ARLINGTON, Va. — The unexpected emergence of heart inflammation among some servicemembers receiving the smallpox vaccine will not deter the Defense Department’s future plans to continue the shots, according to William Winkenwerder Jr., assistant secretary of defense for health affairs.

In a press conference Wednesday, Winkenwerder said 450,293 servicemembers have been inoculated against smallpox since the program began Dec. 13.

Of those recipients, 37 were diagnosed with probable myopericarditis, an inflammation of the muscles surrounding the heart — more than triple the expected rate in non-vaccinated people.

All of those servicemembers are either recovered or recovering, and expect to return to service, said John Grebenstein, deputy director of clinical operations in the Military Vaccine Agency. He and Winkenwerder co-authored a study of DOD’s smallpox inoculation program that was published this week in the Journal of the American Medical Association.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, who was at the press conference with Winkenwerder and Grebenstein, said no one is quite sure why the rate of myopericarditis was so high compared to the rates seen during the smallpox vaccination campaigns of the 1960s.

“That’s something we have to stay tuned for,” Fauci said.

He added, however, that some of the older cases might never have been reported, skewing the data.

The heart issue won’t affect the military vaccine program, Winkenwerder said.

“It will in no way influence our future decisions,” he said.

A deadly, highly contagious viral disease that kills up to 30 percent of those it infects, smallpox “infection has changed the course of war and nations,” Grebenstein said.

After the Sept. 11, 2001, attacks on the United States, the Bush administration decided to inaugurate a large-scale vaccination program directed at military members, health workers, police, firefighters and other likely “first responders.”

Vaccination side effects range from mild itching, headaches, fever and body aches to full-blown rashes over the entire body and, in rare cases, even death.

Sixty percent of the servicemembers who got the shot reported mild itching and redness at the injection site, Grebenstein said. But only about three percent had to take sick leave, missing an average of 1.5 days of work.

Statistics from the 1960s suggested that up to one-third of all recipients would need a week off work after the shot, Grebenstein said.

Current DOD plans call for continuing the present policy of inoculating only those servicemembers who are deploying to “high threat” areas, Winkenwerder said. For example, all members deploying to Iraq must receive the shot.

The smallpox vaccination policy “is under continual review,” Winkenwerder said

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