Safety of anthrax vaccine: a review by the Anthrax Vaccine Expert Committee (AVEC) of adverse events reported to the Vaccine Adverse Event Reporting System (VAERS).

PURPOSE: To assess the safety of a licensed anthrax vaccine given to nearly 400,000 US military personnel, reports of adverse events (AEs) submitted to the Vaccine Adverse Event Reporting System (VAERS) were reviewed and evaluated medically. METHODS: The Anthrax Vaccine Expert Committee (AVEC), a civilian panel of private-sector physicians and other scientists, reviewed 602 VAERS reports using a Delphic approach (structured expert consensus) to assess the causal relationship between vaccination and the reported AEs and sought to identify unexpected patterns in the occurrence of medically important events. Reports were entered into a database and used to profile AEs with respect to person, type/location, relative frequency, severity/impact, concomitant illness or receipt of other drugs or vaccines, and vaccine lot. RESULTS: Nearly half the reports noted a local injection-site AE, with more than one-third of these involving a moderate to large degree of inflammation. Six events qualified as serious AEs (SAEs), and all were judged to be certain consequences of vaccination. Three-quarters of the reports cited a systemic AE (most common: flu-like symptoms, malaise, rash, arthralgia, headache), but only six individual medically important events were judged possibly or probably due to vaccine (aggravation of spondyloarthropathy (2), anaphylactoid reaction, arthritis (2), bronchiolitis obliterans organizing pneumonia). CONCLUSIONS: Since some cases of local inflammation involved distal paresthesia, AVEC recommends giving subcutaneous injections of AVA over the inferior deltoid instead of the triceps to avoid compression injury to the ulnar nerve. At this time, ongoing evaluation of VAERS reports does not suggest a high frequency or unusual pattern of serious or other medically important AEs.

Safety of anthrax vaccine: an expanded review and evaluation of adverse events reported to the Vaccine Adverse Event Reporting System (VAERS).

PURPOSE: To assess the safety of a licensed anthrax vaccine (AVA) given to more than 500,000 US military personnel, through review and medical evaluation of adverse events (AEs) reported to the Vaccine Adverse Event Reporting System (VAERS). METHODS: AEs were summarized by person, vaccine lot, type, frequency and impact. A Delphic approach was used to tentatively assess causality in an effort to detect serious AEs (SAEs) or other medically important AEs (OMIAEs) possibly attributable to AVA. RESULTS: The Anthrax Vaccine Expert Committee (AVEC) reviewed 1841 reports describing 3991 AEs (9.4 reports/10,000 doses of AVA) that were submitted to VAERS from 1Q1998 through 4Q2001. One hundred forty-seven reports described an SAE or OMIAE, of which 26 were tentatively rated as possible, probable or certain consequences of vaccination (injection-site reaction [12], 'anaphylactic-like reaction' [5] and eight other systemic AEs [1-2 each]). CONCLUSIONS: This review produced no evidence for an unusual rate of any SAE or OMIAE attributable to AVA. It supported an earlier impression that AVA may cause significant local inflammation and should be administered over the deltoid rather than the triceps to avoid direct or compression injury to the ulnar nerve. The subjects of VAERS reports tended to be older than all recipients of AVA. Females generally had and/or reported AEs more often than males, but transient articular reactions were surprisingly more common in males. Variations in the frequency or severity (as judged by hospitalization and/or loss of duty) of reported AEs did not suggest a significant problem with (1) a particular lot of AVA, (2) recurrent AEs after multiple doses or (3) vaccination of persons with a concomitant illness or those given other vaccines or medications.