The opposite or antonyms of "became infected with" are terms such as "cured," "disinfected," "shielded," "guarded," "protected," and "immunized." These words imply the opposite of getting infected, and instead, these terms suggest the state of being clear of any disease or harmful substances. To cure is to heal or treat an illness, while disinfecting means to clean or eliminate germs or bacteria that can cause an infection. Shielding and guarding refer to protecting from harm, while immunizing means to safeguard from a particular disease by inoculating with a vaccine. These antonyms suggest maintaining good health and taking preventative measures to avoid illnesses.