Explorers often take precautions against known diseases.
Vaccines must be formulated for a specific disease. One day after taking or being injected with a vaccine, you gain a bonus equal to 5 + the medicinal’s tier to saving throws against that disease for a number of months equal to the vaccine’s tier. This bonus does not stack with antibiotics.
Starfinder Character Operations Manual © 2019, Paizo Inc.; Authors: Alexander Augunas, Kate Baker, Simone Dietzler, Jennifer Dworschack-Kinter, Leo Glass, Sasha Lindley Hall, Amanda Hamon, Vanessa Hoskins, Jenny Jarzabski, Jason Keeley, Lyz Liddell, Luis Loza, Ron Lundeen, Crystal Malarsky, Robert G. McCreary, Conor J. Owens, Joe Pasini, Owen K.C. Stephens, Jason Tondro, and Landon Winkler.