Enhancing Biosafety Protocols in Laboratories Conducting Research on the Yellow Fever Virus.

All biological samples are potentially infectious, requiring vaccination and protective equipment for laboratory personnel. The risk classification of pathogenic microorganisms, including the yellow fever virus (YFV), is based on potential risks to individuals, communities, and the environment. Countries have their own classification systems, with Brazil previously following global standards until 1995. YFV is classified as a Risk Group 3 pathogen by the WHO, necessitating handling in Biosafety Level 3 (BSL3) laboratories. Personnel must be vaccinated against YFV at least 10 days prior to contact, as there have been cases of occupationally acquired infections among healthcare and laboratory workers.