A Comprehensive Health Effects Assessment of the Use of Sanitizers and Disinfectants during COVID-19 Pandemic: A Global Survey (preprint)

COVID-19 has affected all aspects of human life so far. From the outset of the pandemic, preventing the spread of COVID-19 through the observance of health protocols, especially the use of sanitizers and disinfectants was given more attention. Despite the effectiveness of disinfection chemicals in controlling and preventing COVID-19, there are critical concerns about their adverse effects on human health. This study aims to assess the health effects of sanitizers and disinfectants on a global scale. A total of 91056 participants from 154 countries participated in this cross-sectional study through an electronic questionnaire. Results implied that detergents (67%), alcohol-based materials (56%), and chlorinated compounds (32%) were the most commonly used types of sanitizers and disinfectants. Most frequently reported health issues include skin complications 48.8% and respiratory complications 29.8%. The Chi-square test showed a significant association between chlorinated compounds with all possible health complications under investigation (p-value < 0.001). Examination of risk factors based on multivariate regression analysis showed that alcohols-based materials were associated with skin complications (OR, 1.98; 95%CI, 1.87–2.09), per-chlorine was associated with eye complications (OR, 1.83; 95%CI, 1.74–1.93), and highly likely with itching and throat irritation (OR, 2.00; 95%CI, 1.90–2.11). Furthermore, formaldehyde was associated with a higher prevalence of neurological complications (OR, 2.17; 95%CI, 1.92–2.44). The findings of the current study suggest that health authorities need to implement more awareness programs about the side effects of using sanitizers and disinfectants during viral epidemics.

Safety of Pfizer-BioNTech vaccine in a cohort of healthcare providers: differences between naïve and previously infected. (preprint)

Introduction: The Spanish Society of Immunology recently warned that a history of past COVID-19 could result in a higher incidence of adverse events (AEs) related to vaccination. We set out to analyze whether there were any differences in AEs between healthcare workers vaccinated for COVID-19 (either after the first or second dose) who had had a prior diagnosis SARS-CoV-2 infection compared to those who had not had COVID-19 before vaccination. Methods: This was a retrospective cohort study in a population of healthcare workers. AEs related to the first and second doses of the Pfizer vaccine were recorded. We compared the incidence of AEs and compared individuals with 0–3 different AEs to those with 4 or more AEs. The relative risks (RR) and their 95% confidence intervals were calculated. Results: Past infection was associated with having more AEs after the first dose (p < 0.001), but not the second one (p = 0.476), as well as a higher incidence of AEs (p < 0.001). Common AEs that were statistically associated with past COVID infection included arthralgia, asthenia, fever, chills, headache, and myalgia (p ≤ 0.001). The RR for having an increased absolute number of different AEs was 1.18 (95%CI [1.05, 1.33]) after the first dose and 1.05 (95%CI [0.96, 1.14]) after the second dose. Conclusions: Our results showed that the incidence of AEs was higher in individuals with a history of prior COVID-19 infection.