Syndromic multiplex serological microarrays to screen for presence of exposure to viruses belonging to the families, most commonly involved in viral emerging diseases (paramyxoviruses, flaviviruses, coronaviruses) will be developed. For each syndrome, antigens from the most common causative viruses will be combined with those of emerging viruses causing illness within the same syndrome. The choice of the microarray format was done to allow serology using small volumes of blood typically available from young children. This approach will be validated in the biobanks of sera from patients with known infection with pathogens that can cross react, and using serum samples from the population part of the biobank described in WP3. This will be done building from expertise in the ANTIGONE project. The population part of the biobank will also be used to do a standardised comparative seroprevalence study of antibodies to emerging viruses currently causing focal outbreaks in Europe.