[Skip to Content]
[Skip to Content Landing]
February 6, 1967

Inactivated Mycoplasma Pneumoniae Vaccine: Evaluation in Volunteers

Author Affiliations

From the Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Md. Dr. Smith is now with the Harvard Medical Service, Boston City Hospital.

JAMA. 1967;199(6):353-358. doi:10.1001/jama.1967.03120060051007

The protective effect of an experimental, inactivated Mycoplasma pneumoniae vaccine was evaluated by first injecting volunteers with vaccine and then infecting them with the organism. The vaccine induced the development of growth-inhibiting antibody in ten of 19 volunteers who initially lacked this antibody. Following experimental challenge with M pneumoniae, only one of these ten men who responded to the vaccine became ill, whereas, respiratory tract disease developed in seven of nine men who failed to respond to the vaccine and in ten of 13 volunteers in the control group who lacked the antibody. The most severe clinical illnesses developed in the men who failed to respond to the vaccine. These findings suggest that the vaccine had a protective effect in those men who developed antibody, while those who failed to develop antibody may have been sensitized.