There's little doubt now -- study after study, in real life and in lab dishes, in the US and elsewhere -- that people's immunity starts to wane just months after they finish the two-dose series of Pfizer Covid-19 vaccine.
원문출처 : https://www.cnn.com/2021/10/09/health/pfizer-covid-vaccine-waning-questions-wellness/index.html
원문출처 : https://www.cnn.com/2021/10/09/health/pfizer-covid-vaccine-waning-questions-wellness/index.html