The first pneumococcal vaccine trials began in South Africa in 1911 and involved miners who were administered a whole-cell vaccine consisting of the known circulating strains of pneumococcal. The results of this first study were improperly recorded and as a result, a second trial of a similarly formulated vaccine was initiated in the summer of 1912. This second vaccine was reported to offer some protection from pneumonia but this protection lasted only about two months. Further, while vaccination appeared to slightly reduce pneumonia rate, it had no impact on pneumonia death rates.
A third trial which involved a similar pneumococcal vaccine was reported by investigators to decrease pneumonia rates by 25 to 50 percent and death rates by 40 to 50 percent. Sir Almroth Knight, the primary researcher involved in the first three clinical trials, however, didn’t document the strains of pneumonia used within the vaccines, making the overall effectiveness of pneumococcal vaccination difficult to determine.
Sir F. Spencer Lister, a protégé of Sir Almroth Knight, expanded on Knight’s earlier work by developing a system to identify and type different strains of pneumococcal. Lister noted the presence of unique pneumococcal strains not found in North America and Europe.
In 1914, Lister developed the first whole-cell pneumococcal vaccine containing three specific strains of S. pneumoniae, now known as serotypes 1, 2, and 5. Lister’s vaccine trials involved the administration of three vaccine doses given one week apart to miners working at three different South African mines. All three mines experienced a decrease in pneumococcal morbidity and mortality in the six to twelve-month period of observation post-vaccination.
By 1918, Lister expanded on his vaccine by adding five additional pneumococcal strains and planned to administer this vaccine to all South African miners. However, by the mid- 1920s, his vaccine was found to be ineffective. By the early 1930s, pneumonia caused by strains 1, 2, 5, and 7, four of the strains targeted by his vaccine, remained low; however, pneumonia rates from strain 3, a strain also found in his vaccine, were noted to be three times higher among those who received the vaccine.
During the First World War, two U.S. military bases began pneumococcal vaccination campaigns and troops were vaccinated with a pneumococcal vaccine containing strains 1, 2, and 3. Vaccination was found to reduce the rates of pneumonia caused by the strains specific to the vaccine but vaccine recipients were studied for a period of only two to three months and the long-term effectiveness of the vaccine was never determined.
Pneumococcal vaccines were also administered in several settings during the 1918 flu pandemic, including military bases, with mixed effectiveness. Vaccines administered during this period also included strains of additional bacteria, such as B. influenza, Staphylococcus aureus, or hemolytic streptococci.
