The pertussis incidence during an outbreak in a convent in The Netherlands in 1992 was higher among 75 retired (unvaccinated) nuns (60%) than among 24 staff members (8%) and was higher among 9 nuns with only a convent career (100%) than among 66 nuns who had a career outside of the convent (55%). The pertussis incidence increased with duration of social isolation but not with age.

doi.org/10.1086/510428, hdl.handle.net/1765/36710
Clinical Infectious Diseases
Erasmus MC: University Medical Center Rotterdam

Mertens, P.L.J.M, Borsboom, G.J.J.M, & Richardus, J.H. (2007). A pertussis outbreak associated with social isolation among elderly nuns in a convent. Clinical Infectious Diseases, 44(2), 266–268. doi:10.1086/510428