States with high vaccination rates can still experience COVID-19 surges — here’s why

“There are probably a number of factors contributing to the current spike,” Karen Edwards, [professor and] chair of the department of epidemiology and biostatistics at the University of California, Irvine Program in Public Health, told Healthline. “Some of the most likely factors are that as the weather gets colder, more people are gathering indoors and in closer proximity to each other, which facilitates transmission between individuals. There may also be less adherence to mask wearing, good hygiene, and social distancing …”