1. WorldOMeter, COVID-19 Coronavirus pandemic. WorldOMeter; 2021. Available from: https://www.worldometers.info/coronavirus/. Accessed October 13, 2021.
2. Immunity and immunopathology to viruses: what decides the outcome?
3. Johns Hopkins Medicine. The Immune System. Johns Hopkins Medicine; 2021. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/the-immune-system. Accessed October 13, 2021.
4. National Institutes of Health. Lasting immunity found after recovery from COVID-19. National Institutes of Health; 2021. Available from: https://www.nih.gov/news-events/nih-research-matters/lasting-immunity-found-after-recovery-covid-19. Accessed October 13, 2021.
5. Laing K. Immune responses to viruses. British Society for Immunology; 2021. Available from: https://www.immunology.org/public-information/bitesized-immunology/pathogens-and-disease/immune-responses-viruses. Accessed October 13, 2021.