Primary Omicron infection elicits weak antibody response but robust cellularimmunity in children

The Omicron variant of SARS-CoV-2 is now globally dominant but despite high prevalence little is known regarding the immune response in children. We determined the antibody and cellular immune response following Omicron infection in children aged 6-14 years and related this to prior SARS-CoV-2 infection and vaccination status. Primary Omicron infection elicited a weak antibody response and only 53% of children developed detectable neutralising antibodies. In contrast, children with secondary Omicron infection following prior infection with a pre-Omicron variant developed 24-fold higher antibody titres and neutralisation of Omicron. Vaccination elicited the highest levels of antibody response and was also strongly immunogenic following prior natural infection with Omicron. Cellular responses against Omicron were robust and broadly equivalent in all study groups. These data reveal that primary Omicron infection elicits a weak humoral immune response in children and may presage a clinical profile of recurrent infection as seen with antecedent seasonal coronaviruses. Vaccination may represent the most effective approach to control infection whilst cellular immunity should offer strong clinical protection.

Children develop strong and sustained cross-reactive immune responses against spike protein following SARS-CoV-2 infection

SARS-CoV-2 infection is generally mild or asymptomatic in children but the biological basis for this is unclear. We studied the profile of antibody and cellular immunity in children aged 3-11 years in comparison with adults. Antibody responses against spike and receptor binding domain (RBD) were high in children and seroconversion boosted antibody responses against seasonal Beta-coronaviruses through cross-recognition of the S2 domain. Seroneutralisation assays against alpha, beta and delta SARS-CoV-2 variants demonstrated comparable neutralising activity between children and adults. T cell responses against spike were >2-fold higher in children compared to adults and displayed a TH1 cytokine profile. SARS-CoV-2 spike-specific T cells were also detected in many seronegative children, revealing pre-existing responses that were cross-reactive with seasonal Alpha and Beta-coronaviruses. Importantly, all children retained high antibody titres and cellular responses at 6 months after infection whilst relative antibody waning was seen in adults. Spike-specific responses in children also remained broadly stable beyond 12 months. Children thus distinctly generate robust, cross-reactive and sustained immune responses after SARS-CoV-2 infection with focussed specificity against spike protein. These observations demonstrate novel features of SARS-CoV-2-specific immune responses in children and may provide insight into their relative clinical protection. Furthermore, this information will help to guide the introduction of vaccination regimens in the paediatric population.

Covid-19 lockdown: Ethnic differences in childrens self-reported physical activity and the importance of leaving the home environment. A longitudinal and cross-sectional

BackgroundIn England, the onset of COVID-19 and a rapidly increasing infection rate resulted in a lockdown (March-June 2020) which placed strict restrictions on movement of the public, including children. Using data collected from children living in a multi-ethnic city with high levels of deprivation, this study aimed to: (1) report childrens self-reported physical activity (PA) during the first COVID-19 UK lockdown and identify associated factors; (2) examine changes of childrens self-reported PA prior to and during the first UK lockdown. MethodsThis study is part of the Born in Bradford (BiB) COVID-19 Research Study. PA (amended Youth Activity Profile), sleep, sedentary behaviours, daily frequency/time/destination/activity when leaving the home, were self-reported by 949 children (9-13 years). A sub-sample (n=634) also self-reported PA (Physical Activity Questionnaire for Children) pre-pandemic (2017-February 2020). Univariate analysis assessed differences in PA between sex and ethnicity groups; multivariable logistic regression identified factors associated with childrens PA. Differences in childrens levels of being sufficiently active were examined using the McNemar test examined change in PA prior to and during the lockdown, and multivariable logistic regression to identify factors explaining change. ResultsDuring the pandemic, White British (WB) children were more sufficiently active (34.1%) compared to Pakistani Heritage children (PH) (22.8%) or Other ethnicity children (O) (22.8%). WB children reported leaving the home more frequently and for longer periods than PH and O children. Modifiable variables related to being sufficiently active were frequency, duration, type of activity, and destination away from the home environment. There was a large reduction in children being sufficiently active during the first COVID-19 lockdown (28.9%) compared to pre-pandemic (69.4%). ConclusionsPromoting safe extended periods of PA everyday outdoors is important for all children, in particular for children from ethnic minority groups. Childrens PA during the first COVID-19 UK lockdown has drastically reduced from before. Policy and decision makers, and practitioners should consider the findings in order to begin to understand the impact and consequences that COVID-19 has had upon childrens PA which is a key and vital behaviour for health and development.

Understanding Covid-19 misinformation and vaccine hesitancy in context: Findings from a qualitative study involving citizens in Bradford, UK

BackgroundCovid-19 vaccines can offer a route out of the pandemic, yet initial research suggests that many are unwilling to be vaccinated. A rise in the spread of misinformation is thought to have played a significant role in this vaccine hesitancy. In order to maximise vaccine uptake it is important to understand why misinformation has been able to take hold at this time and why it may pose a more significant problem within certain populations and places. ObjectiveTo understand peoples Covid-19 beliefs, their interactions with health (mis)information during Covid-19 and attitudes towards a Covid-19 vaccine. Design and participantsIn-depth phone interviews were carried out with 20 people from different ethnic groups and areas of Bradford during Autumn 2020. Reflexive thematic analysis was conducted. ResultsParticipants spoke about a wide range of emotive misinformation they had encountered regarding Covid-19, resulting in confusion, distress and mistrust. Vaccine hesitancy could be attributed to three prominent factors: safety concerns, negative stories and personal knowledge. The more confused, distressed and mistrusting participants felt about their social worlds during the pandemic, the less positive they were about a vaccine. ConclusionsCovid-19 vaccine hesitancy needs to be understood in the context of the relationship between the spread of misinformation and associated emotional reactions. Vaccine programmes should provide a focused, localised and empathetic response to counter misinformation. Patient or public contributionA rapid community and stakeholder engagement process was undertaken to identify Covid-19 related priority topics important to both Bradford citizens and local decision makers.

'When will this end? Will it end?' The impact of the March-June 2020 UK Covid-19 lockdown response on mental health: a longitudinal survey of mothers in the Born in Bradford study.

ObjectivesTo explore clinically important increases in depression/anxiety from before to during the first UK Covid-19 lockdown and factors related to this change, with a particular focus on ethnic differences. DesignPre-Covid-19 and lockdown surveys nested within two longitudinal Born in Bradford cohort studies. Participants1,860 mothers with a child aged 0-5 or 9-13, 48% Pakistani heritage Main outcome measuresOdds ratios (OR) for a clinically important increase (5 points or more) in depression (PHQ-8) and anxiety (GAD-7) in unadjusted regression analyses, repeated with exposures of interest separated by ethnicity to look for differences in magnitude of associations, and lived experience of mothers captured in open text questions. ResultsThe number of women reporting clinically important depression/anxiety increased from 11% to 20% [10-13%;18-22%] and 10% to 16% [8-11%; 15-18%]) respectively. Increases in depression/anxiety were associated with: loneliness (OR: 8.37, [5.70-12.27]; 8.50, [5.71-12.65] respectively); financial (6.23, [3.96-9.80]; 6.03, [3.82-9.51]); food (3.33 [2.09-5.28]; 3.46 [2.15-5.58]); and housing insecurity (3.29 [2.36-4.58]; 3.0 [2.11-4.25]); a lack of physical activity (3.13 [2.15-4.56]; 2.55 [1.72-3.78]); and a poor partner relationship (3.6 [2.44-5.43]; 5.1 [3.37-7.62]. The magnitude of associations between key exposures and worsening mental health varied between ethnic groups. Responses to open text questions illustrated a complex inter-play of challenges contributing to mental ill health including: acute health anxieties; the mental load of managing multiple responsibilities; loss of social support and coping strategies; pressures of financial and employment insecurity; and being unable to switch off from the pandemic. ConclusionsMental ill health has worsened for many during the Covid-19 lockdown, particularly in those who are lonely and economically insecure. The magnitude of associations between key exposures and worsening mental health varied between ethnic groups. Mental health problems may have longer term consequences for public health and interventions that address the potential causes are needed. STRENGTHS AND LIMITATIONS OF THIS STUDYO_LIThree key longitudinal studies have highlighted that the Covid-19 pandemic and lockdowns have had a negative impact on mental health, particular in younger adults, women and those from low socio-economic circumstances, but with participants of predominantly White European ethnicity. C_LIO_LIThe Born in Bradford research programme offers a unique opportunity to investigate the impact of Covid-19 lockdown on mental health in a deprived and ethnically diverse population in whom mental ill health is often reported to be more prevalent. C_LIO_LIThis is a longitudinal study containing linked data collected before the Covid-19 pandemic and during the March-June 2020 lockdown which has allowed us to explore change over that time period in a highly ethnically diverse population, the majority of whom live in the most deprived centiles in the UK. C_LIO_LIRespondents in this study were mothers of children aged 0-5 and/or 9-13 which may limit the wider generalisability, though our findings are broadly similar (in prevalence and associations) to those from another longitudinal study that included adult men and women. C_LIO_LIWe are not aware of other studies that have explored longitudinal change in mental health from before to during the Covid-19 lockdown in a similar ethnically diverse and deprived population. C_LI

Heterogeneous distributions of Escherichia coli O157 within naturally infected bovine faecal pats.

Escherichia coli O157 is an important human pathogen for which cattle are considered a reservoir. This paper describes and models the variation in counts of E. coli O157 that exists within individual bovine faecal pats. The presence and concentration of E. coli O157 in faecal samples was determined using a combination of direct spiral plating followed by a more sensitive isolation procedure. The data were modelled using multilevel random effect models, in which the random effects were allowed to be correlated to allow for the fact that pooled and individual samples come from the same pat. Up to a two log difference in the concentration of E. coli O157 was demonstrated in samples from different areas within a faecal pat. Pooling of individual samples from throughout the faecal pat and processing it as one composite sample allows this heterogeneity to be overcome.

Use of a Torque-Range-of-Motion device for objective differentiation of diabetic from normal feet in adults.

BACKGROUND: The ability of the foot and ankle complex to act as an energy absorber is reflected in its viscoelastic properties. The Torque-Range-of-Motion (TROM) device was designed to provide an effective objective assessment of foot and ankle passive mechanical function. The hypothesis of this study was that mechanical parameters derived from passive TROM curves of otherwise normal feet of adults with diabetes would be significantly different from those of adults without diabetes. METHODS: The TROM device is a single-degree-of-freedom hinge transducer system that is manually rotated through plantarflexion and dorsiflexion. The device was rotated manually with the muscles relaxed during a 50-second data acquisition period. A strain gauge provided the torque signal and a precision single-turn potentiometer provided plantarflexion-dorsiflexion angle to a two-channel portable data acquisition system. With the TROM device connected to a computer, input for instantaneous torque and range of motion was acquired and displayed as angle (degrees) versus torque (Newton-meters) on an output screen. The period provided sufficient data to average 16 to 20 cycles of motion. The study included 41 feet in adults without diabetes and 42 age-matched feet in adults with diabetes but no known foot problems. RESULTS: For a probability level of.0001 there were significant differences in hysteresis area (normal: 91.1 +/- 46.9 Nm-deg and diabetic: 161.7 +/- 65.7 Nm-deg) and both dorsiflexion (normal: 0.4 +/- 0.1 Nm/deg and diabetic: 0.9 +/- 0.3 Nm/deg) and plantarflexion stiffness (normal: 0.3 +/- 0.1 Nm/deg and diabetic: 0.7 +/- 0.3 Nm/deg). CONCLUSIONS: The feet of adults with diabetes absorb more energy during cyclic motion (thus must dissipate more energy per cycle) and are stiffer in the terminal regions (where muscle-tendon-ligament properties prevail) than are the feet of adults without diabetes. These results suggest that this passive TROM method may be a sensitive, objective measurement of the viscoelastic properties of the foot and ankle, which may be an early indicator of diabetic patients who are at risk for the development of foot problems.