|MadSci Network: Immunology|
Well, I hate to put it this way but I think your observation is tainted by what you perceive as common bacterial and viral infections. A normal, healthy immune system overcomes bacterial infections all the time. The common cold, caused by rhinoviruses, is typically resolved quickly. Most people who think they have the flu really have a rhinovirus infection and not influenza. Influenza symptoms, in contrast, typically last two weeks and are typically far more severe than common cold symptoms. Hepatitis viruses, Herpes viruses (including chicken pox), HIV, Human papilloma virus, and many other viruses are examples of viral infections that can last years; for most of those viruses the infection is never resolved and the virus is always present. It may go latent at times but it remains in your body, ready to re-emerge at a later time. I can think of a number of common bacterial infections which can resolve themselves without treatment: Salmonella, Listeria, E. coli, Strep, Staph. Yes, all of these bacteria can be lethal (so can influenza!). But many people every year get infections from eating contaminated food and they do not succumb to the bacteria even without antibiotics. Staph can infect wounds and can be resolved with a little neosporin or betadine. Strep throat is commonly treated with antibiotic but not because you can't get rid of it yourself - the immune response to strep can result in rheumatic fever and damage to the heart, so the antibiotic gets rid of the bacteria before the immune system gets going. The concern with antibiotic resistant bacteria is not with normal healthy people but with hospital patients, many of whom are ill and immunosuppressed and cannot fight off infections that healthy people could fight off easily. Antibody is not less effective for attacking bacteria, in fact it really functions best against bacteria and not against viruses which can hide inside cells. This is why antibody is so ineffective against HIV and why an HIV vaccine has been so difficult to generate. To sum up, you can look at the variety of bacteria and viruses that infect humans and find a wide variety of symptoms and resolutions. I don't think that the immune system is any better (or worse) in general terms of fighting bacteria versus viruses - I think it is far more dependent upon the individual bacteria or virus. One could make a case, though, for the immune system being poorly equipped to handle parasites - amoeba, worms, malaria.
Try the links in the MadSci Library for more information on Immunology.