In a warmer, more humid, and more crowded world, people will also come into contact with pathogens more frequently. Scientists are working on ways to respond more quickly to pandemics. Vaccination causes the body to create antibodies against the invader, but complete immunity takes several weeks. Even for an exotic and unfamiliar virus, a quicker and more foolproof method could be to give people lab-produced antibodies. People would take the antibodies for instantaneous protection if a pandemic broke out, says Antonio Lanzavecchia, an immunologist at the Institute for Research in Biomedicine in Switzerland. As long as scientists know which antibody is needed, cranking out a large supply is easy. Lanzavecchia has already found and produced such an antibody that protects mice and ferrets against many influenza A strains, and he is currently planning human clinical trials. He says a drug would take at least five years to become available to the public. And like other medical advances, it could be useful even if people keep climate change in check.