What is the relationship between 'MedImmune' and 'AstraZeneca' in the context of the input sentence.
Options: platform, parent organization, original broadcaster, manufacturer

Companies like Pfizer, Sanofi, Merck, AstraZeneca and MedImmune continue to disinfect with a safe SteraMist BIT chemical protecting their operator, facility and the environment, while providing the confidence to the American population that we will produce sterile vaccines.
parent organization