Metabolite may underlie the sex-specific immune response to COVID-19. A recent study shows that kynurenic acid (KA) may underlie the sex-specific immune response to COVID-19. Researchers analyzed serum metabolites between men and women and found higher KA to kynurenine (K) ratios in male patients whose condition had deteriorated than those who had stabilized. Higher KA levels were also negatively associated with T-cell responses in males suggesting that KA could be a potential target for COVID-19 management in male patients. [Science]

Pfizer vaccine efficacy in real-world conditions is 91% for complete vaccination. A recent prospective cohort study evaluated the effectiveness of the two-dose Pfizer-BioNTech COVID-19 vaccine in real-world conditions. In a sample of 3975 essential workers, first responders, and healthcare personnel, COVID-19 was detected in 204 participants (5%), of which five were vaccinated, 11 were partially vaccinated, and 156 were unvaccinated. Adjusted vaccine effectiveness was estimated to be 91% with complete vaccination and 81% for partial vaccination. Further, vaccination contributed to a reduced viral RNA load, risk of febrile symptoms, and duration of illness among those infected despite vaccination. [NEJM]

IL-6 and corticosteroid use reduces 28-day mortality In COVID-19 patients. A meta-analysis of 27 randomized trials investigating the effect of IL-6 antagonists on 28-day mortality among hospitalized COVID-19 patients found that patients who received IL-6 antagonists had a lower mortality rate than those receiving either usual care or placebo (22% vs. 25%). Additionally, absolute 28-day mortality risk fell to 21% with corticosteroid use compared to 25% for those receiving usual care or placebo. [JAMA Network]

Socioeconomic factors as strong indicators for severe COVID-19 in Paris. In a recent study, researchers in France analyzed key socioeconomic indicators in relation to the risk of hospitalization from COVID-19 in Paris. Income, residence, and occupational status were the most associated indicators, with the third decile of population income being the most at risk (OR=9.10, 95% CI 4.98 to 18.39). Age and population density were less associated with hospitalization risk. Overall, 86% of COVID-19 hospitalized cases were from 45% of the most deprived areas. [BMJ]

Antibiotic and hydroxychloroquine sales increased during the peak of the COVID-19 pandemic in India. A recent study in India used interrupted time series analyses of antibiotic and hydroxychloroquine (HCQ) sales volumes reported between January 2018 and December 2020 to investigate the impact of the COVID-19 pandemic on their consumption. While fewer antibiotics were sold overall in 2020 than 2019, the proportion of non-child appropriate formulation (non-CAF) sales increased from 72.5% to 76.8%, resulting in 216.4 million excess antibiotic doses. HCQ sales also increased by 35.4% between 2019 and 2020, underscoring the urgency of establishing stewardship practices. [PLOS Medicine]

Antimicrobial consumption in humans exceeds that in food-producing animals in the EU/EEA area. The EU/EEA average antimicrobial consumption (AMC) in humans exceeds AMC in food-producing animals, according to a recent report based on data from 2016-2018. This finding indicates that previous steps to reduce AMC in food-producing animals have been effective. Furthermore, complete susceptibility to a standardized panel of antimicrobial classes was negatively associated with AMC, providing evidence that prudent use of all categories of antibiotics should be encouraged. [ECDC/EFSA/EMA Report]

Significant increase in vancomycin‑resistant S. aureus prevalence from 2000 to 2020. According to a systematic review and meta-analysis assessing 62 different studies, Vancomycin‑resistant Staphylococcus aureus (VRSA) prevalence increased by 3.5-fold between 2006 and 2020. VRSA was most prevalent in Africa (16%), with Nigeria having a prevalence of 29%. Considering that prior methicillin-resistant S. Aureus (MRSA) is a risk factor for VRSA, control of MRSA and judicious antimicrobial treatment are necessary for mitigation of MRSA and VRSA. [BMC]

No benefit on all-cause mortality from BCG revaccination in Malawi. A 30-year follow-up from a population-based, double-blind, randomized, placebo-controlled trial in Malawi on the effects of BCG revaccination in preventing tuberculosis and leprosy, revealed no beneficial effects from revaccination on all-cause mortality. Follow-up was available for more than 85% of the individuals that received BCG revaccination (n=23 528) or placebo (n=23 361). There was no difference in all-cause mortality rates between the two groups even when stratified by region, age, or sex. [The Lancet]

Iron deficiency reduces antibody levels against malaria in children. A study led by researchers in Kenya and Uganda assessed the effects of iron deficiency (ID) in children on antibody responses to Plasmodium falciparum malaria. In a sample of 1794 Kenyan and Ugandan children, antibody responses were 2-4 times lower in children with ID than iron-replete children. Lower P. falciparum-specific antibody levels persisted over time in iron-deficient children, underscoring the importance of strategies targeting ID in children. [Clinical Infectious Diseases]

Monoclonal antibody administration in infants could reduce RSV hospitalizations in New Zealand. A modeling study for respiratory syncytial virus (RSV) transmission suggests that maternal vaccination and immunoprophylaxis with monoclonal antibodies (mAb) can lead to a reduction in RSV hospitalization. Seasonal infant mAb was more efficient at disease prevention than the maternal vaccine, reducing infant hospitalization by 30%-43% in children under three months. [Vaccine]

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