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Girl's death after receiving Cervarix illustrates the difficulties of assessing risks of vaccines

September 29, 2009 | 10:56 am


For the record: An earlier version of this story and its headline incorrectly referred to Gardasil. They should have referred to Cervarix, instead.

The death of a 14-year-old British girl hours after she received the Cervarix vaccine that protects against human papilloma virus, the virus that causes cervical cancer, illustrates the problems associated with assessing the risk of vaccines. The problem is particularly acute now because of the unwarranted widespread fears about the supposedly untested vaccine against the pandemic pandemic H1N1 influenza virus.

Though rare, adverse effects can be caused by vaccines, which is why the government has established a program to compensate victims of such events. But adverse events also occur regularly in the absence of vaccination, and the common tendency is to attribute these events to the vaccine, even though there is no physical link. The most common manifestation of this phenomenon involves the people who say the flu vaccine gave them the flu. It didn't. The vaccines contain inactivated viruses that are simply incapable of producing the flu. But a certain percentage of people are going to catch the flu during any given week, and if they catch it before their bodies have had a chance to build up immunity after vaccination, they want to believe the shot caused it.

Health officials are particularly sensitive to the situation among pregnant women, who are at the top of the list for vaccination against swine flu because they have six times the normal risk of developing severe side effects and hospitalization from an infection. Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention, notes that 15% of pregnant women will suffer a miscarriage. If that miscarriage occurs during the few days after a flu shot, many people will assume the shot caused it. The only way to determine whether that is the case is to do a careful study of the miscarriage rate among women who did not get a flu shot and see whether the rate is higher among those who did. Past studies of seasonal flu vaccines have not shown any increase in miscarriages among women receiving the shot, and there is no reason to think that results with the swine flu shot -- which is, for all practical purposes, nearly identical to the seasonal flu vaccine -- will be different. The same with heart attacks, allergic reactions and other problems vaccine skeptics attribute to the shots.

Because of the concerns about the swine flu vaccine, the government is undertaking an unprecedented surveillance program to check for any potential problems, according to the Associated Press. In addition to normal surveillance programs, a team at Harvard is linking insurance company databases to vaccine registries to check for above-normal rates of adverse events. Johns Hopkins researchers are contacting 100,000 vaccine recipients to check on their health status. And the CDC is preparing take-home cards for vaccinees and asking them to report any problems to the agency.

As for the British girl, it is possible that she died from an adverse reaction to the Cervarix shot. But several other girls at the school Natalie Morton attended in Coventry were also sent home because they felt unwell after receiving the vaccine. That suggests that something else in their environment was at fault. But officials have quarantined the batch of vaccine used at the school, and an autopsy is being conducted to determine the cause of death.

-- Thomas H. Maugh II