ABSTRACT
As SARS-CoV-2 continues to spread globally, questions have emerged regarding the strength and durability of immune responses in specific populations. In this study, we evaluated humoral immune responses in 69 children and adolescents with asymptomatic or mild symptomatic SARS-CoV-2 infection. We detected robust IgM, IgG, and IgA antibody responses to a broad array of SARS-CoV-2 antigens at the time of acute infection and 2 and 4 months after acute infection in all participants. Notably, these antibody responses were associated with virus neutralizing activity that was still detectable 4 months after acute infection in 94% of children. Moreover, antibody responses and neutralizing activity in sera from children and adolescents were comparable or superior to those observed in sera from 24 adults with mild symptomatic infection. Taken together, these findings indicate children and adolescents with mild or asymptomatic SARS-CoV-2 infection generate robust and durable humoral immune responses that are likely to protect from reinfection.
ABSTRACT
Objectives@#To determine the prevalence of sarcopenia obesity (SO) in healthy Indian adults and delineate the relative impact of the 3 indices of obesity [body mass index (BMI), waist circumference (WC), fat mass percent (FM%)] with regards to inter-definitional agreement and their relationship with usual gait speed (GS). @*Methods@#Apparently healthy adults (aged ≥ 20 years) with no background history of comorbidities were enrolled from the community by door-to-door survey. Following blood investigations, individuals with biochemical abnormalities were excluded. Enrolled participants underwent dual-energy X-ray absorptiometry (DXA). Sarcopenia was defined according to EWGSOP2 consensus based on indigenous cut-offs obtained from the Sarcopenia-Chandigarh Urban Bone Epidemiological Study (Sarco-CUBES). Obesity was defined based on BMI (≥ 25.0 kg/m2) or WC (> 90 cm in men, > 80 cm in women) or DXA-derived FM% (> 32% in men, > 40% in women). @*Results@#Data of 804 participants were analyzed after exclusion. The mean ± SD for BMI, WC, and FM% were 26.5 ± 2.7 kg/m2, 86.8 ± 9.6, and 34.7 ± 7.3%, respectively. Prevalence of sarcopenia was 3.2%. Based on BMI, WC, and FM%, the prevalence of SO in elderly subjects (≥65 years) was 5.4%, 5.4%, and 6.3%, respectively. Using Cohen’s kappa, inter-definitional agreement between the 3 groups was ‘almost perfect’. FM%, and not BMI/WC, emerged as a significant predictor of GS on multiple linear regression analysis. @*Conclusions@#The prevalence of SO in healthy elderly Indian adults is 5.4%–6.3%. Either BMI/WC/FM% can be used to correctly identify individuals with SO.
ABSTRACT
Objectives@#To determine the prevalence of sarcopenia obesity (SO) in healthy Indian adults and delineate the relative impact of the 3 indices of obesity [body mass index (BMI), waist circumference (WC), fat mass percent (FM%)] with regards to inter-definitional agreement and their relationship with usual gait speed (GS). @*Methods@#Apparently healthy adults (aged ≥ 20 years) with no background history of comorbidities were enrolled from the community by door-to-door survey. Following blood investigations, individuals with biochemical abnormalities were excluded. Enrolled participants underwent dual-energy X-ray absorptiometry (DXA). Sarcopenia was defined according to EWGSOP2 consensus based on indigenous cut-offs obtained from the Sarcopenia-Chandigarh Urban Bone Epidemiological Study (Sarco-CUBES). Obesity was defined based on BMI (≥ 25.0 kg/m2) or WC (> 90 cm in men, > 80 cm in women) or DXA-derived FM% (> 32% in men, > 40% in women). @*Results@#Data of 804 participants were analyzed after exclusion. The mean ± SD for BMI, WC, and FM% were 26.5 ± 2.7 kg/m2, 86.8 ± 9.6, and 34.7 ± 7.3%, respectively. Prevalence of sarcopenia was 3.2%. Based on BMI, WC, and FM%, the prevalence of SO in elderly subjects (≥65 years) was 5.4%, 5.4%, and 6.3%, respectively. Using Cohen’s kappa, inter-definitional agreement between the 3 groups was ‘almost perfect’. FM%, and not BMI/WC, emerged as a significant predictor of GS on multiple linear regression analysis. @*Conclusions@#The prevalence of SO in healthy elderly Indian adults is 5.4%–6.3%. Either BMI/WC/FM% can be used to correctly identify individuals with SO.
