attenuated strains

Attenuated strains are weakened versions of pathogens, like viruses or bacteria, used in vaccines. These strains have been altered so they can't cause serious illness but still stimulate the immune system to recognize and fight the actual pathogen if encountered later. By using these safer, less harmful versions, vaccines help train your body’s defenses without making you sick. This approach has successfully been used in vaccines for diseases such as measles, mumps, and rubella.