Federal officials are investigating whether the smallpox vaccine contributed to the heart attack death of a Maryland woman and brought on heart problems in six others.
The vaccination has never been associated with heart problems before, but health officials are recommending that people with a history of heart trouble refrain from being vaccinated while authorities investigate a possible link.
“It’s a balance, and I think we want to err on the side of safety,” Dr. Julie L. Gerberding, director of the Centers of Disease Control and Prevention, said yesterday.
Three of the seven people under scrutiny suffered heart attacks, including the Maryland woman who died, another woman who is on life support and a third woman who was hospitalized and released. All three were health care or public health workers in their 50s.
Two other people developed angina, or chest pain.
All five of these patients had risk factors for heart disease before the vaccination, such as diabetes, obesity, hypertension or use of tobacco, Gerberding said.
The other two patients under scrutiny suffered from heart inflammation, which is not associated with those risk factors.
Gerberding said she does not expect to find a link between the heart trouble and the vaccine but wants further study before ruling it out.
Based on historical data, a small number of people who receive smallpox vaccinations will die and a few will develop life-threatening complications.
Those complications have never included heart problems, but the data were gathered during a time when most people being vaccinated were young children who were not likely to have heart trouble, Gerberding noted.
The CDC planned to gather cardiac experts today to consider whether something in the vaccine might be triggering heart problems in people who have risk factors.
Health officials also plan to compare the rate of heart problems in the pool of smallpox vaccine recipients with the rate expected in a similar population of people who have not been vaccinated.
Under the new temporary guidelines, people who have been diagnosed with serious heart disease are being told not to get the vaccine. The change was ordered by Health and Human Services Secretary Tommy G. Thompson.
Gerberding emphasized that the program must move forward as the nation prepares for the possibility that smallpox could be used as a bioterror weapon.
“The potential for terrorism has probably never been higher,” she said. “We must continue to be prepared.”
The woman who died worked at Peninsula Regional Medical Center in Salisbury, Md., according to Paul E. Schurick, a spokesman for Gov. Robert L. Ehrlich Jr. She was vaccinated March 18. She died Sunday in Arlington, Va., according to Karen Black of the Maryland Department of Health and Mental Hygiene.
An autopsy performed yesterday at the medical examiner’s office in Fairfax, Va., showed the woman died of a heart attack, said Lucy Caldwell, a spokeswoman for the Virginia Department of Health.
Her death could be the first associated with either the civilian vaccination program that began two months ago or the military program launched in December.
As of March 14, states had vaccinated 21,698 civilians, mostly in public health departments and hospitals. Concerns about the vaccine’s risk have helped keep the numbers well below the 450,000 initially expected.
The military program, where vaccinations are mandatory, has vaccinated “well over” 100,000 soldiers, the Pentagon said.
Based on studies in the late 1960s, experts estimate that one or two people out of every million being vaccinated for the first time will die. The death rate for those being revaccinated was lower: Two people died out of 8.5 million who were revaccinated in a 1968 study.
Additionally, 14 to 52 people out of every million being vaccinated for the first time are expected to suffer life-threatening side effects.
That’s because the smallpox vaccine is made with a live virus called vaccinia, a cousin to smallpox that can cause illness if it escapes the inoculation site and infects another part of the body.
The question now, Gerberding said, is whether the viral infection caused by the vaccine is exacerbating pre-existing heart conditions.
The last U.S. case of smallpox was in 1949, and routine vaccinations against the disease ended here in 1972, as the disease was on the wane globally.