{'fraction_non_alphanumeric': 0.024390243902439025, 'fraction_numerical': 0.006097560975609756, 'mean_word_length': 5.15625, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Can the safety of the yellow fever vaccine be evaluated by a retrospective study of databases?

Nordin et al. assessed the quality of data in two databases, the Vaccine Safety Datalink (VSD) and the US Department of Defense (DoD), for adverse events that occur after yellow fever vaccine.1 The issues are as follows:

(1) Can the adverse events be attributed solely to yellow fever vaccine? No, 85% of the adults and 75% of the pediatric subjects in the VSD database received other vaccines and those vaccines were not stated. The authors state that the DoD database did not list other vaccines given (and military personnel are usually given multiple vaccines). Reports of adverse events after vaccination to pharmacovigilance databases usually involve several vaccines given simultaneously, and identifying whether a specific vaccine was responsible is usually impossible. Thus, separating reports for patients who received only yellow fever vaccine from those who received yellow …