Publication Details
Issue: Vol 4, No 4 (2023)
Pages: 273-280
ISSN: 2660-4159

Abstract

Background: Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 is an contagious illness that emerged in December 2019, remains a serious threat it has caused millions of deaths around the world, resulting in a global pandemic. COVID-19 vaccines protect against this severe illness through different approaches. Sinopharm and Pfizer-BioNTech COVID-19 vaccines were the greatest used vaccines in Iraq. Both vaccines have a specific mechanism to activate the immune system in human body.
This research aims to assessment the complement system C3 and C4 responses in vaccinated individuals with each the Pfizer-BioNTech COVID-19 vaccine or the Sinopharm vaccine.
Methods
The study included 180 Iraqi adults vaccinated with two doses, 1 week apart, using either the Sinopharm or Pfizer-BioNTech vaccine sixty person received the Pfizer vaccine, sixty person received the Sinopharm vaccine, and the other sixty subjects were un-vaccinated. After one week, the second dose was administered, and the blood samples were collected.
Results




study findings shown that Complement system 3 (C3) and (C4) levels were significantly increased (P-value=< P<0. 05) in total vaccinated groups when compared with healthy control. also . the table was indicated C3 concentration was significantly high increased in first dose compared to second dose on vaccinated group , while the C4 concentration was non-significantly between two dose groups.
The study concluded that the Pfizer-BioNTech and Sinopharm vaccine boosted the immune system by high activation complement may also have a protective role and could function to enhance virus neutralization by antibodies, promote virus phagocytosis by immune cells, and lysis of coronavirus.

Keywords
SARS-CoV-2 COVID-19 vaccines Complement system C3 Complement C4