Volume 28, Number 2—February 2022
Research
Comparative Effectiveness of Coronavirus Vaccine in Preventing Breakthrough Infections among Vaccinated Persons Infected with Delta and Alpha Variants
Figure

Figure. Distribution of Ct paired mean (reverse-transcription PCR Ct values for nucleocapsid and open reading frame 1ab genes) by coronavirus variant and vaccination status, Portugal, epidemiologic weeks 20–26 (May 17–July 4), 2021. A) Delta variant; B) Alpha variant. Box top and bottom indicate first and the third quartiles of Ct distribution, horizontal line inside box indicates median, and whiskers indicate minimum and maximum values. Ct, cycle threshold.
1These first authors contributed equally to this article.
2Members of the PT-Covid-19 Group are listed at the end of this article.