SARS-CoV-2 Omicron-B.1.1.529 leads to widespread escape from neutralizing antibody responses

On 24th November 2021, the sequence of a new SARS-CoV-2 viral isolate Omicron-B.1.1.529 was announced, containing far more mutations in Spike (S) than previously reported variants. Neutralization titers of Omicron by sera from vaccinees and convalescent subjects infected with early pandemic Alpha, Beta, Gamma, or Delta are substantially reduced, or the sera failed to neutralize. Titers against Omicron are boosted by third vaccine doses and are high in both vaccinated individuals and those infected by Delta. Mutations in Omicron knock out or substantially reduce neutralization by most of the large panel of potent monoclonal antibodies and antibodies under commercial development. Omicron S has structural changes from earlier viruses and uses mutations that confer tight binding to ACE2 to unleash evolution driven by immune escape. This leads to a large number of mutations in the ACE2 binding site and rebalances receptor affinity to that of earlier pandemic viruses

Identification of Primary Drug Resistance to Rifampin in Mycobacterium leprae Strains from Leprosy Patients in Amazonas State, Brazil

The aim of this study was to identify polymorphisms in the folp1, gyrA, and rpoB genes in leprosy patients treated in Amazonas State, Brazil. Among 197 slit-skin smear samples from untreated or relapsed patients, we found three cases of primary resistance to rifampin and one confirmed case of multidrug resistance

Co-infection of Dengue virus by serotypes 3 and 4 in patients from Amazonas, Brazil

The natural co-infection with dengue virus can occur in highly endemic areas where different serotypes have been observed for many years. We report here four cases of DENV-3/DENV-4 co-infection detected by serological and molecular tests among 674 patients with acute undifferentiated fever from the tropical medicine reference center of Manaus City, Brazil, between 2005 and 2010. Analysis of the sequences obtained indicated the presence of genotype 3 and 1 for DENV-3 and DENV-4 respectively

Genomic and epidemiological surveillance of Zika virus in the Amazon region

Zika virus (ZIKV) has caused an explosive epidemic linked to severe clinical outcomes in the Americas. Until June 2018, 4,929 ZIKV suspected infections and 46 congenital syndrome cases were reported in Manaus city, Amazonas State, Brazil. Although Manaus is a key demographic hub in the Amazon region, little is known about the ZIKV epidemic there, both in terms of transmission and viral genetic diversity. Using portable virus genome sequencing we generated 59 ZIKV genomes in Manaus. Phylogenetic analyses indicated multiple introductions of ZIKV from northeast Brazil to Manaus. Spatial genomic analysis of virus movement among 6 areas in Manaus suggested that populous northern neighborhoods acted as sources of virus transmission to other neighborhoods. Our study revealed how the ZIKV epidemic was ignited and maintained within the largest urban metropolis in the Amazon. Those results might contribute to improve public health response to outbreaks in Brazil