Serum HCoV-spike specific antibodies do not protect against subsequent SARS-CoV-2 infection in children and adolescents

SARS-CoV-2 infections in children are generally asymptomatic or mild and rarely progress to severe disease and hospitalization. Why this is so remains unclear. Here we explore the potential for protection due to pre-existing cross-reactive seasonal coronavirus antibodies and compare the rate of antibody decline for nucleocapsid and spike protein in serum and oral fluid against SARS-CoV-2 within the pediatric population. No differences in seasonal coronaviruses antibody concentrations were found at baseline between cases and controls, suggesting no protective effect from pre-existing immunity against seasonal coronaviruses. Antibodies against seasonal betacoronaviruses were boosted in response to SARS-CoV-2 infection. In serum, anti-nucleocapsid antibodies fell below the threshold of positivity more quickly than anti-spike protein antibodies. These findings add to our understanding of protection against infection with SARS-CoV-2 within the pediatric population, which is important when considering pediatric SARS-CoV-2 immunization policies

Impact of meningococcal ACWY conjugate vaccines on pharyngeal carriage in adolescents: evidence for herd protection from the UK MenACWY programme

Objective: Serogroup W and Y invasive meningococcal disease increased globally from 2000 onwards. Responding to a rapid increase in serogroup W clonal complex 11 (W:cc11) invasive meningococcal disease, the UK replaced an adolescent booster dose of meningococcal C conjugate vaccine with quadrivalent MenACWY conjugate vaccine in 2015. By 2018, the vaccine coverage in the eligible school cohorts aged 14 to 19 years was 84%. We assessed the impact of the MenACWY vaccination programme on meningococcal carriage. Methods: An observational study of culture-defined oropharyngeal meningococcal carriage prevalence before and after the start of the MenACWY vaccination programme in UK school students, aged 15 to 19 years, using two cross-sectional studies: 2014 to 2015 “UKMenCar4” and 2018 “Be on the TEAM” (ISRCTN75858406). Results: A total of 10 625 participants preimplementation and 13 434 postimplementation were included. Carriage of genogroups C, W, and Y (combined) decreased from 2.03 to 0.71% (OR 0.34 [95% CI 0.27–0.44], p < 0.001). Carriage of genogroup B meningococci did not change (1.26% vs 1.23% [95% CI 0.77–1.22], p = 0.80) and genogroup C remained rare (n = 7/10 625 vs 17/13 488, p = 0.135). The proportion of serogroup positive isolates (i.e. those expressing capsule) decreased for genogroup W by 53.8% (95% CI –5.0 to 79.8, p = 0.016) and for genogroup Y by 30.1% (95% CI 8.9–46·3, p = 0.0025). Discussion: The UK MenACWY vaccination programme reduced carriage acquisition of genogroup and serogroup Y and W meningococci and sustained low levels of genogroup C carriage. These data support the use of quadrivalent MenACWY conjugate vaccine for indirect (herd) protection

EFFECT OF SEASONS AND MULBERRY VARIETIES ON THE FEED CONVERSION EFFICIENCIES OF DIFFERENT SILKWORM HYBRIDS OF BOMBYX MORI L.

Feed effieincy studies were conducted using three improved silkworm hybrids of Bombyx mori L. and six mulberry varieties. The studies were conducted in winter, summer and monsoon seasons in tropical climate. The results were discussed in the light of productivity. S34 and S13 mulberry varieties appear to be superior over the other mulberry varieties tested presently. The hybrid PMX NB4D2 is efficient compared to other improved varieties studied