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            4/21/2021 7:08AM     

            China Considers Boosting Covid-19 Vaccine Efficacy. Mixing Is One Way.

            Chinese Covid-19 vaccines offer relatively low levels of protection compared with some of their foreign rivals. Here is why China is joining other countries in considering mixing and matching vaccines as a key to overcoming multiple vaccination challenges at once. Illustration: Ksenia Shaikhutdinova

            正版资料大全全年2019小说