Immunosenescence and vaccine failure in the elderly

Abstract

An age-related decline in immune responses in the elderly results in greater susceptibility to infection and reduced responses to vaccination. This decline in immune function affects both innate and adaptive immune systems. A meeting of experts in immunology and gerontology in Paris, France, in April 2008, considered current understanding of immunosenescence and its clinical consequences. Essential features of immunosenescence include: reduced natural killer cell cytotoxicity on a per cell basis; reduced number and function of dendritic cells in blood; decreased pools of naive T and B cells; and increases in the number of memory and effector T and B cells. In particular, an accumulation of late differentiated effector T cells, commonly associated with cytomegalovirus infection, contributes to a decline in the capacity of the adaptive immune system to respond to novel antigens. Consequently, vaccine responsiveness is compromised in the elderly, especially frail patients. Strategies to address the effects of immunosenescence include ensuring that seroprotective antibody levels against preventable infectious diseases are maintained throughout adulthood, and improving diet and exercise to address the effects of frailty. New vaccines are being developed, such as intradermal and high-dose vaccines for influenza, to improve the efficacy of immunization in the elderly. In the future, the development and use of markers of immunosenescence to identify patients who may have impaired responses to vaccination, as well as the use of end-points other than antibody titers to assess vaccine efficacy, may help to reduce morbidity and mortality due to infections in the elderly.

Graft-versus-host disease is the major determinant of humoral responses to the AS03-adjuvanted influenza A/09/H1N1 vaccine in allogeneic hematopoietic stem cell transplant recipients

“…36 Ageing is known to affect humoral responses. [37][38][39] Although increasing age had a profound effect in the control group, we did not observe any impact of age on the patient's capacity to respond to vaccination. This has also been observed by others 22,32 and endorses the hypothesis that allogeneic HSCT may accelerate the physiological ageing of the immune system.…”

Immunogenicity of intramuscular MF59-adjuvanted and intradermal administered influenza enhanced vaccines in subjects aged over 60: A literature review

“…However, despite a high vaccination rate, vaccine efficacy among elderly is lower than among healthy adults. [3][4][5] The weakened immune response observed in elderly people, defined as immunosenescence, 6 is considered to be one of the main reason of the higher risk for influenza-related complications that could lead to hospitalization and death and of the reduced efficacy of influenza vaccination. The reduced immunogenicity and effectiveness of influenza vaccines in subjects with higher risk of influenza-related complications, hospitalizations and deaths, led the innovative drive to search for new strategies to implement the immune response elicited by plain influenza vaccines.…”

B Cells Compartment in Centenarian Offspring and Old People

“…These infections contribute significantly to morbidity in this age-group, and frequently lead to irreversible frailty and dependency. In addition, there is a decline in the protective effect of vaccination in the elderly [1][2][3][4][5][6][7]. Lifelong and chronic antigenic load seem to be the major driving force of immunosenescence, which impacts on human lifespan by reducing the number of virgin antigen-non experienced cells, and, simultaneously, filling the immunological space with expanded clones of memory and effector, antigen-experienced cells [7][8][9].…”