Alsulaiman, Jomana W, Ashraf I Khasawneh, and Khalid A Kheirallah. 2020. “Could ‘trained immunity’ Be Induced by Live Attenuated Vaccines Protect Against COVID-19? Review of Available Evidence”. The Journal of Infection in Developing Countries 14 (09):957-62. https://doi.org/10.3855/jidc.12805.