WHO rät bei HIV-Patienten von TBC-Impfung ab
(ht) Da bei HIV-infizierten Kindern ein stark erhöhtes Nebenwirkungsrisiko besteht, rät das zuständige Gremium der WHO in diesem Fall von einer Impfung gegen Tuberkulose ab. Das Risiko übersteige in diesen Fällen den Nutzen.
When the vaccine causes disease
For infants infected with HIV, risks of vaccination outweigh benefits.
"For decades, the World Health Organization (WHO) has recommended that every newborn at risk of tuberculosis (TB) should be protected with a single dose of the bacille Calmette-Guérin (BCG) vaccine as soon after birth as possible.
But in late November, the WHO's Global Advisory Committee on Vaccine Safety reviewed mounting evidence from Argentina and South Africa and concluded that for infants infected with HIV, the risks of BCG vaccination outweigh the benefits. If you know that a child is infected with HIV, this child should not receive BCG," says Paul-Henri Lambert, the committee's chair.
In rare cases, BCG can itself make children ill, triggering a swelling of the lymph nodes and mimicking the symptoms of TB. In HIV-infected children, the risk of this disease is estimated to be as high as 400 for every 100,000 vaccinated children (Vaccine 25, 14–18; 2006).
"That's a very high risk. In fact, that's about half the incidence of TB in this age group," says William Hanekom, laboratory director of the South African Tuberculosis Vaccine Initiative. And the benefit of BCG vaccination to HIV-infected children is as yet unknown.
Hanekom has just wrapped up a trial to compare the immune effects of BCG vaccination on HIV-infected children with its effects on healthy ones. The results are expected later this year.
The WHO's new policy says that wherever possible, children born to HIV-infected mothers should be tested for HIV—which cannot be done till the infant is at least six weeks old—and only vaccinated if they are uninfected.
Most African countries have the resources neither to test every child nor to make sure that the mothers bring their children back for the vaccine, but may decide to postpone vaccination anyway, Hanekom warns.
"It's a high-risk policy and it may have been done in relative haste," he says. "I think it's going to result in a lot of HIV-negative kids getting TB." - Nature Medicine, doi:10.1038/nm0307-274b