Six die after yellow fever jabs

Sarah Boseley, health editor
Friday July 13, 2001
The Guardian

Scientists have called for an urgent review of the safety of yellow fever vaccine which is routinely given to travellers heading for Africa and South America, following the deaths of six people within days of immunisation.

Millions of people have been vaccinated against the disease with no ill effects. The jab used to be considered one of the safest of the vaccines which are made from a weakened form of the virus itself.

But reports published in this week's Lancet have revealed the deaths of a five-year-old girl and a 22-year-old woman in Brazil, three elderly people in the US and a 56-year-old man in Australia as a result of immunisation. One other man in the US nearly died.

While scientists stressed that travellers must continue to be vaccinated because the disease kills half of those who pick it up, they said that new research is needed to identify why certain people can become sensitised to the vaccine.

Scientists investigating the Brazilian cases said universal vaccination should be stopped with only those in the areas where yellow fever is endemic receiving the jab. Those in the USA said doctors should be careful to give the vaccination only if the traveller is definitely planning to visit a yellow fever zone, particularly if they are elderly.

Two separate papers in the Lancet - on the Brazilian cases and the US cases - and a research letter on the Australian case, identify the vaccine as the cause of death.

The victims all suffered some symptoms of yellow fever, including fever, muscle pain and headache. The elderly Americans, however, rapidly progressed to multisystemic illness, affecting the liver, kidneys, lungs and central nervous system.

The Brazilian team, led by Pedro da Costa Vasconcelos of the world health organisation collaborating centre for reference and research on arbovirus in Belem, Brazil, said that the five-year-old girl and 22-year-old woman suffered fever which progressed to jaundice, kidney failure, low blood pressure and shock. They died around the fifth day after symptoms began.

The scientists said that they could not be certain that some other infection had not contributed to the illness and death. Given that around 2m people received the same vaccine lots, "idiosyncratic host factors" could be to blame. "These serious and hitherto unknown complications of yellow fever vaccination are extremely rare, but the safety [of the vaccine] needs to be reviewed," they wrote.

The four Americans affected, three of whom died, were all vaccinated because they planned to tour what they thought were yellow fever areas. The man who survived was wrongly given the jab before travelling to Nepal and Thailand.

Michael Martin and his colleagues from the national center for infectious diseases in Atlanta, Georgia, said it was possible that age was a factor in the deaths - the American cases were aged from 63 to 79. But the people who died in Brazil were younger, suggesting age was not the only factor.

The cases reported in the Lancet, "along with the growing momentum for mass immunisation in the wake of increased yellow fever activity, underscore the importance of further investigations" into the safety of the vaccine, they said.

The Australian who died had not been outside New South Wales in the 12 months before he became ill but, said Raymond Chan from the South Wales area pathology service in Australia, he died from yellow fever due to infection from the vaccine.

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