Comment Re:Yes, and it's "viruses," not "virii." (Score 2) 246
Of course evolution happens when selective pressures are significant enough to kill off most of the viral types that aren't specifically resistant. But the belief that the Red Queen's race (that we're caught in a cycle of developing drugs that only give rise to new resistant strains which then require new drugs, etc.) is inevitable is a little naive.
One of the problems with early HIV drug therapy (specifically straight forward azt treatment) was that only a single piece of the virus was targeted. It was relatively easy for the virus to find the mutation that blocked a single drug. The more recent approach has been to use multiple drugs at once (the triple cocktail, HAART) because its significantly harder for the viral population to find a set of mutations to develop resistance to multiple drugs at once.
Similarly, the major problem with antimalarial drugs is that people don't often take them for the full length of time that they're prescribed. The result is that the infection isn't entirely destroyed and returns, but with a higher proportion of slightly resistant variants. When this happens through a series of hosts, the ultimate result is a fully resistant strain (which is why neither mefloquine nor chloroquine will help you in much of Thailand).
Both of these considerations are important with regard to this antiviral. A viral species can indeed be wiped out by drug therapy, just as smallpox was wiped out by vaccination. But when a drug is so frequently prescribed for so many afflictions (which will no doubt be the case with this one), there's little chance that it will remain effective for long. It's unclear whether resistant viruses will be more or less virulent then the current strains, but the people who need these drugs (immuosuppressed patients) will be the ones who lose out.
With well researched and controlled treatment, this could be a very beneficial treatment and could, for instance, rid ourselves of rhinovirus. But that's not likely.
One of the problems with early HIV drug therapy (specifically straight forward azt treatment) was that only a single piece of the virus was targeted. It was relatively easy for the virus to find the mutation that blocked a single drug. The more recent approach has been to use multiple drugs at once (the triple cocktail, HAART) because its significantly harder for the viral population to find a set of mutations to develop resistance to multiple drugs at once.
Similarly, the major problem with antimalarial drugs is that people don't often take them for the full length of time that they're prescribed. The result is that the infection isn't entirely destroyed and returns, but with a higher proportion of slightly resistant variants. When this happens through a series of hosts, the ultimate result is a fully resistant strain (which is why neither mefloquine nor chloroquine will help you in much of Thailand).
Both of these considerations are important with regard to this antiviral. A viral species can indeed be wiped out by drug therapy, just as smallpox was wiped out by vaccination. But when a drug is so frequently prescribed for so many afflictions (which will no doubt be the case with this one), there's little chance that it will remain effective for long. It's unclear whether resistant viruses will be more or less virulent then the current strains, but the people who need these drugs (immuosuppressed patients) will be the ones who lose out.
With well researched and controlled treatment, this could be a very beneficial treatment and could, for instance, rid ourselves of rhinovirus. But that's not likely.
