Vaccine prophylaxis of Q fever. A follow-up study of the efficacy of Q-Vax (CSL) 1985-1990.
OBJECTIVE
To examine the efficacy of various batches of a formalin-inactivated whole cell Coxiella burnetti vaccine (Henzerling strain, Phase 1 [Q-Vax, CSL]) in the prevention of Q fever among abattoir workers.


METHODS
The study was a retrospective cohort survey of all employees at three South Australian abattoirs to determine the incidence of Q fever among vaccinated and unvaccinated employees during the period 1985 to 1990.


RESULTS
There were two cases of Q fever among 2555 vaccinated employees of the three abattoirs, compared with 55 cases among 1365 unvaccinated employees. The two Q fever cases in vaccinated employees were within a few days of vaccination, before immunity had developed, and represented a coincidence of natural infection and vaccination. Protective efficacy was 100%, even with a batch of Q-Vax containing 20 micrograms/dose rather than the standard dose of 30 micrograms/dose.


CONCLUSIONS
Vaccination was effective for at least five years, although it was uncertain whether this was due to the vaccine per se or to a combination of vaccine immunity reinforced by periodic natural exposure.
Ackland
J R
JR
CSL Ltd, Poplar Road, Parkville, Vic.
Worswick
D A
DA
Marmion
B P
BP
D000003:Abattoirs; D000328:Adult; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D015331:Cohort Studies; D016997:Coxiella burnetii / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D008297:Male; D009784:Occupational Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D011778:Q Fever / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D012189:Retrospective Studies; D012882:Skin Tests; D013021:South Australia / Q000453:epidemiology; D013997:Time Factors; D015164:Vaccines, Inactivated / Q000008:administration & dosage
D001428:Bacterial Vaccines; D015164:Vaccines, Inactivated