Many pregnant women vaccinated against smallpox

ATLANTA — Dozens of pregnant women in the United States have been vaccinated against the deadly smallpox virus despite warnings that doing so could harm their foetuses, federal health officials have said.

The discovery, which was published in a report by the US Centres for Disease Control and Prevention, adds to concerns about the safety of a US campaign to inoculate thousands of soldiers and front-line health-care workers against smallpox.

The CDC said 64 female soldiers, health care workers and women participating in clinical studies were believed to have been pregnant when they received the smallpox vaccine between December 13, 2002 and April 24, 2003.

Another 39 women conceived within four weeks of getting the shot, according to the Atlanta-based agency, which is heading the civilian vaccination campaign. Soldiers were vaccinated under a separate programme administered by the Department of Defence.

Military and civilian authorities had been advised to exclude pregnant women or those who planned to get pregnant within four weeks of vaccination from the campaign because of the risk of foetal vaccinia, a rare infection that can kill the foetus or cause premature birth.

The US military and federal and state health officials are trying to determine how pregnant women slipped through screening. It was not immediately known how many women got the shot as part of clinical studies but 52,185 military women and 6,174 female health-care workers of reproductive age were vaccinated.

CDC officials noted that the pregnancy tests administered prior to a smallpox vaccination might not be effective in the first few weeks of pregnancy. “There is this window where nobody would realise they’re pregnant,” said Dr Jane Seward, chief of the CDC’s viral vaccine preventable diseases branch. “Some (of the cases) are just unavoidable for that reason.”

Seward said that expectant mothers exposed to the smallpox vaccine should not terminate their pregnancies since the risk of foetal vaccinia was so low. Before routine vaccinations for smallpox ended in 1972, just 50 cases, including three in the United States, were reported. No cases have been reported in the past year in the United States. The United States decided to resume smallpox vaccinations for select groups last year as fears grew that the virus could be used as a weapon by radical groups or countries like Iraq.

Smallpox kills about 30 per cent of its victims and scars the remainder for life. It was eradicated in 1979. The current vaccine is made using a live virus related to the smallpox virus. When administered in the past, the vaccine killed up to two out of every million people inoculated and sickened about 52 out of every million. Some of those who became sick suffered severe brain damage. In addition to pregnant women, US health officials had included people with weak immune systems and those with chronic skin diseases among the groups exempted from the smallpox vaccination programme.

Those with a history of heart disease or suffering from three risk factors for heart disease were also recently excluded after two health care workers and a soldier died of heart attacks shortly after being vaccinated. — Reuters