Abstract Background Household transmission of SARS-CoV-2 remains a key driver of community spread , with secondary attack rates in Thai households reaching approximately 50 %. There is limited evidence supporting the efficacy of antiviral post-exposure prophylaxis (PEP) in this context. Methods The phase 2/3, open-label, (1:1) cluster-randomized controlled trial in Thailand , 168 household close contacts from 76 index cases were enrolled to receive either favipiravir-PEP (FPV-PEP) (1600–2000 mg/day for 7 days) or usual care. The efficacy of FPV-PEP was investigated in preventing SARS-CoV-2 infection after contact with index cases. Results The incidence of confirmed SARS-CoV-2 infection was lower in the FPV-PEP group than in the usual care group (7.32 % vs. 14.47 %), although the difference was not statistically significant . A trend toward fewer early positive rapid diagnostic test results on day 3 was observed in the FPV-PEP group. Symptom development was less frequent among FPV...
Protective Efficacy of a #Hemagglutinin-Based #mRNA #Vaccine Against #H5N1 #Influenza Virus Challenge in Lactating Dairy #Cows
Abstract Highly pathogenic avian influenza H5N1 virus has spread to over 1,080 dairy farms across 18 states in the United States, resulting in 41 human infections and posing serious risks to both animal and public health . To address these risks, a hemagglutinin-based mRNA–lipid nanoparticle vaccine was developed , and its safety, immunogenicity, and protective efficacy in high-yielding lactating dairy cows were evaluated. The vaccine was well tolerated, had no adverse effects on health or milk production , and induced strong antibody responses . Two weeks after the second immunization, all the immunized cattle were fully protected against a high-dose H5N1 virus challenge . Notably, two-thirds of the cattle were still completely protected even at the 19th week after the first vaccination , when their serum antibody levels were very low. These data demonstrate that the mRNA vaccine confers robust, lasting protection against H5N1 virus in lactating dairy cows, providing a foundatio...