去年九月更低是七分之一

The data from the Red Cross mirrors findings from a Pew Research Center survey last month. They found 25% of Americans said they have had COVID-19, or about one-in-four people. In a survey in September, that number was closer to one-in-seven Americans who said they had contracted COVID-19.

The prevalence of COVID-19 antibodies in blood donations has been increasing, according to the data. Only about 1.5% of blood donations in July had antibodies, which increased to 4% in October and 12% in January. In the first week of March, it was 21%.