COVID vaccines may have saved 19,000 lives in under a year in CaliforniaA modeling study estimates that COVID-19 vaccination prevented more than 1.5 million infections, 72,000 hospitalizations, and 19,000 deaths in the first 10 months of vaccination in California, according to a study published late last week in JAMA Network Open.University of California researchers created a statistical model using person-level data from the California Department of Public Health to estimate COVID-19 cases that would have occurred if vaccination hadn't been widely available from Nov 29, 2020, to Oct 16, 2021.
The study period included the Delta, but not the Omicron, variant surge.During the study period, 3,276,260 COVID-19 cases, 240,718 hospitalizations, and 70,406 deaths occurred, and 164,680 eligible residents (aged 12 and older) received at least one dose of COVID-19 vaccine, for a vaccination rate of 79.5%.
Roughly 57% of vaccinees received the Pfizer/BioNTech vaccine, while 36% received Moderna, and 7% received Johnson & Johnson. "Both risk of hospitalization and risk of death varied over time and across age groups and was highest in the population aged 65 years or older (21.6% of reported cases resulted in hospitalization and 10.8% of reported cases resulted in death)," the study authors wrote.According to the model, COVID-19 vaccination prevented 1,523,500 infections (95% prediction interval [PI], 976,800 to 2,230,800), corresponding to a 72% (95% PI, 53% to 91%) relative reduction.
Vaccination also averted an estimated 72,930 hospitalizations (95% PI, 53,250 to 99,160) and 19,430 deaths (95% PI, 14,840 to 26,230).The authors said that the estimates are likely a lower bound and that the results may be generalizable to the rest