What Is the Risk of Developing a Severe Form of COVID-19 Infection Among Adults Who Currently Smoke Compared to Ex-smokers? Protocol for a Systematic Review and Meta-analysis. IPS J Public Health [Internet]. 2025 Dec. 12 [cited 2026 Jun. 3];5(4):515-8. Available from: https://journals.ipsintelligentsia.com/public-health/index.php/ijph/article/view/90