Lanzavecchia’s laboratory investigates the mechanisms of antibody-mediated resistance to infectious diseases. They use high-throughput cellular screens to isolate potent and broadly neutralizing antibodies, which can be developed for prophylaxis and treatment of infectious diseases and used as tools for vaccine design. They also address fundamental aspects of the antibody response, such as the role of somatic mutations in affinity maturation and the relationship between infection and autoimmunity. Recently, they discovered in malaria-immune individuals a new mechanism of antibody diversification that involves insertions of templated DNA sequences into immunoglobulin genes.