AIDS researchers debate danger of HIV-2.

AIDS researchers debate danger of HIV-2

A worldwide search to understand theHIV-1 virus responsible for AIDS has left a broad trail for scientists to follow in their study of another virus that also may cause AIDS. First described about a year ago, the so-called HIV-2 virus was discussed this week by an international group of AIDS researchers at the DNA/ Hybridoma Congresses in San Franchisco.

According to Luc Montagnier of theInstitut Pasteur in Paris--who reported the first isolation of an AIDS-related virus (SN: 5/21/83, p.324)--at least two types of AIDS virus do exist. He reports that his group has just completed mapping the entire genome, or genetic material, of an HIV-2 virus, and that they found the HIV-1 and the HIV-2 viruses to be structurally and functionally different. Both, however, are closely related members of the retrovirus class of viruses.

After studying patients from West Africawith HIV-2 infections, Montagnier does not agree with some researchers that HIV-2 is essentially harmless in humans. "Clearly, this virus is also pathogenic in man,' he says. Although found almost exclusively in West Africa, the virus has begun to spread elsewhere. "It could be just a matter of time [before there is an HIV-2 epidemic],' warns Montagnier.

The HIV-1 virus is found among peopleliving in Central Africa, yet it is rare in West Africa. Scientists are mystified as to why two geographic areas so close together harbor different viruses.

If HIV-2 does spread, some scientistssay they are not certain it would pose a real health threat. Robert C. Gallo of the National Institutes of Health, who also isolated an AIDS-related virus, cautions that HIV-2 virus as a cause of AIDS "ought to be looked at a little more carefully.'

Whether or not the HIV-2 virus provesto be a cause of AIDS, researchers have begun studying it in parallel with the HIV-1 virus. Robin Weiss of London's Chester Beatty Cancer Research Institute recently evaluated reactivity between the viruses and antibodies against them. Although his data are preliminary, he says antibodies against HIV-2 apparently neutralize the HIV-1, whereas antibodies against HIV-1 do not similarily affect HIV-2. Weiss told SCIENCE NEWS that this cross-neutralization offers hope that broad-spectrum drugs may be effective against the changeable HIV-1 virus, which, like the influenza virus, is notorious for its rapid mutation rate (SN: 6/28/86, p.410).