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Smallpox vaccine side effects ‘rare’

  • Published
  • By Army Sgt. 1st Class Doug Sample
  • American Forces Press Service
Mass smallpox vaccinations can be conducted safely with "very low" rates of serious adverse effects, the Defense Department's senior medical official said June 25.

The military will continue with its vaccination program because the smallpox bioterror threat remains, said Dr. William Winkenwerder, assistant secretary of defense for health affairs.

"Although we are no longer vaccinating servicemembers at the rate we witnessed earlier in the program, we continue to vaccinate those who are serving or who soon will be serving in high-risk areas," he said. "Our experience demonstrates that on a large scale the smallpox vaccination program can be conducted safely."

There are risks associated with the smallpox vaccination, even though significant side effects are rare, and death is very rare, Winkenwerder said.

"Our experience is that it is possible to reduce those risks associated with the vaccine," he said.

According to information from the five and a half-month military study, DOD officials administered 450,293 vaccinations, including more than 50,000 per week at the peak of the military program.

The study began Dec. 13, the day after President George W. Bush announced the plan to vaccinate the military, and ended May 28.

The study proved that the vaccine was administered without many adverse reactions, such as skin irritation and blister rashes, or risks associated with it, said Army Col. John D. Grabenstein. He is the Military Vaccine Agency’s deputy director for clinical operations.

Grabenstein wrote a report on the vaccination study with Winkenwerder. In it, he said that adverse incidents were not as apparent as historical data would suggest.

"Itching at the vaccination site was reported by about 60 percent of those vaccinated," Grabenstein said. Also, cases of "blister rashes” were mild, and they were treated on an outpatient basis.

He also said 3 percent needed to take sick leave after being vaccinated. That leave lasted roughly a day and a half, he said.

Comprehensive training of medical staff, education and careful screening of servicemembers, and close monitoring following vaccination were identified as ways to keep risks to a minimum. Early intervention when adverse events occur was also identified, according to Winkenwerder.

He said the study found no cases of transmission of vaccine virus from the health-care worker to the patient.

However, there were some concerns identified in the study. Winkenwerder said acute myopericarditis -- inflammation of the membrane covering the heart -- occurred in a small number of servicemembers who received the vaccine: about 1 in 12,000, or 37, people.

"All of these individuals have recovered or they are recovering, and we will continue to follow them," he said.

Grabenstein also refuted media accounts of the vaccine causing heart attacks in servicemembers.

"We have had several heart attacks among (those receiving) smallpox vaccines, but no more than we have had among a similar amount of unvaccinated people," he said. "So our conclusion is that heart attacks and smallpox vaccination are unrelated."

Information learned from the study will provide the American medical community and public with "current, factual information that will be useful as the U.S. moves forward with its vaccination program," Winkenwerder said.