Comparison of SARS-CoV-2 antibody profiles in the elderly and young

recently Science report In the study, researchers found a dual response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with the Pfizer-BioNTech BNT162b2 messenger ribonucleic acid (mRNA) vaccine in very elderly individuals over the age of 90. The antibody titer after vaccination is compared and evaluated. Population between the ages of 23 and 69.

Previous studies have reported a gradual decline and remodeling of the immune system’s response with aging, and the efficacy of the SARS-CoV-2 vaccine changes with age. In particular, older patients are at increased risk of severe coronavirus disease (COVID-19) in 2019. However, serological data on elderly people over 90 years of age after COVID-19 vaccination are limited.

study: 6-month SARS-CoV-2 serology in a cohort of mRNA-vaccinated subjects over 90 years of age.. Image Credit: Stock-Asso / Shutterstock.com

About research

In a current cross-sectional study, researchers evaluated the anti-SARS-CoV-2 humoral immune response in very elderly individuals and obtained the results from a young population between the ages of 23 and 69 after BNT162b2 vaccination in Italy. Compared with the data obtained.

Data were obtained from post-vaccination serological reports of anti-SARS-CoV-2 antibodies in the very elderly and young / general population. These samples were collected as part of the COVIDIAG-NOSTIX project from December 2020 to September 2021.

The young population consisted of health care workers employed in the COVID-19 vaccination campaign in Italy. By comparison, the very elderly population consisted of individuals who received home care support from the Operatori Sanitari Association (OSA) Cooperative for medication and rehabilitation purposes.

Serum was obtained from study participants after 6 months of double mRNA BNT162b2 vaccination. The elderly cohort also completed rapid antibody testing during serum sample collection.

Antibodies to the SARS-CoV-2 peplomer (S) protein receptor binding domain (RBD) and nucleocapsid (N) proteins were evaluated using the electrochemiluminescence immunoassay (ECLIA). Rapid antibody testing included a chemiluminescence (CLIA) assay to detect anti-SARS-CoV-2 S immunoglobulin G (IgG).

Rapid antibody testing based on chromatographic assays was also performed to detect anti-S and anti-NIgM and IgG titers. These tests were completed in 10 minutes, and researchers were able to get immediate results for the very elderly.

Survey results

The very old and young population included 97 and 1,114, respectively. The follow-up period and the proportion of individuals and women with an anti-SARS-CoV-2 N seroprevalence of 8-9% were similar among study participants.

Significant differences in anti-SARS-CoV-2S titers were observed between anti-N seropositive and seronegative participants, with medians of 2,500 U / mL and 587 U / mL, respectively, in the younger population. Corresponding values ​​of 2,500 U / mL and 65 U / mL were reported in the very elderly population, respectively.

Considering only seronegative individuals, there was a significant reduction in both groups, with a reduced humoral response in the very elderly. Gender-specific immunity differences were found only in the younger population.

Over 60% of the younger group of seropositive cases were women. By comparison, in the very elderly group, which included only 7 women, none of the male participants showed seropositive. Therefore, comparisons can only be made between women. No significant difference was observed between young and very old participants for this purpose.

Anti-N seropositive and age are the most important factors in determining anti-SARS-CoV-2 S antibody levels, followed by gender, which has a significant but limited effect on overall results. I did. The same differences were observed between anti-SARS-CoV-2 N seropositive and seronegative individuals among very elderly participants, with a median of 2,080 U / s between anti-N seropositive and seronegative individuals, respectively. mL and 42.5 UA / mL were reported.

Rapid antibody testing was able to detect anti-S IgG antibodies, with Roche Elecsys testing showing serum antibody titers above 197 UA / mL and specificity and sensitivity of 83% and 100%, respectively. In addition, there was a correlation between good serological test reports and positive immune levels on rapid antibody testing, with median values ​​of 3,263 UA / mL, 899 UA / mL, and 809 UA / mL, respectively, strong. There were positive, positive, and slightly positive reports.

Anti-S Antibody titer Individuals with a negative serologic response to anti-N (according to Roche Elecsys SARS-CoV-2-S). The blue box (M) indicates a male subject and the red box (F) indicates a female subject. *** p <0.001 vs. corresponding colors in the cohort aged 23-69. ### p <0.001 vs women in the same cohort.

Conclusion

The results of the study show that very old individuals induced detectable anti-SARS-CoV-2S titers after the second BNT162b2 vaccination. This reaction was primarily observed in anti-N serum-positive individuals who had a previous history of COVID-19. In this group, the anti-N titer was comparable to that of the young cohort.

Similarly, older people who were negative for anti-N serum responses had fewer anti-S antibodies compared to the younger cohort. Therefore, SARS-CoV-2 specific antibody responses varied based on anti-N serum status, individual age, and gender in the very elderly.

This study was the first of its kind to provide post-vaccination data for individuals over 90 years of age. These findings may affect COVID-19 vaccination campaign organizations, including booster dose administration and prioritization of vaccine recipients.

In addition, anti-SARS-CoV-2 antibody titers require additional vaccination, especially among elderly individuals whose immune response to infection may not be as efficient as the immune response of a history of immunocompetent individuals. It can be used as a support indicator to establish sex. Of COVID-19.