Between 1918 and 1928, horse antiserum was primarily used to treat meningococcal meningitis and public health officials reported that the antiserum was relatively successful in decreasing mortality rates from the disease. However, by 1928, when both meningococcal meningitis disease and death rates rose significantly, treating physicians frequently reported the antiserum to be completely ineffective. In 1929, during an epidemic of meningococcal meningitis, approximately 11,000 cases and 5,208 deaths were reported. While public health officials acknowledged that disease rates had increased significantly during this epidemic, they also reported that meningococcal disease was still very rare. They did, however, express concerns about the high number of fatalities associated with the disease.
In the latter part of the 1930s, researchers began experimenting with sulfonamides as a potential treatment for meningococcal disease. Certain experiments involved the use of a sulfonamide, such as sulfanilamide, or sulfapyridine alone or administered along with horse antiserum. Public health officials reported that the use of horse antiserum in combination with a sulfonamide appeared to be most effective.
The last reported epidemic of meningococcal disease occurred in 1943-1944. In 1943, there were 18,223 reported cases of meningococcal disease, however, by 1950, the disease rate had significantly decreased and only 3,788 cases were reported that year.
