21        340  – COVID

, . Nature.com  first published in 1869, Nature is the world’s leading multidisciplinary science journal.
: https://www.nature.com/articles/…
«How much do vaccines block transmission?»
«study by Public Health England has found that even a single dose of either the PfizerBioNTech or OxfordAstraZeneca vaccine reduced the spread of disease from infected individuals to household members by up to 50%.»-
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