The patient had symptomatic infection despite having completed vaccination with Pfizer-BioNTech mRNA vaccine, including booster approx 6 weeks prior to symptom onset; The patient had symptomatic infection despite having completed vaccination with Pfizer-BioNTech mRNA vaccine, including booster approx 6 weeks prior to symptom onset;  A female patient in her 30's received BNT162b2 (BNT162B2), in 2021 as dose 1, single (Batch/Lot number: unknown), in 2021 as dose 2, single (Batch/Lot number: unknown) and in Oct2021 as dose 3 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "upper respiratory symptoms" (unspecified if ongoing); "COVID-19", start date: 2019 (unspecified if ongoing). The patient's concomitant medications were not reported. The following information was reported: DRUG INEFFECTIVE (medically significant), COVID-19 (medically significant), outcome "unknown" and all described as "The patient had symptomatic infection despite having completed vaccination with Pfizer-BioNTech mRNA vaccine, including booster approx 6 weeks prior to symptom onset". The patient underwent the following laboratory tests and procedures: focus reduction neutralization test: Unknown result; Unknown result; sample detected a variant sequence at amino acid, notes: Within 24 hours after sample collection; Polymerase chain reaction: positive; negative; negative, notes: 48 hours prior to return travel; cycle threshold value of 22.2; SARS-CoV-2 antibody test: positive.  Clinical information: It was identified that a previously healthy woman in her 30s who presented with upper respiratory symptoms following a trip to Withheld and was diagnosed with coronavirus disease 2019 (COVID-19) on return to Withheld, in November 2021, 4 days after identification of Omicron as a VOC. She was fully vaccinated with the Pfizer-BioNTech BNT162b2 mRNA vaccine as of February 2021 and had received a booster of the same vaccine in early October 2021. She had a negative poly¬merase chain reaction (PCR) test prior to departing and wore a medical-grade procedure mask and glasses on all flights. She stayed in a hotel in Withheld for 6 days and attended an indoor, unmasked event with 9 family mem¬bers and friends, 4 of whom subsequently also tested positive for SARS-CoV-2. She had a negative PCR test 48 hours prior to return travel while asymptomatic but then developed mild con¬gestion on her last day in Withheld, followed by a sore throat during travel home the next day. After arrival in Withheld, she also began experiencing nausea, fatigue, cough, and myalgias. She therefore had nasopharyngeal PCR testing performed at a community testing site on day 3 after symptom onset, which was positive. This sample was unable to be located during a con¬tact tracing investigation. She never developed fevers, shortness of breath, or chest discomfort and did not require medical at¬tention. All symptoms had resolved by day 9, with the exception of ongoing myalgias and significant fatigue.; Sender's Comments: Based on available information and the temporal association, a possible contributory role of Comirnaty vaccine cannot be excluded for the reported events of "DRUG INEFFECTIVE " and "COVID-19 ".