Table 1 Vaccination of members of the civilian conservation corps, 1934–1937
From: The remarkable history of pneumococcal vaccination: an ongoing challenge
| Â | Vaccinated | Non-vaccinated | Comments |
|---|---|---|---|
1933–4 | 3,126 (0) | 9,000 (8) |  No pneumonia in vaccinated versus 8 cases among unvaccinated |
1934–5 | 14,000 (13) | 12,000 (23) |  Vaccine appeared to be protective, but results difficult to interpret because of heterogeneity amongst the groups |
1934–5 | 14,881 (18) | 18,000 (39) | No type 1 or type 2 pneumonia in the vaccinated group versus 6 of each type among the controls |
1936–7 | 10,740 (13) | 14,494 (24) | Much better follow-up of subjects No pneumonia due to type 1 or 2 pneumococcus in the vaccinated group versus 13 cases in the controls |