Immune response to COVID-19 in older adults

Abstract

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the third highly pathogenic coronavirus to emerge in the human population in last two decades. SARS-CoV-2 spread from Wuhan, China, across the globe, causing an unprecedented public healthcare crisis. The virus showed remarkable age dependent pathology, with symptoms resembling common cold in most adults and children while causing more severe respiratory distress and significant mortality in older and frail humans. Even before the SARS-CoV-2 outbreak infectious diseases represented one of the major causes of death of older adults. Loss of immune function and reduced protection from infectious agents with age – immunosenescence - is a result of complex mechanisms affecting production and maintenance of immune cells as well as the initiation, maintenance and termination of properly directed immune responses. Here we briefly discuss the current knowledge on how this process affects age-dependent outcomes of SARS-CoV-2 infection.

One-year follow-up of depression, anxiety, and quality of life of Peruvian patients who survived COVID-19

“…This could be due to older people’s higher prevalence of chronic diseases [ 43 ]. Other factors to consider are their loss of immune function, reduced protection against infectious agents [ 44 ], and poor family support network [ 45 ]. So, elderly COVID-19 survivors will need better access to healthcare for earlier identification and rehabilitation of their impairments.…”

Neutralizing antibodies against SARS-CoV-2 variants of concern elicited by the comirnaty COVID-19 vaccine in nursing home residents

“…Nevertheless, elderly people with frailty and co-morbidities, who are at the highest risk to develop severe forms of COVID-19, were either not included or underrepresented in these studies. Since immunosenescence may be detrimental to the functionality and breadth of vaccine-elicited humoral immune responses 13 , profiling of cross-neutralizing activity against VOCs of sera from fully vaccinated elderly people is of major public health interest. In the current work, we address this issue by comparing the neutralizing capacity of sera from Comirnaty COVID-19-vaccinated nursing home residents with that of sera from younger and seemingly healthy vaccinated individuals and non-vaccinated individuals who recovered from severe COVID-19.…”

Decline of onset-to-diagnosis interval and its impacts on clinical outcome of COVID-19 in China: a nation-wide observational study

“…Age-related Fig. 4 The predictive and real numbers of severe and death cases according to the different cutoff value of ODI changes in host immune activity in response to COVID-19 disease had been identified in previous study which involved alterations in the composition and functional declines of diverse immune cells [33]. During process of disease progression, the effect from ODI was highly likely to be overwhelmed by the predominant role of aging, as the age increased, thus a greater effect was observed from the younger group instead.…”

“…Senescence of the immune system in the elderly led to increased levels of tissue and circulating proinflammatory cytokines in the absence of an immunological threat where accumulating dysfunctional subsets contribute to immune failure [ 30 – 32 ]. Age-related changes in host immune activity in response to COVID-19 disease had been identified in previous study which involved alterations in the composition and functional declines of diverse immune cells [ 33 ]. During process of disease progression, the effect from ODI was highly likely to be overwhelmed by the predominant role of aging, as the age increased, thus a greater effect was observed from the younger group instead.…”