Molecular and serological characterization of clinical isolates of the Influenza virus and evaluation of the cross-immune response to the highly pathogenic avian influenza (HPAI) A (H5N1) 2.3.4.4b virus.

• Grant number: 25/02164-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2025
• End date: August 31, 2028
• Field of knowledge: Biological Sciences - Microbiology
• Principal Investigator: Luiz Mário Ramos Janini
• Grantee: Danielle Dias Conte
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Influenza pandemics, such as those caused by H1N1 and H3N2 strains, highlight the risks associated with the introduction of new zoonotic variants, such as Influenza A (H5N1), which has caused significant outbreaks in birds and mammals, as well as occasional infections in humans. Epidemiological surveillance is crucial for preventing and controlling zoonotic outbreaks, allowing for the identification of changes in circulating viruses and the evaluation of vaccine efficacy. In this context, our project proposes the implementation of continuous surveillance and serological studies on positive samples from the Fleury S.A. laboratory. The methodology includes viral RNA extraction and confirmation by multiplex RT-qPCR, with specific subtyping for H1N1 and H3N2 using RT-qPCR. Viral isolation will be performed in MDCK-SIAT1 cell lines, and H5N1 pseudoviruses or plasmids will be used to assess antibody neutralization. Serological assays, such as hemagglutination inhibition and ELISA-based microneutralization, will be employed to detect antibodies. Given the increasing spread of H5N1 and its pandemic potential, along with the lack of pre-existing immunity in the population, it is essential to intensify surveillance and develop preventive strategies. In this context, our project aims to contribute to strengthening epidemiological surveillance and innovating vaccine strategies to mitigate the impacts of seasonal outbreaks and reduce the risk of future pandemics. (AU)