RESULTS OF PROPHYLACTIC INOCULATION AGAINST PNEUMOCOCCUS IN 12,519 MEN.

Area of Science:

• Immunology
• Bacteriology
• Preventive Medicine

Background:

• Pneumonia caused by Streptococcus pneumoniae remains a significant public health concern.
• Effective vaccines are crucial for preventing pneumococcal pneumonia.
• Understanding immune response and dosage is key to vaccine efficacy.

Purpose of the Study:

• To evaluate the immune response to pneumococcus (Types I, II, III) vaccination.
• To assess the protective efficacy of pneumococcus vaccination against pneumonia.
• To investigate the relationship between vaccine dosage and immune response.

Main Methods:

• Serum analysis of agglutinins and protective power in 42 vaccinated individuals.
• Dosage variation study: 2.5 billion vs. 13 billion cocci.
• Administration schedule comparison: single, daily, and interval doses.
• Clinical observation of pneumonia incidence in vaccinated and control groups (12,519 vs. ~20,000 men).

Main Results:

• Significant immune response to Pneumococcus Types I and II observed with higher vaccine doses (13 billion).
• Little demonstrable immune response to Type III, despite potential for active immunity.
• No cases of pneumonia (Types I, II, III) in vaccinated individuals receiving two or more doses over 10 weeks.
• Pneumonia incidence was lower in vaccinated troops compared to unvaccinated controls for Types I, II, III, IV, and streptococcus pneumonia.

Conclusions:

• Prophylactic vaccination against Pneumococcus Types I, II, and III is practical and provides protection against pneumonia caused by these types.
• Higher vaccine dosages (e.g., 13 billion) yield a more consistent and greater immune response.
• Dividing total dosage into smaller, frequent inoculations minimizes severe local and general toxic reactions.