Centenarians and extremely old people living with frailty can elicit durable SARS-CoV-2 spike specific IgG antibodies with virus neutralization functions following virus infection as determined by serological study

Abstract

Background The SARS-CoV-2 (Severe Acute Respiratory Syndrome coronavirus 2) has led to more than 165 million COVID-19 cases and >3.4 million deaths worldwide. Epidemiological analysis has revealed that the risk of developing severe COVID-19 increases with age. Despite a disproportionate number of older individuals and long-term care facilities being affected by SARS-CoV-2 and COVID-19, very little is understood about the immune responses and development of humoral immunity in the extremely old person after SARS-CoV-2 infection. Here we conducted a serological study to investigate the development of humoral immunity in centenarians following a SARS-CoV-2 outbreak in a long-term care facility. Methods Extreme aged individuals and centenarians who were residents in a long-term care facility and infected with or exposed to SARS-CoV-2 were investigated between April and June 2020 for the development of antibodies to SARS-CoV-2. Blood samples were collected from positive and bystander individuals 30 and 60 days after original diagnosis of SARS-CoV-2 infection. Plasma was used to quantify IgG, IgA, and IgM isotypes and subsequent subclasses of antibodies specific for SARS-CoV-2 spike protein. The function of anti-spike was then assessed by virus neutralization assays against the native SARS-CoV-2 virus. Findings Fifteen long-term care residents were investigated for SARS-CoV-2 infection. All individuals had a Clinical Frailty scale score ≥5 and were of extreme older age or were centenarians. Six women with a median age of 98.8 years tested positive for SARS-CoV-2. Anti-spike IgG antibody titers were the highest titers observed in our cohort with all IgG positive individuals having virus neutralization ability. Additionally, 5 out of the 6 positive participants had a robust IgA anti-SARS-CoV-2 response. In all 5, antibodies were detected after 60 days from initial diagnosis.

The oldest unvaccinated Covid-19 survivors in South America

“…Such observations support the role of the humoral response against SARS-CoV-2. Our data corroborate a study by Foley and Colleagues, which reported higher anti-spike IgG antibody titers in nonagenarians and centenarians exposed to SARS-CoV-2 in a long-term care home (n = 15) than in younger individuals living in the same environment [27].…”

“…Despite that, worldwide reports of unvaccinated centenarians and supercentenarians (105 years or older) recovered from Covid-19 with mild or moderate symptoms called our attention [25][26][27][28][29]. Understanding why some individuals overcome the disease despite aging, such as the nun Ms. Randon, the oldest person already reported to survive Covid-19 at age 116 [30] is of great interest.…”

Centenarians, Semi and Supercentenarians, COVID-19 and Spanish Flu: a serological assessment to gain insight into the resilience of older centenarians to COVID- 19

“…Further interesting results have been obtained from the study of anti-S neutralising antibodies. A study conducted on centenarians residing in long-term care facilities had already demonstrated that an aged immune system is still capable of producing an antibody response to SARS-CoV-2 infection, and that the antibodies produced had neutralising abilities [27]. Our data con rmed this and additionally showed that the levels of produced antibodies were slightly higher than those produced by seventy-year-old individuals, although the difference was not signi cant.…”

Risk Factors of Severe COVID-19: A Review of Host, Viral and Environmental Factors

“…As an important example, metabolic inflammation [ 1039 ], due to the accumulation of adipose tissue, contributes to the observed inflammatory phenotype in frail individuals [ 1031 ]. Although frail individuals have functional adaptive immune responses after SARS-CoV-2 infection [ 1041 ] and vaccination [ 1042 , 1043 ], faster waning of IgG levels [ 1044 , 1045 ] and immune-senescent memory T cell functions [ 1046 ] indicates that immune memory might be less durable compared to in non-frail individuals.…”