Abstract: Immunizations are important tools in preventive medicine and should be encouraged by the AME. Since vaccines are not reportable upon medical certification, it is important for the AME to advise pilots regarding common side effects of the inactive vaccines and how they can affect aviation safety.

Aeromedical folklore describes the tragic death of Lieutenant Sidney J. Brooks from a delayed vaccine reaction. The unfortunate Cadet, for whom Brooks Air Force Base is named, reportedly died on his final solo flight after a series of vaccinations. Several unexplained aspects of Lt. Brooks' controlled flight into terrain still exist; however, his case exemplifies why the aviation medical examiner (AME) should be concerned with immunizations and flying. Furthermore, the recent use of Anthrax vaccine by the military has unjustifiably concerned pilots.

In general, immunizations are not disqualifying for general aviation flying. And although the Federal Aviation Administration (FAA) recently expanded Box 17(a) on Form 8500-8 to include "Any Medication," it was not their intent to include vaccine prescriptions. Pilots do not have to report receipt of any vaccine on their FAA medical application. It is, therefore, incumbent upon the AME to counsel the aviator on potential vaccine side effects and their affect on flight safety.

Vaccines come in two different forms, live and inactive. Live vaccines utilize weakened or dead organisms to stimulate an antibody response from the body. They are typically dosed once during childhood, and this provides long-term immunization. Examples of live vaccines include the varicella, oral typhoid, measles, mumps, and rubella vaccines. Pediatricians are usually concerned about the rare and debilitating side effects of a live vaccine; however, it is the inactive vaccine that concerns the AME.

Inactive vaccines have no live organisms and are more stable, but immunologically weaker. Because of this "weakness," they require multiple dosing. Examples of inactive vaccines include intramuscular typhoid, tetanus, influenza, and Anthrax . About 85% of adverse vaccine event reports concern relatively minor events — ordinary fevers or redness and swelling at the injection site. The remaining 15% describe serious events, such as seizures, high fevers, life-threatening illnesses, or deaths. Inactive vaccines are the type most likely administered to pilots and tend to have less serious side effects. Unfortunately, inactive vaccines have more common minor reactions than the live vaccines.

The National Childhood Vaccine Injury Act of 1986 (NCVIA) requires health care providers and vaccine manufacturers to report to the Department of Health and Human Services (DHHS) specific adverse events following the administration of vaccines. The DHHS established the Vaccine Adverse Event Reporting System (VAERS), which is co-administered by the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC), to accept all reports of suspected adverse events, in all age groups, after the administration of any US-licensed vaccine. The primary purpose for maintaining the database is to serve as an early warning or signaling system for adverse events not detected during pre-market testing. The AME should be aware of this database and be able to provide the airman with a general description of side effects from various vaccinations.

The most common minor side effect from parenteral vaccination with an inactive vaccine is local arm soreness, headache, fever, and fatigue. These seemingly minor symptoms on land could, of course, distract or physically limit the pilot in the air. Furthermore, since there is no minimum grounding period after receiving immunizations, it is incumbent upon the aviator to anticipate minor symptoms and plan crew rest accordingly. Taking aspirin or acetaminophen after an immunization may minimize minor side effects; whereas, more serious side effects may be temporarily "self" grounding until they resolve or stabilize. As always, pursuant to the Federal Aviation Regulations, it is the pilot's ultimate responsibility to be "fit for flight."

One final point: On 15 October 1999, Federal Air Surgeon Dr. Jon Jordan, posted a letter formally articulating the FAA policy on pilots receiving the Anthrax vaccine. The letter confirmed that receiving the Anthrax vaccine does not affect a pilot's medical certificate and confirmed that receipt of the vaccine is not cause for grounding for any duration. Individuals who have been immunized with the Anthrax vaccine are not disqualified from performing civilian airman duties so long as they do not experience significant side effects that would otherwise be considered disqualifying.

In sum, immunizations play a very important role in preventive medicine and should be encouraged by the AME. Since vaccines are not reportable upon medical certification, it is important for the AME to advise pilots regarding common side effects of the inactive vaccines and their impact on flight safety.

Dr. Borrillo is the Chief of Flight Medicine, 352nd Operations Support Squadron, USAF Special Operations Command, Royal Air Force Base, Mildenhall, England. He is Board certified in Aerospace Medicine. In addition, he is a commercial pilot, an AME, and a practicing attorney.

The Federal Air Surgeon's Medical Bulletin • Winter 2000