Vaccines are the solution to overcome SARS-CoV-2. This study aimed to determine the post-Sinopharm vaccine safety-profile and immunity through antibody titers. Data were collected using a structured questionnaire from Egyptian participants who received two doses of Sinopharm vaccine. Data were divided into three parts, the first and second parts were to detect participants' post-first and second dose symptoms and practices, and the third for the results of IgG anti spike protein antibodies test and laboratory tests. Pain, redness, swelling at the injection site, headache, fatigue, and lethargy were the most common post-vaccine symptoms for both first and second doses. Most of the participants felt mild or no symptoms after vaccination. The symptoms started mostly during the first day post-vaccination and lasted for no more than two days. Forty-nine percent of the participants resulted in positive antibodies tests on day 18 post-vaccination. The average antibody level for vaccinated participants with past SARS-CoV-2 infection was much higher than that for non-past infected participants. These vaccines' administration methods need to be reevaluated by changing the dose, dose interval, adding a third dose, or mixing it with other vaccines with different techniques to improve their protection rates. Further studies are required to validate this finding.
Keywords: COVID-19; IgG; SARS-CoV-2; Sinopharm vaccine; adverse effects; anti-spike.