A comparative study of some biological variables in those vaccinated and unvaccinated with the COVID-19 vaccine in the city of Samarra
Republic of Iraq, Ministry of Education, Salah al-Din Education Directorate-Samarra Education Department,
Research Article
Open Access Research Journal of Biology and Pharmacy, 2026, 16(02), 050-059.
Article DOI: 10.53022/oarjbp.2026.16.2.0023
Publication history:
Received on 05 February 2026; revised on 12 March 2026; accepted on 14 March 2026
Abstract:
After the world was swept by the SARS-CoV-2 virus, it became necessary to stop and control the pandemic, so the vaccine was issued as one of the preventive measures to stop the pandemic. The effect of the Pfizer/BioNTech BNT162b2 vaccine in raising the body's immune capacity against the SARS-CoV-2 virus was studied. A comparative study was conducted on the inflammatory blood parameters, which are the total number of white blood cells (WBCs), neutrophils, lymphocytes, and C-reactive protein (CRP). These blood inflammatory parameters were compared among 3 groups (healthy, vaccinated and unvaccinated). The study was designed by dividing the sample of 90 participants (50 males and 40 females) into three groups: the first group included 30 healthy participants who were not infected with Covid-19 and were not vaccinated, the second group included 30 participants who were infected with the disease while they were not vaccinated, and the third group included 30 participants who were vaccinated with two doses and were infected again after vaccination (Breakthrough infection). The ages of the participants ranged from (21 to 60 years).
The study was conducted during the period between Dec. 2023 and May 2025, in private laboratories in Samarra city. We obtained the following results: The total white blood cell count was found to be highest in the group of unvaccinated patients (16.731 ± 4.303) and lowest in the healthy group (10.012 ± 0.601). Neutrophils were highest in vaccinated patients (7548.29 ± 798.171) and lowest in the healthy group (5891.25 ± 351.686). While the lymphocytes recorded the highest percentage in the healthy group (2779.92 ± 283.711) and the lowest percentage in the unvaccinated patients (1997.31 ± 290.039). As for the values of C-reactive protein (CRP), the highest values were recorded in the unvaccinated infected group (10.146 ± 4.752) and the lowest values were in the healthy group (1.550 ± 0.781). The ratio of neutrophils to lymphocytes was also obtained, where the highest percentage was in the unvaccinated infected (3.729), while the lowest percentage was recorded in the healthy group (1.958).
By studying these blood inflammatory parameters, it was found that the vaccine contributes to raising the body's immune capacity and reducing the possibility of infection, but it does not prevent infection completely. It also contributes to reducing the severity of infection if it occurs.
Keywords:
Covid-19; Sars-Cov-2; Vaccinated; Unvaccinated; Pfizer; White Blood Cells; Neutrophils; Lymphocytes; And C-Reactive Protein
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Copyright © 2026 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0