Vaccination has proven to be one of the most effective strategies against the COVID 19 pandemic. Several studies have evaluated and confirmed its effectiveness in different populations, particularly in reducing severe outcomes such as hospitalization and death. However, the potential of vaccination to protect against infection itself has been overlooked. The aim of this study was to determine the effectiveness of the booster dose in a sample of Colombian patients during the fourth wave of COVID-19 pandemic, which was associated with the emergence and predominance of the Omicron variant. A cross-sectional study was conducted on individuals who underwent RT-PCR testing for COVID-19 detection in a dedicated laboratory in Bogotá, Colombia, between December 30th 2021 and February 7th 2022. A total of 1,468 subjects were included in the study. The comparison between fully vaccinated individuals with a booster dose and those without the booster dose revealed a 28% reduction in the odds of infection (OR = 0.719 CI 0.531 - 0.971). Age (OR = 1,009 CI 1,001 - 1,018) and low economic status (OR= 1,812 CI 1,416- 2,319) were associated with an increased risk of infection.These findings suggest the need for booster vaccination in the general population to improve the prevention rates of SARS-CoV-2 infection and mitigate severe outcomes.