Vaccine Breakthrough Infections of SARS-Cov-2: A Case Report

Novel mRNA vaccines provide a high degree of protection against COVID-19 infection, hospitalisation, and death. However, no vaccine claimed 100% effectiveness and it is expected that a small proportion of vaccinated individuals may develop a breakthrough infection. There is a concern relating to the ability of variants to evade vaccine-induced immunity that leads to asymptomatic infection or occasionally progress to disease. The extent of this ability is largely unknown.

An 88-year-old male patient was brought to the emergency department on July 25, 2021, with a presentation of a lower respiratory tract infection. He was screened for SARS-CoV-2, and tested positive for the reverse transcription-polymerase chain reaction (RT-PCR) test for SARS-CoV-2. According to the patient, he was diagnosed with benign prostatic hyperplasia (BPH) after a prostate biopsy in 2015 but, at the time of admission, he was not taking any chronic medication. He received the first dose (batch no. FA7812) of the Pfizer-Biotech vaccine on June 8, 2021, and the second dose (batch no. FE2090) on July 20, 2021. He was admitted to the isolation ward with a diagnosis of vaccine breakthrough COVID-19 infection and BPH.

This case report highlights the issue of vaccine breakthrough infections and the potential risk of contracting the COVID-19 disease despite successfully receiving two doses of the Pfizer-BioNTech vaccine six weeks apart.