the day the World Health Organization (WHO) first became aware of an infectious outbreak in the Hubei province in China. Until January 2021, more than two million people died from COVID-19. The use of convalescent plasma (CP) has been widely used in different outbreaks as the first therapeutic option given the lack of effective medications or vaccines, and often as a last chance or experimental treatment. CP is a strategy of passive immunisation. Possible mechanisms of CP-COVID-19 action are antiviral and immunomodulatory. The established protocol for CP-COVID-19 collection defines activities and criteria related to recruiting and informing potential CP donors, clinical and laboratory examination, plasma collection, labelling and storage. Plasma is collected by apheresis/plasmapheresis. Administration of plasma is performed at the request of clinicians, according to the strict indications based on the severity of clinical picture, expressed by precisely determined "scoring" of symptoms. The risks transfusion recipients are likely to be exposed to do not differ from those of standard plasma recipients. At the Blood Transfusion Institute of Serbia, the first plasmapheresis from the recovered patient-donor was performed on 11 April 2020 and so far, collection and distribution of CP-COVID-19 have been performed continuously. During the observation period, preliminary results of the effect of CP transfusion, along with other applied therapy, indicate its favourable effect, both worldwide and in Serbia. CP-COVID-19 should be used as early as possible in the course of infection in order to achieve the best outcomes.

Deep mining of early antibody response in COVID-19 patients yields potent neutralisers and reveals high level of convergence

Passive immunisation using monoclonal antibodies will play a vital role in the fight against COVID-19. Until now, the majority of anti-SARS-CoV-2 antibody discovery efforts have relied on screening B cells of patients in the convalescent phase. Here, we describe deep-mining of the antibody repertoires of hospitalised COVID-19 patients using a combination of phage display technology and B cell receptor (BCR) repertoire sequencing to isolate neutralising antibodies and gain insights into the early antibody response. This comprehensive discovery approach has yielded potent neutralising antibodies with distinct mechanisms of action, including the identification of a novel non-ACE2 receptor blocking antibody that is not expected to be affected by any of the major viral variants reported. The study highlighted the presence of potent neutralising antibodies with near germline sequences within both the IgG and IgM pools at early stages of infection. Furthermore, we highlight a highly convergent antibody response with the same sequences occurring both within this study group and also within the responses described in previously published anti-SARS-CoV-2 studies.