View clinical trials related to Heterologous Immunity.
Filter by:Background: The virus SARS-CoV-2 has spread rapidly throughout the world. Seniors are at high risk of severe COVID-19 when infected. Bacille Calmette-Guérin (BCG) is a vaccine against tuberculosis, with protective non-specific effects against other infections; significant reductions in morbidity and mortality have been reported, and a plausible immunological mechanism has been identified: "trained innate immunity". The investigators hypothesize that BCG vaccination can reduce the risk of COVID-19 and other infections among senior citizens during the COVID-19 pandemic. Objectives: Primary objective: To reduce senior citizens' risk of acute infection during the COVID-19 pandemic. Secondary objectives: To reduce senior citizens' risk of SARS-CoV-2 infection during the COVID-19 pandemic. To reduce senior citizens' risk of self-reported respiratory illness during the COVID-19 pandemic. Study design: A placebo-controlled randomized trial. Study population: 1900 seniors 65 years of age or above. Intervention: Participants will be randomized 1:1 to intradermal administration of a standard dose of BCG vaccine or placebo (saline). Outcomes: Primary outcome: "Acute infection" identified either by a doctor, antibiotics use, hospitalization, or death due to infection. Secondary outcomes: Verified SARS-CoV-2 infection and self-reported respiratory illness. With an expected incidence of "acute infection" of 20%, the trial can show a 25% risk reduction in the the intervention group versus the placebo group by including a total of 1900 individuals, 950 individuals in each group. Risk for participants and impact: Based on previous experience and randomized controlled trials in adult and elderly individuals, the risks of BCG vaccination are considered low. If BCG can reduce the risk of acute infection in seniors by 25% it has tremendous public health importance, both during the COVID-19 pandemic and overall.
Background: The COVID-19 pandemic challenges the available hospital capacity, and this will be augmented by absenteeism of healthcare workers (HCW). HCW are at high risk, currently HCW constitute 20% of all the COVID-19 cases in Denmark. Strategies to prevent absenteeism of HCW are urgently needed. Bacille Calmette-Guérin (BCG) is a vaccine against tuberculosis, with protective non-specific effects against other infections; significant reductions in morbidity and mortality have been reported, and a plausible immunological mechanism has been identified. We hypothesize that BCG vaccination can reduce HCW absenteeism during the COVID-19 pandemic. Primary objective: To reduce absenteeism among HCW with direct patient contacts during the COVID-19 epidemic. Secondary objective: To reduce the number of HCW that are infected with SARS-CoV-2 during the COVID-19 epidemic and to reduce the number of hospital admissions amongst HCW with direct patient contacts during the COVID-19 epidemic. Study design: A multi-center randomized placebo controlled trial. Study population: 1500 HCW with direct patient contacts; defined as nurses, physicians and other medical staff working at emergency rooms and wards where COVID-infected patients are treated. Intervention: Participants will be randomized 1:1 to intradermal administration of a standard dose of BCG vaccine or placebo (saline). Main study parameters/endpoints: Primary endpoint: Number of days of (unplanned) absenteeism for any reason. Secondary endpoints: Number of days of (unplanned) absenteeism because of documented COVID infection. Cumulative incidence of hospital admissions. Risk for participants and impact: Based on previous experience and randomized controlled trials in adult and elderly individuals, the risks of BCG vaccination are considered low. The objective of this trial is to evaluate the potential beneficial effects of BCG vaccination through a lower work absenteeism rate of HCW and/or a mitigated clinical course of COVID infection.
Background: Investigators at Bandim Health Project (BHP, www.bandim.org) in Guinea-Bissau have shown in several randomized trials that the Bacille-Calmette-Guérin (BCG) vaccine against tuberculosis (TB) is associated with reduced mortality in the first months of life. BCG is a live attenuated vaccine, which means that it consists of active tuberculosis bacteria that are not capable of infecting a human with TB. BCG has been grown and maintained at many different laboratories all over the world using slightly different laboratory techniques. Due to the accumulation of genetic mutations in the different BCG strains, many variants of the vaccine exists today. These have different properties when it comes to immune response, side effects, protection against TB and scar formation. The BCG scar status after vaccination is a good marker for the non-specific effects of the vaccine; among BCG-vaccinated infants, those with a BCG scar have improved survival. The investigators hypothesize that the different types of BCG vary in terms of the strength of the non-specific effects and thus the impact on overall morbidity and mortality. In the trial, the investigators will compare the two most widely used BCG strains in the world, BCG-Russia and BCG-Japan, with respect to their non-specific effects on morbidity and mortality. As an addition, the investigators will study the effect of maternal BCG vaccination on the subsequent effect of BCG-vaccination in the offspring, since there are indications that the maternal BCG scar status primes for a stronger non-specific response in the offspring.