On Aug. 26, 2021, Oregon Health & Science University (OHSU) announced that a laboratory studyhad found that blood serum drawn from people previously vaccinated or naturally infected showed ﾓsignificantly reducedﾔ defense against two widely circulating variants of the novel coronavirus SARS-CoV-2.

Researchers found two variants of concern ﾖ B.1.1.7 originating in the U.K., and B.1.351 originating in South Africa ﾖ showed reduced neutralization by antibodies in the blood of almost 100 people who were vaccinated with the Pfizer vaccine or previously infected by the virus.