Correlates of protection against SARS-CoV-2 Omicron variant and anti-spike antibody responses after a third/booster vaccination or breakthrough infection in the UK general population

Following primary SARS-CoV-2 vaccination, understanding the relative extent of protection against SARS-CoV-2 infection from boosters or from breakthrough infections (i.e. infection in the context of previous vaccination) has important implications for vaccine policy. In this study, we investigated correlates of protection against Omicron BA.4/5 infections and anti-spike IgG antibody trajectories after a third/booster vaccination or breakthrough infection following second vaccination in 154,149 adults [≥]18y from the United Kingdom general population. We found that higher anti-spike IgG antibody levels were associated with increased protection against Omicron BA.4/5 infection and that breakthrough infections were associated with higher levels of protection at any given antibody level than booster vaccinations. Breakthrough infections generated similar antibody levels to third/booster vaccinations, and the subsequent declines in antibody levels were similar to or slightly slower than those after third/booster vaccinations. Taken together our findings show that breakthrough infection provides longer lasting protection against further infections than booster vaccinations. For example, considering antibody levels associated with 67% protection against infection, a third/booster vaccination did not provide long-lasting protection, while a Delta/Omicron BA.1 breakthrough infection could provide 5-10 months of protection against Omicron BA.4/5 reinfection. 50-60% of the vaccinated UK population with a breakthrough infection would still be protected by the end of 2022, compared to <15% of the triple-vaccinated UK population without previous infection. Although there are societal impacts and risks to some individuals associated with ongoing transmission, breakthrough infection could be an efficient immune-boosting mechanism for subgroups of the population, including younger healthy adults, who have low risks of adverse consequences from infection.

Inorganic nanoparticle-based advanced cancer therapies: Promising combination strategies.

Inorganic nanoparticles for drug delivery in cancer treatment offer many potential advantages because they can maximize therapeutic effect through targeting ligands while minimizing off-target side-effects through drug adsorption and infiltration. Although inorganic nanoparticles were introduced as drug carriers, they have emerged as having the capacity for combined therapeutic capabilities, including anticancer effects through cytotoxicity, suppression of oncogenes and cancer cell signaling pathway inhibition. The most promising advanced strategies for cancer therapy are as synergistic platforms for RNA interference (siRNA, miRNA, shRNA) and as synergistic drug delivery agents for the inhibition of cancer cell signaling pathways. The present work summarizes relevant current work, the promise of which is suggested by a projected compound annual growth rate of âˆ¼ 20% for drug delivery alone.

Anticancer therapeutic effect of cerium-based nanoparticles: known and unknown molecular mechanisms.

Cerium-based nanoparticles (CeNPs), particularly cerium oxide (CeO2), have been studied extensively for their antioxidant and prooxidant properties. However, their complete redox and enzyme-mimetic mechanisms of therapeutic action at the molecular level remain elusive, constraining their potential for clinical translation. Although the therapeutic effects of both antioxidant and prooxidant mechanisms generally are attributed to Ce3+ ↔ Ce4+ redox switching mediation, some studies have hinted at the involvement of unknown pathways in therapeutic effects. While redox switching is recognised increasingly as playing a key role in ROS-dependent cancer therapy, ROS-independent cytotoxicity mechanisms, such as Ce4+ dissolution and autophagy, also are emerging as being of importance. Although ROS-mediated prooxidant therapies are the most intensively studied, particularly in the context of cancer, the antioxidant activity deriving from the redox switching, particularly during radiation therapy, also plays an important role in the protection of normal cells during radiation therapy, hence reducing adverse effects. Since cancer cell proliferation results in aberrant behaviour of the tumour microenvironment (TME), then CeNP-based therapies are being used to address a multiplicity of known and unknown factors that aim to normalise the TME and thus prevent this aberrant behaviour. Although it is perceived that the pH plays a key role in the therapeutic performance of cerium-based nanoparticles, this is not conclusive because the relative importances of other factors, particularly Ce dissolution, Ce3+/Ce4+ ratio, cellular H2O2 level, and the role of anions, remain poorly understood. Consequently, the present work explores these multiple chemistry-driven mechanisms, which are both ROS-dependent and ROS-independent, in cancer therapy.

Cardioprotection by Citrus grandis (L.) Peel Ethanolic Extract in Alloxan-Induced Cardiotoxicity in Diabetic Rats.

Diabetic cardiomyopathy (DCM) pathogenesis is multifarious, and there are insufficient therapeutic options to treat DCM. The present research explored the effects of Citrus grandis peel ethanolic extract (CGPE) in alloxan-induced DCM in rats. Diabetes was triggered by intraperitoneal (i.p.) injection of alloxan (150 mg/kg) in Wistar rats (200-250 g). CGPE (100, 200, and 400 mg/kg) or glibenclamide (Glib, 10 mg/kg) were administered orally for 2 weeks. After the treatment schedule, prooxidants (thiobarbituric acid reactive substances), antioxidants (glutathione, catalase, and superoxide dismutase), and inflammatory markers (tumor necrosis factor-α) were determined in cardiac tissues. Biomarkers of cell death, viz., lactate dehydrogenase (LDH), creatine kinase MB (CK-MB) activity, glucose levels, total cholesterol (TC), and high-density lipoproteins (HDL), were assessed in the blood. Rats administered with alloxan showed a consistent increase in blood glucose level (days 7 and 14) that was lowered considerably (p < 0.001) by CGPE or Glib. Alloxan-induced increase in LDH, CK-MB, TC, and decline in HDL was attenuated (p < 0.001) in rats that were treated with CGPE or Glib. Alloxan significantly (p < 0.001) elevated oxidative stress, inflammation, and reduced antioxidants in the cardiac tissue of rats, and these pathogenic abnormalities were ameliorated (p < 0.001) by CGPE. Histopathological studies showed a decrease in morphological disruptions by alloxan in CGPE-treated rats. CGPE (400 mg/kg) significantly ameliorated biochemical parameters in comparison to the lower doses against alloxan cardiotoxicity. Citrus grandis peel extract can be an alternative in the management of DCM.

ROS Modulating Inorganic Nanoparticles: A Novel Cancer Therapeutic Tool.

The term "reactive oxygen species" (ROS) refers to a family of extremely reactive molecules. They are crucial as secondary messengers in both physiological functioning and the development of cancer. Tumors have developed the ability to survive at elevated ROS levels with significantly higher H2O2 levels than normal tissues. Chemodynamic therapy is a novel approach to cancer treatment that generates highly toxic hydroxyl radicals via a Fenton/Fenton-like reaction between metals and peroxides. Inorganic nanoparticles cause cytotoxicity by releasing ROS. Inorganic nanoparticles can alter redox homoeostasis by generating ROS or diminishing scavenging mechanisms. Internalized nanoparticles generate ROS in biological systems independent of the route of internalisation. This method of producing ROS could be employed to kill cancer cells as a therapeutic strategy. ROS also play a role in regulating the development of normal stem cells, as excessive ROS disturb the stem cells' regular biological cycles. ROS treatment has a significant effect on normal cellular function. Mitochondrial ROS are at the centre of metabolic changes and control a variety of other cellular processes, which can lead to medication resistance in cancer patients. As a result, utilising ROS in therapeutic applications can be a double-edged sword that requires better understanding.

The challenge of limited vaccine supplies: impact of prior infection on anti-spike IgG antibody trajectories after a single COVID-19 vaccination

Given high SARS-CoV-2 incidence, coupled with slow and inequitable vaccine roll-out, there is an urgent need for evidence to underpin optimum vaccine deployment, aiming to maximise global population immunity at speed. We evaluate whether a single vaccination in previously infected individuals generates similar initial and subsequent antibody responses to two vaccinations in those without prior infection. We compared anti-spike IgG antibody responses after a single dose of ChAdOx1, BNT162b2, or mRNA-1273 SARS-CoV-2 vaccines in the COVID-19 Infection Survey in the UK general population. In 100,849 adults who received at least one vaccination, 13,404 (13.3%) had serological and/or PCR evidence of prior infection. Prior infection significantly boosted antibody responses for all three vaccines, producing a higher peak level and longer half-life, and a response comparable to those without prior infection receiving two vaccinations. In those with prior infection, median time above the positivity threshold was estimated to last for >1 year after the first dose. Single-dose vaccination targeted to those previously infected may provide protection in populations with high rates of previous infection faced with limited vaccine supply, as an interim measure while vaccine campaigns are scaled up.

Therapeutic efficacy of rifaximin loaded tamarind gum polysaccharide nanoparticles in TNBS induced IBD model Wistar rats.

BACKGROUND: Rifaximin is a non-systemic antibiotic used in the treatment of inflammatory bowel disease (IBD). Antibiotics are demonstrating a significant role in the treatment of IBD by altering the dysbiotic colonic microbiota and decreases the immunogenic and inflammatory response in the patient population. Mucoadhesive colon targeted nanoparticles provide the site-specific delivery and extended stay in the colon. Since the bacteria occupy the lumen, spread over the surface of epithelial cells, and adhere to the mucosa, delivering the rifaximin as a nanoparticles with the mucoadhesive polymer enhances the therapeutic efficacy in IBD. The objective was to fabricate and characterize the rifaximin loaded tamarind gum nanoparticles and study the therapeutic efficacy in the TNBS-induced IBD model rats. MATERIALS AND METHODS: The experimentation includes fabrication and characterization of drug excipient compatibility by FTIR. The fabricated nanoparticles were characterized for the hydrodynamic size and zeta potential by photon correlation spectroscopy and also analyzed by TEM. Selected best formulation was subjected to the therapeutic efficacy study in TNBS-induced IBD rats, and the macroscopic, microscopic and biochemical parameters were reported. RESULTS: The study demonstrated that the formulation TGN1 is best formulation in terms of nanoparticle characterization and hydrodynamic size which showed the hydrodynamic size of 171.4 nm and the zeta potential of -26.44 mV and other parameters such as TEM and drug release studies were also reported. CONCLUSIONS: The therapeutic efficacy study revealed that TGN1 is efficiently reduced the IBD inflammatory conditions as compared to the TNBS control group and reference drug mesalamine group.

Impact of Delta on viral burden and vaccine effectiveness against new SARS-CoV-2 infections in the UK

The effectiveness of BNT162b2, ChAdOx1, and mRNA-1273 vaccines against new SARS-CoV-2 infections requires continuous re-evaluation, given the increasingly dominant Delta variant. We investigated the effectiveness of the vaccines in a large community-based survey of randomly selected households across the UK. We found that the effectiveness of BNT162b2 and ChAd0x1 against any infections (new PCR positives) and infections with symptoms or high viral burden is reduced with the Delta variant. A single dose of the mRNA-1273 vaccine had similar or greater effectiveness compared to a single dose of BNT162b2 or ChAdOx1. Effectiveness of two doses remains at least as great as protection afforded by prior natural infection. The dynamics of immunity following second doses differed significantly between BNT162b2 and ChAdOx1, with greater initial effectiveness against new PCR-positives but faster declines in protection against high viral burden and symptomatic infection with BNT162b2. There was no evidence that effectiveness varied by dosing interval, but protection was higher among those vaccinated following a prior infection and younger adults. With Delta, infections occurring following two vaccinations had similar peak viral burden to those in unvaccinated individuals. SARS-CoV-2 vaccination still reduces new infections, but effectiveness and attenuation of peak viral burden are reduced with Delta.

Effect of COVID-19 on inequalities in premature mortality in England: an analysis of excess mortality by deprivation and ethnicity

ObjectivesTo examine the impact of the Covid-19 pandemic on inequalities in premature mortality in England by deprivation and ethnicity. DesignA statistical model to estimate increased mortality in population sub-groups during the Covid-19 pandemic by comparing observed with expected mortality in each group based on trends over the previous five years. SettingInformation on deaths registered in England since 2015 was used, including age, sex, area of residence, and cause of death. Ethnicity was obtained from Hospital Episode Statistics (HES) records linked to death registration data. ParticipantsPopulation study of England, including all 569,824 deaths from all causes registered between 21 March 2020 and 26 February 2021. Main outcome measuresExcess mortality in each sub-group over and above the number expected based on trends in mortality in that group over the previous five years. ResultsThe gradient in excess mortality by deprivation was greater in the under 75s (most deprived had 1.25 times as many deaths as expected, least deprived 1.14) than in all ages (most deprived had 1.24 times as many deaths as expected, least deprived 1.20). Among the Black and Asian groups, all deprivation quintiles had significantly larger excesses than the most deprived White group and there were no clear gradients across quintiles. Among the White group, only the most deprived had more excess deaths than deaths directly involving Covid-19. Among the Black group all deprivation quintiles experienced more excess deaths than deaths directly involving Covid-19. ConclusionThe Covid-19 pandemic has widened inequalities in premature mortality by deprivation. Among those under 75, the direct and indirect effects of the pandemic on deaths have disproportionately impacted ethnic minority groups irrespective of deprivation, and the most deprived White group. Statistics limited to deaths directly involving Covid-19 understate the pandemics impact on inequalities by deprivation and ethnic group at younger ages. Key Messages What is already known on this topicO_LIEstimates of excess mortality for all ages combined for the period March 2020 to February 2021 show a small difference in the relative impact of Covid-19 on excess mortality between the most deprived and the least deprived C_LIO_LIThroughout the pandemic estimates of excess mortality have been greater for ethnic minority groups compared with the white group. C_LI What this study addsO_LIAmong the under 75s the gradient of excess mortality across the deprivation spectrum indicates a stark increase in already established inequalities in premature mortality C_LIO_LIIndependent of deprivation, excess mortality in Black and Asian ethnic groups is much higher than that of the white group, indicating that ethnicity is a determinant of excess mortality, regardless of level of area-based deprivation. C_LI

Impact of vaccination on SARS-CoV-2 cases in the community: a population-based study using the UK COVID-19 Infection Survey

ObjectivesTo assess the effectiveness of COVID-19 vaccination in preventing SARS-CoV-2 infection in the community. DesignProspective cohort study. SettingThe UK population-representative longitudinal COVID-19 Infection Survey. Participants373,402 participants aged [≥]16 years contributing 1,610,562 RT-PCR results from nose and throat swabs between 1 December 2020 and 3 April 2021. Main outcome measuresNew RT-PCR-positive episodes for SARS-CoV-2 overall, by self-reported symptoms, by cycle threshold (Ct) value (<30 versus [≥]30), and by gene positivity (compatible with the B.1.1.7 variant versus not). ResultsOdds of new SARS-CoV-2 infection were reduced 65% (95% CI 60 to 70%; P<0.001) in those [≥]21 days since first vaccination with no second dose versus unvaccinated individuals without evidence of prior infection (RT-PCR or antibody). In those vaccinated, the largest reduction in odds was seen post second dose (70%, 95% CI 62 to 77%; P<0.001).There was no evidence that these benefits varied between Oxford-AstraZeneca and Pfizer-BioNTech vaccines (P>0.9).There was no evidence of a difference in odds of new SARS-CoV-2 infection for individuals having received two vaccine doses and with evidence of prior infection but not vaccinated (P=0.89). Vaccination had a greater impact on reducing SARS-CoV-2 infections with evidence of high viral shedding Ct<30 (88% reduction after two doses; 95% CI 80 to 93%; P<0.001) and with self-reported symptoms (90% reduction after two doses; 95% CI 82 to 94%; P<0.001); effects were similar for different gene positivity patterns. ConclusionVaccination with a single dose of Oxford-AstraZeneca or Pfizer-BioNTech vaccines, or two doses of Pfizer-BioNTech, significantly reduced new SARS-CoV-2 infections in this large community surveillance study. Greater reductions in symptomatic infections and/or infections with a higher viral burden are reflected in reduced rates of hospitalisations/deaths, but highlight the potential for limited ongoing transmission from asymptomatic infections in vaccinated individuals. RegistrationThe study is registered with the ISRCTN Registry, ISRCTN21086382.

Reducing Ethnic and Geographic Inequities to Optimise New Zealand Stroke Care (REGIONS Care): Protocol for a Nationwide Observational Study.

BACKGROUND: Stroke systems of care differ between larger urban and smaller rural settings and it is unclear to what extent this may impact on patient outcomes. Ethnicity influences stroke risk factors and care delivery as well as patient outcomes in nonstroke settings. Little is known about the impact of ethnicity on poststroke care, especially in Maori and Pacific populations. OBJECTIVE: Our goal is to describe the protocol for the Reducing Ethnic and Geographic Inequities to Optimise New Zealand Stroke Care (REGIONS Care) study. METHODS: This large, nationwide observational study assesses the impact of rurality and ethnicity on best practice stroke care access and outcomes involving all 28 New Zealand hospitals caring for stroke patients, by capturing every stroke patient admitted to hospital during the 2017-2018 study period. In addition, it explores current access barriers through consumer focus groups and consumer, carer, clinician, manager, and policy-maker surveys. It also assesses the economic impact of care provided at different types of hospitals and to patients of different ethnicities and explores the cost-efficacy of individual interventions and care bundles. Finally, it compares manual data collection to routine health administrative data and explores the feasibility of developing outcome models using only administrative data and the cost-efficacy of using additional manually collected registry data. Regarding sample size estimates, in Part 1, Study A, 2400 participants are needed to identify a 10% difference between up to four geographic subgroups at 90% power with an α value of .05 and 10% to 20% loss to follow-up. In Part 1, Study B, a sample of 7645 participants was expected to include an estimated 850 Maori and 419 Pacific patients and to provide over 90% and over 80% power, respectively. Regarding Part 2, 50% of the patient or carer surveys, 40 provider surveys, and 10 focus groups were needed to achieve saturation of themes. The main outcome is the modified Rankin Scale (mRS) score at 3 months. Secondary outcomes include mRS scores; EQ-5D-3L (5-dimension, 3-level EuroQol questionnaire) scores; stroke recurrence; vascular events; death; readmission at 3, 6, and 12 months; cost of care; and themes around access barriers. RESULTS: The study is underway, with national and institutional ethics approvals in place. A total of 2379 patients have been recruited for Part 1, Study A; 6837 patients have been recruited for Part 1, Study B; 10 focus groups have been conducted and 70 surveys have been completed in Part 2. Data collection has essentially been completed, including follow-up assessment; however, primary and secondary analyses, data linkage, data validation, and health economics analysis are still underway. CONCLUSIONS: The methods of this study may provide the basis for future epidemiological studies that will guide care improvements in other countries and populations. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/25374.

Increased infections, but not viral burden, with a new SARS-CoV-2 variant

BackgroundA new variant of SARS-CoV-2, B.1.1.7/VOC202012/01, was identified in the UK in December-2020. Direct estimates of its potential to enhance transmission are limited. MethodsNose and throat swabs from 28-September-2020 to 2-January-2021 in the UKs nationally representative surveillance study were tested by RT-PCR for three genes (N, S and ORF1ab). Those positive only on ORF1ab+N, S-gene target failures (SGTF), are compatible with B.1.1.7/VOC202012/01. We investigated cycle threshold (Ct) values (a proxy for viral load), percentage of positives, population positivity and growth rates in SGTF vs non-SGTF positives. Results15,166(0.98%) of 1,553,687 swabs were PCR-positive, 8,545(56%) with three genes detected and 3,531(23%) SGTF. SGTF comprised an increasing, and triple-gene positives a decreasing, percentage of infections from late-November in most UK regions/countries, e.g. from 15% to 38% to 81% over 1.5 months in London. SGTF Ct values correspondingly declined substantially to similar levels to triple-gene positives. Population-level SGTF positivity remained low (<0.25%) in all regions/countries until late-November, when marked increases with and without self-reported symptoms occurred in southern England (to 1.5-3%), despite stable rates of non-SGTF cases. SGTF positivity rates increased on average 6% more rapidly than rates of non-SGTF positives (95% CI 4-9%) supporting addition rather than replacement with B.1.1.7/VOC202012/01. Excess growth rates for SGTF vs non-SGTF positives were similar in those up to high school age (5% (1-8%)) and older individuals (6% (4-9%)). ConclusionsDirect population-representative estimates show that the B.1.1.7/VOC202012/01 SARS-CoV-2 variant leads to higher infection rates, but does not seem particularly adapted to any age group.

Community prevalence of SARS-CoV-2 in England: Results from the ONS Coronavirus Infection Survey Pilot

ObjectiveTo estimate the percentage of individuals infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) over time in the community in England and to quantify risk factors. DesignRepeated cross-sectional surveys of population-representative households with longitudinal follow-up if consent given. SettingEngland Participants34,992 Individuals aged 2 years and over from 16,722 private residential households. Data were collected in a pilot phase of the survey between 26 April and 28 June 2020. Main outcome measuresPercentage of individuals in the community testing positive for SARS-CoV-2 RNA using throat and nose swabs. Individuals were asked about any symptoms and potential risk factors. ResultsThe percentage of people in private-residential households testing positive for SARS-CoV-2 reduced from 0.32% (95% credible interval (CrI) 0.19% to 0.52%) on 26 April to 0.08% (95% CrI 0.05% to 0.12%) on 28 June, although the prevalence stabilised near the end of the pilot. Factors associated with an increased risk of testing positive included having a job with direct patient contact (relative exposure (RE) 4.06, 95% CrI 2.42 to 6.77)), working outside the home (RE 2.49, 95% CrI 1.39 to 4.45), and having had contact with a hospital (RE 2.20, 95% CrI 1.09 to 4.16 for having been to a hospital individually and RE 1.95, 95% CrI 0.81 to 4.09 for a household member having been to a hospital). In 133 visits where individuals tested positive, 82 (61%, 95% CrI 53% to 69%) reported no symptoms, stably over time. ConclusionThe percentage of SARS-CoV-2 positive individuals declined between 26 April and 28 June 2020. Positive tests commonly occurred without symptoms being reported. Working outside your home was an important risk factor, indicating that continued monitoring for SARS-CoV-2 in the community will be essential for early detection of increases in infections following return to work and other relaxations of control measures. What is already known on this topic- Unprecedented control measures, such as national lockdowns, have been widely implemented to contain the spread of SARS-CoV-2. - Previous mass surveillance has been based on data sources such as hospital admission, deaths or self-reported symptoms that do not measure community prevalence of virus directly. - Decisions regarding the continued need for social distancing measures in the overall population, specific subgroups and geographic areas heavily rely on accurate and up-to-date information about the number of people and risk factors for testing positive. What this study adds- The percentage of individuals from the general community in England testing positive for SARS-CoV-2 clearly declined between 26 April and 28 June 2020 from around one in three 300 to around one in a thousand. - Risk factors for testing positive included having a job with direct patient contact, having had (indirect) contact with a hospital in the past 2 weeks, and working outside your home. - Positive tests commonly occurred without symptoms being reported and the percentage of individuals with a positive test that reported no symptoms was stable over time.

Nanoemulsion for Migraine Prophylaxis Nasal Drug Delivery: Preparation, Characterization and in vitro Evaluation.

BACKGROUND: Flunarizine dihydrochloride is used as a prophylaxis to migraine. Flunarizine dihydrochloride nanoemulsion was fabricated in this research work. Since, it is a low soluble high permeable drug, work was designed to enhance the solubility and the same can be administered as nasal drug delivery for faster onset of action and therapeutic effect. OBJECTIVE: To fabricate a nanoemulsion of flunarizine dihydrochloride by using surfactant and co-surfactants. METHODS: The experimental work involved compatibility studies by using FTIR, crystallinity study by XRD. The prepared nanoemulsion was studied by photon correlation spectroscopy by master sizer 2000 for the particle size analysis and characterized for D10, D50 and D90 MPS, span and uniformity. Further studies were conducted by Laser light scattering technique by delsa nano common and TEM. RESULTS: The study demonstrated that the formulations (FNE 1 -FNE 5) demonstrated the MPS of 14, 22.7, 326.7, 14.3 and 40.73 respectively. The formulae FNE1 and FNE5 demonstrated the MPS of 214.6±179.9 and 2118.6 ±1503.6 with the diameter of 127.8 and 1307, respectively. The zeta potential of FNE1 was -3.84 mV and other parameters such as TEM and drug release studies were also reported. CONCLUSION: The nanoemulsion of Flunarizine dihydrochloride was prepared successfully by using cremophor and labrafil which was better than the existed formula prepared by tween 80. The optimised formula demonstrated lower droplet size, satisfactory zeta potential, and high drug loading reproducible drug release profile.