Background: Following the worldwide mass vaccination to prevent and protect the child population from the deadly virus, on 17th May 2021, the Primary Health Care Corporation (PHCC), Qatar launched the BNT162b2 COVID-19 vaccine campaign among adolescents i.e., 12 to 15 years of age across region through all 27 health centers. We estimated the safety and protective efficacy of the BNT162b2 COVID-19 vaccine among the vaccinated and non-vaccinated adolescent population in Qatar. Methods: A quantitative retrospective observational study assessed the medical records of SARS-COV-2 positive adolescents (12-15 years) of all 27 Primary Healthcare Centres of PHCC. All data were obtained during the second wave of the SARS-COV-2 pandemic from 17 ^th June 2021 to 17 ^th December 2021. Results: The study data involved 1956 SARS-CoV-2 infection (RTPCR positive) cases. Out of 1956 children, 20.55% were vaccinated (n=402) and 79.45% were non-vaccinated (n=1554). The mean age for the vaccinated group was 13.89 ± 0.93 and non-vaccinated group was 12.99 ± 0.93. The number of vaccinated participants 20.55% (n=402) of the total sample size who contracted SARS-CoV-2 infections was significantly lesser compared to the non-vaccinated population 79.45% (n=1554). Incidence of the SARS-COV-2 infection was found to be statistically significant among the vaccinated group who received 2 doses of Pfizer-BioNTech vaccine (p-value<0.001) rendering the vaccine effectiveness against prevention of the SARS-CoV-2 infections. Conclusion: In summary, our findings indicate that protection of Pfizer BioNTech (BNT162b2) COVID-19 vaccine against SARS-CoV-2 infections is satisfactory as only one-fifth of the total study population contracted SARS-CoV-2 infections after the double dose regimen. Our findings support the importance of maximizing vaccination coverage for considering booster doses for adolescents to enhance protection. Further studies will be needed to assess the duration of protection and immune-prophylactic response and the need for booster doses.