Short summary

A randomised trial to test the effects of BCG vaccine on the specific immune response to seasonal influenza vaccination and other subsequent inactivated vaccines, as well as on the immune system andhealth in general in elderly people > 65 years, with the aim to

a) improve their specific antibody response to vaccination b) improve their general resistance towards infections c) study the effect of BCG on classical lymphocyte-dependent responses, and the induction of innate immune memory.

Rationale

One of the most recognised consequences of aging is a decline in immune function, so-called "immunosenescence". Vaccination is the most effective prophylactic intervention for infectious diseases, but due to immunosenescence, the efficacy of vaccines decreases with increasing age.

It is important to identify novel approaches to strengthen vaccine responses and to improve the general resistance in the elderly. In this respect, the new concept of "trained immunity" offers an attractive target for immunomodulation: epigenetic and functional reprogramming of innate immune cells has been shown to induce broad heterologous protection against infections5.

In the present project, we will explore Bacille Calmette-Guérin (BCG) as a low-cost, low-risk intervention, based on "trained immunity", to increase the immune response to vaccines and improve the general resistance towards infections in elderly.

Description of the cohort

Senior citizens > 65 years of age.

Data and biological material

Blood samples, questionnaire data, data from the patient journal, data from the national registries