Minorities and people aged 65 years and older are underrepresented in vaccine clinical trials compared to the U.S. population, but women are overrepresented in such trials, according to a cross-sectional study of hundreds of vaccine trials conducted over the past decade.

The study, conducted by researchers across the U.S. and Puerto Rico, looked at 230 U.S.-based vaccine trials that collectively included 219,555 participants, but because only 134 (58.3 percent) of the trials reported data by race and 79 (34.3 percent) by ethnicity, the study pool of adult participants was reduced to 49,459.

The study examined data from completed U.S.-based vaccine trials that were registered on the ClinicalTrials.gov website from July 1, 2011, through June 30, 2020. Whites made up 77.9 percent of the vaccine trial population, which was above their share of the U.S. population in 2011 and 2018 (74.1 and 76.3 percent, respectively), according to U.S. census data. Meanwhile, Hispanic or Latino individuals made up 11.6 percent of trials, but accounted for 16.7 and 18.5 percent of the U.S. population in 2011 and 2018, respectively.

Black or African American participants made up 10.6 percent of the vaccine trials studied but were 12.6 and 13.9 percent of the U.S. population in 2011 and 2018, respectively. Shortfalls were also observed for Asian (5.6 percent in trials; 4.8 and 5.9 percent in census data) and American Indian or Alaska Native (0.4 percent in trials; 0.8 and 1.3 percent in census data) participants, while Hawaiian or Pacific Islander participants matched the census data at 0.2 percent in both 2011 and 2018.

Meanwhile, 56 percent of vaccine trial participants identified as female, and they accounted for 51.5 percent of the U.S. population in 2011 and 50.8 percent in 2018. Among the 170 studies reporting age as a percentage, 12.1 percent of participants were aged 65 years or older, but accounted for 16 percent of the U.S. population in 2018. When analyzed by phase, older adults were underrepresented across all trial phases, but their greatest participation was in phase 3 trials.

The study was published by JAMA Network Open. Read the study here: http://bit.ly/3uh6GgE.