Now that scientists can decode the genome of viruses (i think it took about 3 weeks(?) to find the genome of the SARS virus) can antibodies be made to deal with the mutating virus that could be made & changed to keep up with the virus and taken in pill or injection form?
I’m not too well versed on Anti-viral medication, but i thought that was why anti-viral drugs don’t work, because viruses mutate antigens too much for any antibody to work. Can’t scientists overcome this yet?
I’m not just referring to SARS, but all viruses that mutate too fast for drugs to be created that work against them. Can scientists decode a certain strain’s genome, find its antigens, find or create antibodies for each strain of a virus before it mutates?
I asked myself the same thing the other day. I know for a fact they can detect them (that’s how they test for AIDS afair) but to isolate them would be harder, replicating them from a blood sample would probably be impossible with today’s technology and then there is the question of the markers. If a person’s antibodies carry his signature, they would be rejected by the recipients body. Although I don’t think that’s the case. My best guess is that it’s the replication that’s the problem.
Antivirals and vaccines are different things. Just like antibiotics target the parts of the bacteria that are different from humans, antivirals are chemicals which inhibit viral-specific processes.
HIV mutates a lot, and antivirals put a huge selection pressure on it. So we use 3 antivirals to make sure that there is a very very small chance that it can mutate around all three in one go (it is a three-way block). Vaccines are proteins which are either part of a virus (or a whole killed or weakened virus) which trigger your immune system to make antibodies (which bind to the vaccine and the virus) to identify and kill the virus.
Antibodies, either purified ones or recombinantly made ones, are sometimes used as antivirals (or even anticancer drugs). There are a number of diseases where we give IVIG or gammaglobulin injections. These usually aren’t pleasant – it has the consistency of honey.
It is in theory possible to design an antibody very quickly for a mutating virus, especially if one already exists for an older or a variant strain of the virus. The turn around time could be made very short – perhaps on the order of a week or two. Off the top of my head, you could design a set of PCR primers to amplify specific parts of viral proteins that you know are polymorphic. These could then be cloned in a pre-prepared protein expression vector in order to synthesize antibodies. With the proper protein expression system, you could tailor make antibodies and inject them.
This only would give temporary protection – gammaglobulin only gives about 2 weeks of protection and therefore is only used for postexposure prophylaxis and for things like prevention of Hepatitis A before travel. It would also be very expensive.
The better option is rapid vaccine development around parts of the virus that don’t change. The theory is that there are some parts of the virus that it needs in order to function correctly, and therefore can’t be changed. Those are what you target with a vaccine. Indeed, this approach is being tried with HIV, which is amongst the most rapidly changing viruses that we know. Find these parts (which is possible by looking at similar viruses), then design your vaccine to them and go.