New treatment promising against rabies

NEW YORK, Apr 7 (Reuters) After someone is exposed to rabies, they have to be treated quickly with anti-rabies serum, or immune globulin - a scarce commodity. Now, researchers may have come up with an alternative.

Anti-rabies immune globulin is derived from the blood of horses or people who have been infected with the rabies virus, producing antibodies that can be used to neutralize rabies in newly infected people.

The new study, involving experiments in hamsters, shows that a combination of two monoclonal antibodies or MAbs, which can be produced consistently and in relatively large quantities, may be as effective and safe as anti-rabies immune globulin for post-exposure prevention, according to Dutch and US researchers.

Dr Jaap Goudsmit of Crucell Holland BV, Leiden, and colleagues point out in the Journal of Infectious Diseases that the annual death rate from canine rabies is about 55,000. There is a limited supply of anti-rabies immune globulin, which in combination with rabies vaccine is effective in preventing full-blown disease developing after someone has been exposed to the virus.

The researchers have identified a combination of two MAbs, CR57 and CR4098, that show promise as a method of post-exposure prevention. The MAb combination neutralized a panel of 26 subtypes of rabies virus that are common sources of infection.

When administered to hamsters along with the rabies vaccine 24 hours after the animals were exposed to a lethal dose of rabies, the hamsters were protected. The results were comparable to those achieved with human immune globulin, Goudsmit's group reports.

The researchers also note that unlike human immune globulin, production of these MAbs would be consistent from batch to batch and would avoid the risks associated with blood-derived products.

They conclude that the MAb cocktail is a safe and efficacious alternative to anti-rabies immune globulin for rabies post-exposure prevention.

REUTERS KD ND0908