During the COVID-19 pandemic, researchers at Massachusetts General Hospital (MGH) conducted a Phase III trial to test the effectiveness of the 100-year-old Bacillus Calmette-Guérin (BCG) vaccine on individuals with type 1 diabetes. The BCG vaccine, originally designed to prevent tuberculosis, was found to protect people with type 1 diabetes from severe COVID-19 and other infectious diseases, according to new research conducted at MGH. Two consecutive randomized double-blinded placebo-controlled trials demonstrated that the BCG vaccine offered sustained protection.The findings of this study suggest that BCG vaccination may provide protection against COVID-19 for individuals with type 1 diabetes, who are at a higher risk for severe outcomes from the virus. This is particularly important as mRNA COVID-19 vaccines have been shown to be less effective in this vulnerable population. The lead author of the study, Dr. Denise Faustman, emphasized the potential of BCG vaccination to not only protect against COVID-19, but also other infectious diseases for individuals with type 1 diabetes.The 18-month Phase III trial, which was published in iScience, took place towards the end of the US pandemic when the highly transmissible Omicron variant was spreading. Additionally, a 15-month Phase II trial occurred earlier in the pandemic, and the results were published in Cell Reports Medicine.
Throughout the COVID-19 pandemic, numerous international trials were conducted to determine if giving BCG as a single shot or booster to adults who were previously vaccinated with BCG could protect them from infection and COVID-19. This study added to the extensive global clinical trial database, demonstrating that administering BCG to newborns serves as a foundation for preventing all infectious diseases.The efficacy of COVID-19 booster trials in individuals previously vaccinated with BCG has produced mixed results. Five randomized trials demonstrated effectiveness, while seven trials showed no benefits. The MGH Phase II and Phase III clinical trials differed from previous BCG trials in several key ways. Participants received multiple doses of a potent strain of the BCG vaccine, rather than just one dose. Additionally, the study followed US participants for 36 months, as opposed to the typical weeks or months. It is known that the off-target effects of BCG vaccine in individuals who have not been previously vaccinated can take at least two years to develop.”The full protection of the vaccine may be achieved by giving multiple doses,” Faustman said. Additionally, the clinical trials conducted in the US were unique as the study population had never received a BCG vaccine and was never exposed to TB. Faustman emphasized that trials conducted in countries where participants had previously received BCG vaccine or had previous exposure to tuberculosis may have obscured any benefit from a BCG booster.The MGH trials included 141 people with type 1 diabetes. Of these, 93 individuals in the treatment group received five or six doses of BCG vaccine, while 48 people in the placebo group received sham vaccine. The participants were followed for 36 months to track various COVID-19 genetic variants and exposure to infectious diseases.
In an earlier Phase II trial (January 2020 to April 2021), when the virus was more deadly but less easily spread, the BCG vaccine demonstrated a 92% efficacy rate. This effectiveness was similar to the Pfizer and Moderna COVID-19 vaccines in healthy adults.
Throughout the entire 34-month period of the US COV.During the ID-19 pandemic, researchers found that the BCG vaccine had a 54.3% efficacy. They also discovered that those who received the BCG vaccine had lower rates of viral, bacterial, and fungal infections, as well as COVID-19 itself.
The BCG vaccine provides long-lasting immunity, which is a major advantage compared to vaccines for COVID-19 and other infectious diseases like the flu, which typically only last two or three months. According to Faus, the BCG vaccine has the potential to offer protection against various strains of COVID-19, the flu, respiratory syncytial virus, and other infectious diseases for most of a person’s life.tman.
During the Phase III trial, some participants who had received the BCG treatment also got the Pfizer, Moderna, and Johnson & Johnson COVID-19 vaccines. The researchers found that these vaccines did not provide protection against COVID-19 for people with type 1 diabetes. Faustman stated, “Our study found that the BCG vaccine did not enhance the effectiveness of the COVID-19 vaccine, nor did it have any negative effects on those who received the COVID-19 vaccine.” She also mentioned the possibility of working with the FDA to make the BCG vaccine accessible to type 1 diabetics, who are at a higher risk for the virus as the pandemic continues to develop.Infectious diseases.”
The Iacocca Foundation in Boston, MA provided support for this research.
Other authors who contributed to the study include Willem M. Kühtreiber, Emma R. Hostetter, Grace E. Wolfe, Maya S. Vayshnaw, Rachel Goldstein, Emily R. Bulczynski, Neeshi S. Hullavarad, Joan E. Braley, and Hui Zheng.Â
