Latest XBB COVID-19 vaccine offers protection against hospitalization, deaths

JAMA Internal Medicine published a study calculating the protection offered by the latest Pfizer COVID-19 XBB vaccine compared to older vaccines against COVID-associated hospitalization and emergency department (ED) or urgent care (UC) visits. The test-negative case-control study of the BNT162b2 XBB vaccine was performed among adults in the Kaiser Permanente Southern California health system from October 10 to December 10, 2023. XBB was the dominant strain of SARS-CoV-2 in the United States at that time but has since been supplanted by JN.1. The study included patients who presented with an acute respiratory illness and had a positive SARS-CoV-2 polymerase chain reaction test and controls who had an acute respiratory illness but tested negative for SARS-CoV-2. A total of 2,854 cases and 15,345 controls (median age, 56) were included in the studies. The authors compared outcomes among those who had received an updated XBB vaccine and those who had not received an XBB vaccine...