Examining Socioeconomic and Computational Aspects of Vaccine Pharmacovigilance

Figure 5

Immunization is an active field of study: a number of publications in PubMed (upper, left) and of clinical trial features from clinicaltrials.gov (remaining plots) mentioned “vaccine” or “vaccination” or “immunization.” On a historical note, another 67932 publications have been published prior to 1980 with the oldest one dating back up to 1819. Red color refers to 1623 vaccine trials that are “running” defined as those that have recruitment status “Active, not recruiting,” “Enrolling by invitation,” “Not yet recruiting,” or “Recruiting” (middle). Of those, 527 (32%) refer to conditions mentioning the terms neoplasm, cancer, tumor, melanoma, glioma, leukemia, or neuroblastoma. Upper, right: many current trials study the effectiveness of vaccines. Notably, there are as many Phase III trials (last premarketing stage) as in Phase IV (post-FDA approval stage). Lower, left: 49.6% of vaccine related trials involve industry funds. Category “other” denotes academic and research organizations, hospitals, military/defense centers, as well as non-US institutions and authorities, governments, universities, and international and nonprofit organizations. In comparison, VAERS mentions vaccines from 39 manufacturers. Lower, middle: most vaccine trials tend to be interventional (participants are assigned to groups) rather than observational (often retrospective). Lower, right: unfortunately, many trial results are not made available, hindering thus transparency and reproducibility.