Lübeck disaster
From 1929 to 1933, 251 infants in Lübeck, northern Germany, were given three doses of the oral BCG vaccine against tuberculosis, which was accidentally contaminated with the bacteria responsible for the disease. 173 later developed signs of the illness and 72 died. Contaminated vaccine 
This vaccine itself was initially blamed, until an inquiry headed by  of the Robert Koch Institute and Ludwig Lange of the Ministry of Health identified contamination as the cause. The event later became known as the Lübeck disaster, or in German, the Lübecker Impfunglück (Lübeck vaccine disaster). Major scientific journals worldwide commented on the disaster and subsequent trials of the medical staff, such as The Lancet and the Journal of the American Medical Association. Legal consequences 
On 6 February 1932, Georg Deycke, the head of the general hospital in Lübeck, was found guilty of negligent homicide and negligent bodily harm, and sentenced to two years in prison. Deycke negligently cultivated the BCG vaccine in a laboratory unsuitable for vaccine production and refrained from animal experiments. Ernst Altstaedt was sentenced to 15 months in prison for negligent homicide and negligent bodily harm as he did not test the vaccine in animal experiments and only insufficiently observed the children. The co-accused chairman of the Lübeck health department, Max Klotz, was acquitted, as was Deycke's laboratory assistant, Anna Schütze. Subsequent developments
Despite the investigation's finding that contamination caused by laboratory error (not the BCG vaccine itself) was the cause of the deaths, the Lübeck disaster diminished public confidence in, and usage of, the BCG vaccine for a time.Elizabeth Whittaker & Surinder K. Tamne, "Bacillus Calmette-Guérin (BCG) Vaccine" in Tuberculosis in Clinical Practice (ed. Inn Min Kon: Springer, 2021), pp. 16-17. After the tragedy, the oral route of administration for BCG vaccine was discontinued. It was replaced by alternate, improved methods of administration for the BCG vaccine: intradermal (ID) (introduced 1927), multiple puncture (1939), and scarification (1947). The First International BCG Congress in Paris, held in 1948, concluded that the BCG vaccine was safe and effective.Kim Connelly Smith, Ian M. Orme & Jeffrey R. Starke, "Tuberculosis vaccines" in Vaccines (6th ed. ), p. 727. Elsevier/Saunders: Eds. Paul A. Offit, Stanley A. Plotkin, Walter A. Orenstein (2013). With the BCG vaccine's safety and effectiveness established, and new methods of administration, confidence in the BCG vaccine was restored, and mass vaccination campaigns resumed globally. Compulsory BCG vaccination of infants was reinstated in East Germany in 1952. References 

Health disasters in Germany
1930s health disasters
Vaccine controversies