Figure 2. Characteristics of outbreak of SARS-CoV-2 B.1.1.7 lineage infections after vaccination in long-term care facility, Germany, February–March 2021. A) After a positive test result in a healthcare worker, 16/20 (80.0%) vaccinated residents and 4/4 (100.0%) unvaccinated residents subsequently tested positive for SARS-CoV-2. Among infected patients, 5/16 (31.25%) vaccinated and all 4 (100.0%) unvaccinated patients exhibited respiratory symptoms (i.e., cough or shortness of breath) during the course of disease. All 4 unvaccinated patients required hospital treatment; 3 (75.0%) received supplemental oxygen therapy and a standard course of dexamethasone. Two (12.5%) vaccinated patients also required hospital treatment, including 1 patient who experienced hypertensive crisis and intracranial bleeding and died 4 days after admission, and 1 patient with secondary bacterial pneumonia and urinary tract infection. B) Peak SARS-CoV-2 RNA concentrations in infected vaccinated residents (n = 16) and infected unvaccinated residents (n = 4), as well as SARS-CoV-2 B.1.1.7 RNA concentrations of an independent group of age-matched persons (n = 48) without known vaccination status whose infections were diagnosed during routine care. C) Time between first positive and first negative reverse transcription PCR or antigen point-of-care test result in vaccinated (n = 16) and unvaccinated (n = 4) residents. In 3 residents (2 vaccinated and 1 unvaccinated), negativity was determined by antigen point-of-care test only. D) Anti-SARS-CoV-2 receptor binding domain–specific IgG. E) IFN-γ release assay of SARS-CoV-2 specific T cells measured in 10/20 (50.00%) vaccinated and 2/4 (50.00%) unvaccinated residents 5 weeks after initial testing. IFN-γ, interferon-γ; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; S/CO, signal-to-cutoff ratio.