Muhammad Kashif Munir, Sana Rehman, Ayesha Aftab, Muhammad Amer Nazir, Akhtar Ali, Naeem Asghar. “Impact of Vaccination on Symptomatology Among COVID-19 Infection and Re-Infection”. Pakistan Journal of Medical & Health Sciences, vol. 16, no. 12, Jan. 2023, p. 93, doi:10.53350/pjmhs2022161293.