Reinfection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has been documented all over the world. Currently, limited evidence exists concerning the protection afforded by the COVID-19 vaccination against reinfection with SARS-CoV-2. This case-control study was performed in order to assess the association between COVID-19 vaccination and SARS-CoV-2 reinfection in the Babil Province; the study used an electronic questionnaire. The infected patients were 115 (aged ≥18 years) and were confirmed by a positive PCR and/or a CT scan, they were either fully vaccinated or not with a second dose of a (Pfizer, AstraZeneca, or Sinopharm) vaccine before the reinfection date, and they were compared with 300 control participants. The study’s findings revealed that the unvaccinated individuals had 4.5 times the odds of reinfection compared to those who were fully vaccinated, without preference for the manufacturer of the vaccine. The conclusion suggests that getting fully vaccinated against COVID-19 can significantly reduce the likelihood of reinfection, can enhance overall protection, and can minimize the risk of future infections.