patrick.net

Those are all good questions Zlxr and a thorough answer would require many links. In brief though, nobody has yet found an upper limit on the number of vaccines a body can tolerate and maintain, and if such a limit exists it is probably very high. The immune system works partly by recognizing disease and destroying it, so the faster it can do that the more likely you are to have immunity or at least recover. For example, the 1918 swine flu pandemic killed 50 million people, with the most likely to die being ages 20-40. Unlike most flu, older people were more likely to be immune or to recover; one likely explanation is they had previously been infected by a similar flu decades before, which left them with some immunity to the 1918 flu. Survivors of the 1918 flu showed immune response to similar virus into their 90s. Over a lifetime, the average person's immune system learns to recognize probably hundreds of different infections, maybe thousands. Like eyesight, the immune system peaks in early childhood, but with experience it learns to recognize much more quickly things it has already seen. This is how immunity has evolved, and Bob is correct when he says around 10% of the human genome consists of leftover viral DNA that infected our ancestors, so infection and immunity are central to evolution and our DNA. BTW 10% is a lot, in fact it's more than the difference between us and monkeys. Vaccines stimulate the immune system, and Bob is correct in describing a basic mechanism. That can confer immunity lasting many years, in some cases (e.g. Hepatitis B) a lifetime. An issue with immunity is, the immune system goes into terminal decline as people age, and diet and some drugs (especially chemotherapy) can weaken it even further, so YMMV. Regarding shingles specifically, a good brief article is available on the Mayo Clinic website.

Regarding Lyme and other disease spread by ticks, you might want to read this:

http://www.msnbc.msn.com/id/41973641/ns/health-infectious_diseases/

and (if you haven't already seen it) you might want to watch this:

http://www.underourskin.com/

One issue with bacterial infections like Lyme is the bacteria can produce neurotoxins that can cause lasting consequences even after the bacteria are gone. Another issue is, the people who get infected once, tend to get infected again (e.g. if their dogs brought ticks into the house last year, they'll probably do the same again this year and next year), so they can develop a series of re-infections adding up to almost a chronic disease.

Some people report improvement with long term use of antibiotics, instead of the short term use that insurance pays for. That might be due to the issue of re-infection, or the anti-inflammatory effects of certain antibiotics (e.g. doxycycline), or other factors. Unfortunately American law prohibits you from buying antibiotics without an Rx, and insurance increases the price dramatically. Many go to Mexico or order online, but Obamacare is increasing enforcement to stop that. Under Our Skin reports evidence that, in the case of Lyme at least, the purpose is to maintain a captive market for treatment modalities that pay more powerful lobbyists.

Much remains unknown, new bacteria and viruses evolve and often don't even get identified until someone recognizes a disease. Instead of a public health system, or a national defense system that includes health, we have a politically driven medical system that maximizes revenues and too often victimizes patients. A coalition of the bribed in the capitol presume to decide what's best for everyone's health, and it seems always to be what's most lucrative for their own patronage networks.

It Causes Tumors in Rats and Is in Your Food