Individual and Environmental Risk Factors for COVID- 19 Mortality in Elderly (preprint)

Several studies have already explored individual and environmental risk factors for COVID-19 morality, however most study populations consisted of the overall population and mainly from China or the US. Our study focused on COVID-19 mortality in the elderly in seven European cities. Long-term exposure to air pollution was estimated through annual pollutant concentrations at the residential address averaged over the last two years of the study period between February and May 2020. We focused on the main outdoor air pollutants PM10, PM2.5, NO2 and O3. Short-term variations in air pollutants and weather parameters (e.g. temperature, UV, relative humidity) were also examined through a 20-day period before the confirmed PCR diagnostic of COVID-19. Individual risk factors such as smoking status, sex, body mass index (BMI), ischemic heart disease, diabetes, hypertension, chronic renal failure, history of cancer, COPD, and lung fibrosis, were taken into account. We found positive associations for diabetes and COVID-19 mortality (OR 2.2 CI 95% :1.1, 4.4). Using a multivariate logistic regression model adjusted for all patient characteristics and city, we fail to reject the null hypothesis of no association between COVID-19 mortality and long-term and short-term increase in PM2.5, PM10, NO2 and O3. Our study suffers from the fact that patient profiles strongly differ between high-polluted and less-polluted cities. Strong differences in COVID-19 mortalities were observed between cities, which could be due to differences in COVID-19 management and treatment, such as accessibility to reanimation and intensive units between cities. Overall, our study highlights the need to improve estimation of individual exposure to air pollution. Indeed, even with the high-efficiency modelisation systems used in our study, we were unable to estimate the effect of air pollution within each city, because variations in air pollution exposure were too small. Individual markers of air pollution exposure such as recently demonstrated with urinary black carbon or passive individual samplers, would be most suitable for future explorations. Concerning weather parameters, although previous studies concluded that increase in temperature and UV index could decrease COVID-19 morality, our data did not allow us to reject the null hypotheses.

Humoral immune response after COVID-19 infection or BNT162b2 vaccine among older adults: evolution over time and protective thresholds. (preprint)

INTRODUCTION The objectives of this study were to assess the dynamics of the SARS-CoV-2 anti-RBD IgG response over time among older people after COVID-19 infection or vaccination and its comparison with speculative levels of protection assumed by current data. METHODS From November 2020 to October 2021, we included geriatric patients with serological test results for COVID-19. We considered antibody titre thresholds thought to be high enough to protect against SARS-CoV-2 infection: 141 BAU/ml for protection/vaccine efficacy > 89.3%. Three cohorts are presented. A vaccine group (n=34) that received two BNT162b2/Comirnaty injections 21 days apart, a group of natural COVID-19 infection (n=32) and a third group who contracted COVID-19 less than 15 days after the first BNT162b2/Comirnaty injection (n=17). RESULTS 83 patients were included, the median age was 87 (81-91) years. In the vaccine group at 1 month since the first vaccination, the median BAU/ml with IQR was 620 (217-1874) with 87% of patients above the threshold of 141 BAU/ml. Seven months after the first vaccination the BAU/ml was 30 (19-58) with 9.5% of patients above the threshold of 141 BAU/ml. In the natural COVID-19 infection group, at 1 month since the date of first symptom onset, the median BAU/ml was 798 (325-1320) with 86.7% of patients above the threshold of 141 BAU/ml and fell to 88 (37-385) with 42.9% of patients above the threshold of 141 BAU/ml at 2 months. The natural infection group was vaccinated three months after the infection. Five months after the end of the vaccination cycle the BAU/ml was 2048 (471-4386) with 83.3% of patients above the threshold of 141 BAU/ml. DISCUSSION On the humoral level, this supports the clinical results describing the decrease in vaccine protection over time.

Interest of Proton Pump Inhibitors in Reducing the Occurrence of COVID-19: A Case-Control Study (preprint)

Background: COVID-19 is a disease of the elderly as 95% of deaths related to COVID-19 occur in people over 60 years of age. Despite the urgent need for a preventive treatment there are currently no serious leads, other than the vaccination. Objective: To find a preventive treatment of COVID-19 in elderly patients. Design: Retrospective case-control study. Setting: Robertsau Geriatric Hospital of the University Hospitals of Strasbourg, France. Patients: 179 elderly patients who had been in contact with the SARS-CoV-2, of whom 89 had tested RT-PCR-positive (COVID-pos) for the virus and 90 had tested RT-PCR-negative (COVID-neg). Measurements: Treatments within 15 days prior to RT-PCR (including antihypertensive drugs, antipsychotics, antibiotics, nonsteroidal anti-inflammatory drugs, proton pump inhibitors (PPIs), paracetamol, anticoagulant, oral antidiabetics (OADs), corticosteroids, immunosuppressants), comorbidities, symptoms, laboratory values, and clinical outcome were all collected using the electronic patient record. Results: COVID-pos patients more frequently had a history of diabetes (P=.016) and alcoholism (P=.023), a lower leukocyte count (P=.014) and a higher mortality rate– 29.2% versus 14.4% – (P=.014) when compared to COVID-neg patients. Patients on PPIs were 2.3 times less likely (odds ratio [OR] = 0.4381, 95% confidence interval [CI] [0.2331, 0.8175], P=.0053) to develop COVID-19 infection, compared to those not on PPIs. No other treatment decreased or increased this risk. COVID-19 patients on antipsychotics (P=.0013) and OADs (P=.0166) were less likely to die. Limitations: retrospective study. Conclusion: PPIs treatment lowered the risk of development of COVID-19 infection, and antipsychotics and OADs decreased the risk of mortality in geriatric patients. If further studies confirm this finding, PPIs could be used preventatively in the elderly in this pandemic context. Moreover, OADS and antipsychotics should be tested in clinical trials.