View clinical trials related to Non-specific Effects of Vaccines.
Filter by:The trial will be a two-year outcome assessor-blinded RCT at the maternity ward of Hospital Simão Mendes (HNSM) in urban Bissau, Guinea-Bissau to compare vaccination with Bacillus Calmette-Guérin (BCG) Danish strain (AJ Vaccines, Copenhagen 1331 strain) versus BCG-Bulgaria (BB-NCIPD, BCG-SL 222 Sofia strain) 1:1 in 15,000 infants with respect to mortality, morbidity and case-fatality rate during hospital admission. The trial will also examine the association between BCG strains and BCG skin reaction kinetics and characteristics. As a secondary aim, this large study will be used to further evaluate the role of maternal BCG immune priming for overall health, since there are indications that the maternal BCG scar status influences offspring health outcomes.
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.
Since the 1960s, studies have shown that oral polio vaccine (OPV) may have beneficial non-specific effects, reducing morbidity and mortality from other infections than polio. Such beneficial non-specific effect have been observed for other live vaccines, including measles, smallpox and BCG vaccine. For BCG, the vaccine for which the mechanism has been studied the most, the effects appear to be mediated through the innate immune system. The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 has now caused over 7.1 million cases and >400,000 deaths worldwide. As everywhere else, it is anticipated that in Africa the older part of the population will be at risk of severe COVID-19. OPV is widely used in Africa, but for children. Both polio and coronavirus are positive-strand RNA viruses, therefore it is likely that they may induce and be affected by common innate immune mechanisms. In a randomised trial at the Bandim Health Project in Guinea-Bissau, the investigators will assess the effect of providing OPV vs no vaccine to 3400 persons above 50 years of age. The trial will have the power to test the hypothesis that OPV reduces the combined risk of morbidity admission or death (composite outcome) by at least 28% over the subsequent 6 months.
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.