Vaccine effectiveness of CoronaVac against COVID-19 among children in Brazil during the Omicron period.

Although severe COVID-19 in children is rare, they may develop multisystem inflammatory syndrome, long-COVID and downstream effects of COVID-19, including social isolation and disruption of education. Data on the effectiveness of the CoronaVac vaccine is scarce during the Omicron period. In Brazil, children between 6 to 11 years are eligible to receive the CoronaVac vaccine. We conducted a test-negative design to estimate vaccine effectiveness using 197,958 tests from January 21, 2022, to April 15, 2022, during the Omicron dominant period in Brazil among children aged 6 to 11 years. The estimated vaccine effectiveness for symptomatic infection was 39.8% (95% CI 33.7-45.4) at ≥14 days post-second dose. For hospital admission vaccine effectiveness was 59.2% (95% CI 11.3-84.5) at ≥14 days. Two doses of CoronaVac in children during the Omicron period showed low levels of protection against symptomatic infection, and modest levels against severe illness

Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis)

<p>Abstract</p> <p>Background</p> <p>The cotton boll weevil (<it>Anthonomus grandis</it>) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. <it>In vitro </it>directed molecular evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of <it>Bacillus thuringiensis</it>.</p> <p>Results</p> <p>Bioassays carried out with <it>A. grandis </it>larvae revealed that the LC₅₀of the screened mutant Cry8Ka5 toxin was 3.15-fold higher than the wild-type Cry8Ka1 toxin. Homology modelling of Cry8Ka1 and the Cry8Ka5 mutant suggested that both proteins retained the typical three-domain Cry family structure. The mutated residues were located mostly in loops and appeared unlikely to interfere with molecular stability.</p> <p>Conclusions</p> <p>The improved toxicity of the Cry8Ka5 mutant obtained in this study will allow the generation of a transgenic cotton event with improved potential to control <it>A. grandis</it>.</p

Vaccine effectiveness of two-dose BNT162b2 against symptomatic and severe COVID-19 among adolescents in Brazil and Scotland over time: a test-negative case-control study.

BACKGROUND: Little is known about vaccine effectiveness over time among adolescents, especially against the SARS-CoV-2 omicron (B.1.1.529) variant. This study assessed the associations between time since two-dose vaccination with BNT162b2 and the occurrence of symptomatic SARS-CoV-2 infection and severe COVID-19 among adolescents in Brazil and Scotland. METHODS: We did test-negative, case-control studies in adolescents aged 12-17 years with COVID-19-related symptoms in Brazil and Scotland. We linked records of SARS-CoV-2 RT-PCR and antigen tests to national vaccination and clinical records. We excluded tests from individuals who did not have symptoms, were vaccinated before the start of the national vaccination programme, received vaccines other than BNT162b2 or a SARS-CoV-2 booster dose of any kind, or had an interval between their first and second dose of fewer than 21 days. Additionally, we excluded negative SARS-CoV-2 tests recorded within 14 days of a previous negative test, negative tests recorded within 7 days after a positive test, any test done within 90 days after a positive test, and tests with missing sex and location information. Cases (SARS-CoV-2 test-positive adolescents) and controls (test-negative adolescents) were drawn from a sample of individuals in whom tests were collected within 10 days of symptom onset. We estimated the adjusted odds ratio and vaccine effectiveness against symptomatic COVID-19 for both countries and against severe COVID-19 (hospitalisation or death) for Brazil across fortnightly periods. FINDINGS: We analysed 503 776 tests from 2 948 538 adolescents in Brazil between Sept 2, 2021, and April 19, 2022, and 127 168 tests from 404 673 adolescents in Scotland between Aug 6, 2021, and April 19, 2022. Vaccine effectiveness peaked at 14-27 days after the second dose in both countries during both waves, and was significantly lower against symptomatic infection during the omicron-dominant period in Brazil (64·7% [95% CI 63·0-66·3]) and in Scotland (82·6% [80·6-84·5]), than it was in the delta-dominant period (80·7% [95% CI 77·8-83·3] in Brazil and 92·8% [85·7-96·4] in Scotland). Vaccine efficacy started to decline from 27 days after the second dose for both countries, reducing to 5·9% (95% CI 2·2-9·4) in Brazil and 50·6% (42·7-57·4) in Scotland at 98 days or more during the omicron-dominant period. In Brazil, protection against severe disease remained above 80% from 28 days after the second dose and was 82·7% (95% CI 68·8-90·4) at 98 days or more after receiving the second dose. INTERPRETATION: We found waning vaccine protection of BNT162b2 against symptomatic COVID-19 infection among adolescents in Brazil and Scotland from 27 days after the second dose. However, protection against severe COVID-19 outcomes remained high at 98 days or more after the second dose in the omicron-dominant period. Booster doses for adolescents need to be considered. FUNDING: UK Research and Innovation (Medical Research Council), Scottish Government, Health Data Research UK BREATHE Hub, Fiocruz, Fazer o Bem Faz Bem programme, Brazilian National Research Council, and Wellcome Trust. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section

Physical activity attenuates metabolic risk of adolescents with overweight or obesity: the ICAD multi-country study.

BACKGROUND: Although the benefits of physical activity (PA) at an early age are well established, there is no robust evidence of the role of PA as well as its intensities in attenuating the association between weight status and metabolic risk among adolescents. In this investigation, we analyzed the association between weight status, intensities of PA, and metabolic risk among adolescents. METHODS: Data from six cross-sectional studies in the International Children's Accelerometry Database were used (N = 5216 adolescents; boys 14.6 ± 2.1 years and girls 14.7 ± 2.0 years). Weight status was assessed and classified according to body mass index. Fasting glucose, triglycerides, inverse high-density lipoprotein cholesterol, and blood pressure composed the metabolic risk indicator (z-score). PA was measured by accelerometers. The estimated age of peak height velocity was used as a covariate for somatic maturation. RESULTS: We observed that increase in weight status showed a strong positive relationship with metabolic risk. However, adolescents with overweight or obesity in the highest tertile of PA (moderate-to-vigorous and vigorous intensity) showed a similar metabolic risk score as the normal weight groups. Moderate intensity PA seemed related to metabolic risk even within some categories of vigorous PA. CONCLUSIONS: We conclude that PA attenuates the metabolic risk of adolescents with overweight or obesity. Although this attenuation is largely explained by vigorous PA, moderate intensity seems also important for better metabolic profile.Dr. E.M.F. van Sluijs, MRC Epidemiology Unit, University of Cambridge, Cambridge, UK (Sport, Physical activity and Eating behavior: Environmental Determinants in Young people [SPEEDY]). The UK Medical Research Council and the Wellcome Trust (Grant ref: 102215/2/13/2) and the University of Bristol provide core support for ALSPAC

Avaliação de produtos à base de Bacillus thuringiensis no controle da traça-das-crucíferas Evaluation of insecticides based on Bacillus thuringiensis in the control of the diamondback moth

Avaliou-se em dois experimentos a suscetibilidade da traça-das-crucíferas a inseticidas à base de Bacillus thuringiensis em repolho cv. Itiban. O delineamento do primeiro experimento (de julho a setembro/03), em área de plantio comercial em Brazlândia (DF), foi de blocos casualizados, com seis tratamentos e dez repetições; os bioinseticidas utilizados foram B. thuringiensis kurstaki (S1450CO), B. thuringiensis aizawai comercial (Bta) e três produtos formulados com as estirpes S1450BB, S811BB, S845BB de B. thuringiensis pertencentes ao Banco de Bacillus spp. da Embrapa Recursos Genéticos e Biotecnologia. No segundo experimento, realizado no campo experimental da Embrapa (DF), de outubro/03 a janeiro/04, o delineamento foi de blocos casualizados, com seis tratamentos e quatro repetições; os inseticidas utilizados foram os mesmos do primeiro experimento, com a adição de Spinosad, e retirado o tratamento S811BB. Os produtos foram aplicados quando foi atingido o nível de dano de seis furos nas quatro folhas centrais do repolho. O Bta comercial foi o produto mais eficaz no primeiro experimento, tendo sido aplicado cinco vezes e diferiu estaticamente dos demais produtos. Os formulados S845BB e S1450BB não apresentaram diferenças quando comparados ao produto comercial S1450 e foram aplicados seis vezes. O produto S811BB também foi aplicado seis vezes, mas sua eficácia foi inferior aos demais produtos e não diferiu da testemunha. Já no segundo experimento, o S1450 comercial foi aplicado cinco vezes e os demais produtos à base de Bt, seis vezes. Todos os produtos utilizados não diferiram entre si, diferindo apenas no número de aplicações.<br>Two experiments were performed to evaluate the susceptibility of the diamondback moth to insecticides based on Bacillus thuringiensis in cabbage cv. Itiban. The first experiment was carried out from July to September 2003, in a production area in Brazlândia (DF), Brazil. Randomized blocks with six treatments and ten replicates were used. The tested products were: commercial B. thuringiensis kurstaki (S1450), commercial B. thuringiensis aizawai (Bta) and three experimental formulations based on strains S1450BB, S811BB, S845BB of B. thuringiensis from the collection of Bacillus spp. of Embrapa Genetic Resources and Biotecnology. The second experiment was carried out in the experimental area of Embrapa, from October 2003 to January 2004. Randomized blocks with six treatments and four repetitions were used. The tested products were the same as those used in the first experiment with the addition of Spinosad and without S811BB. Products were applied when the level of attack on the plants by the pests reached six holes in the two pairs of central leaves pf the cabbage. Commercial Bta was the most effective product in the first experiment, after five applications and differed from the other products. S845BB and S1450BB were not significantly different when compared to the commercial product S1450, which were applied six times. The product S811BB was also applied six times, but its effectiveness was lower than the other products and was not different to the control. In the second experiment, all products were similar, just differing in the number of applications. Commercial S1450 was applied five times and the other products the base of Bt were applied six times

Type 2 Deiodinase Disruption in Astrocytes Results in Anxiety-Depressive-Like Behavior in Male Mice

Millions of levothyroxine-treated hypothyroid patients complain of impaired cognition despite normal TSH serum levels. This could reflect abnormalities in the type 2 deiodinase (D2)-mediated T(4)-to-T(3) conversion, given their much greater dependence on the D2 pathway for T(3) production. T(3) normally reaches the brain directly from the circulation or is produced locally by D2 in astrocytes. Here we report that mice with astrocyte-specific Dio2 inactivation (Astro-D2KO) have normal serum T(3) but exhibit anxiety-depression-like behavior as found in open field and elevated plus maze studies and when tested for depression using the tail-suspension and the forced-swimming tests. Remarkably, 4 weeks of daily treadmill exercise sessions eliminated this phenotype. Microarray gene expression profiling of the Astro-D2KO hippocampi identified an enrichment of three gene sets related to inflammation and impoverishment of three gene sets related to mitochondrial function and response to oxidative stress. Despite normal neurogenesis, the Astro-D2KO hippocampi exhibited decreased expression of four of six known to be positively regulated genes by T(3), ie, Mbp (∼43%), Mag (∼34%), Hr (∼49%), and Aldh1a1 (∼61%) and increased expression of 3 of 12 genes negatively regulated by T(3), ie, Dgkg (∼17%), Syce2 (∼26%), and Col6a1 (∼3-fold) by quantitative real-time PCR. Notably, in Astro-D2KO animals, there was also a reduction in mRNA levels of genes known to be affected in classical animal models of depression, ie, Bdnf (∼18%), Ntf3 (∼43%), Nmdar (∼26%), and GR (∼20%), which were also normalized by daily exercise sessions. These findings suggest that defects in Dio2 expression in the brain could result in mood and behavioral disorders