Anti-spike IgG antibody kinetics following the second and third doses of BNT162b2 vaccine in nursing home residents.

BACKGROUND: Duration of post-vaccination protection against COVID-19 in nursing home (NH) residents is a critical issue. The objective of this study was to estimate the duration of the IgG(S) response to the mRNA BNT162b2 vaccine in NH residents with (COV-Yes) or without (COV-No) history of SARS-CoV-2 infection. METHODS: A 574 COV-Yes and COV-No NH residents were included in 2 cohorts: Main (n = 115, median age 87 years) or Confirmatory (n = 459, median age 89 years). IgG(S) quantification was carried out at three different time points following the BNT162b2 vaccine: three (1st) and seven (2nd) months after the 2nd dose, and 1 month after the 3rd dose (3rd quantification) in the Main cohort, and twice (2nd and 3rd) in the Confirmatory cohort. The seroneutralization capacity according to COVID-19 history was also measured in a subgroup of patients. RESULTS: Neutralization capacity was strongly correlated with IgG(S) levels (R2 :76%) without any difference between COV-Yes and COV-No groups for the same levels of IgG(S). After the 2nd dose, duration of the assumed robust protection (IgG(S) >264 BAU/ml) was two-fold higher in the COV-Yes vs. COV-No group: 12.60 (10.69-14.44) versus 5.76 (3.91-8.64) months, with this advantage mainly due to the higher IgG(S) titers after the 2nd dose and secondary to a slower decay over time. After the 3rd dose, duration of robust protection was estimated at 11.87 (9.88-14.87) (COV-Yes) and 8.95 (6.85-11.04) (COV-No) months. These results were similar in both cohorts. CONCLUSIONS AND RELEVANCE: In old subjects living in NH, history of SARS-CoV-2 infection provides a clear advantage in the magnitude and duration of high IgG(S) titers following the 2nd dose. Importantly, the 3rd dose induces a much more pronounced IgG(S) response than the 2nd dose in COV-No subjects, the effect of which should be able to ensure a prolonged protection against severe forms of COVID-19 in these subjects.

Evidence of a Blood Pressure Reduction During the COVID-19 Pandemic and Associated Lockdown Period: Insights from e-Health Data.

Introduction: Despite widespread investigation into the incidence of acute myocardial infarction during the coronavirus disease 2019 (COVID-19) pandemic and associated lockdown, no study has examined the situation's impact on blood pressure (BP) levels. Methods: Measurements of BP and heart rate (HR) were obtained from persons living in the Paris urban area using connected home BP monitors (accessible to patients and health providers through a secured server). Three time periods of e-health recordings were compared: during the pandemic before the lockdown, during the lockdown, and the same time period in 2019. Results: A total of 297,089 BP recordings from 2,273 participants (age 56.3 ± 12.8 years, 81.1% male) were made. During confinement, systolic BP gradually decreased by 3 mmHg (-2.4 to -3.9), and diastolic BP by 1.5 mmHg (-1.4 to -2.2) (all p < 0.001); this decrease was greater for participants with higher BP (p < 0.0001 each). No significant variation in HR was noted. Conclusion: Among a very large cohort, we observed a significant decrease in home BP measured with e-health devices during the first lockdown period. This study emphasizes the research potential of e-health during the COVID-19 crisis.