Only 37% of Americans got vaccinated for the flu last year, which is said to be one of the deadliest seasons in decades, according to a new report released Thursday by the Centers for Disease Control and Prevention.

Why it matters: The report suggests that a 6.2% drop in vaccination from the previous season could be factor behind the severity of last year’s season. The epidemic killed an estimated 80,000 Americans — the highest level for at least four decades. At least 180 children, 80% of whom were not vaccinated, were killed and there were 900,000 hospitalizations.