I understand that vaccines are proven to work and are a great advancement in our medicine, and also that homeopathic remedies don't work, but don't they work on the same principal? Why does one work and the other doesnt?
They do not work on the same principle.
I can see how vaccines look like a "like treats like" situation, but in homeopathy "like treats like" is a kind of magical thinking.
Let's take an example from Chicken Pox, a virus for which there is an effective vaccine and for which there is a common homeopathic treatment.
Chicken pox infects people once, and it is extremely rare to get a second case because once you have had it, your body forms persistent antibodies against the varicella-zoster virus. When I was a kid, they didn't have a vaccine for this, so kids mostly got chicken pox once and it ran around whole schools and that was it. It's a virus that is fairly minor in children, though it can cause dangerously high fevers. Adults who get chicken pox typically get much sicker than children who get it, and it can lead to permanent harms like infertility in adults who get it. Because it can be so dangerous, we don't want people to risk getting it, so we vaccinate.
The way the vaccine works is that it takes a weakened form of the virus and introduces that into the body of a person with a healthy immune system. The immune system responds and the person who got the vaccine may get some minor symptoms, like a headache or a slight fever, but it will be nowhere near as severe as getting actual chicken pox would be. Because the immune system was exposed to the virus and responded, it now has antibodies against the virus that recognize the virus and respond immediately before it can start replicating in the body. If a person who has either previously had chicken pox or who has been vaccinated against it is exposed to the chicken pox virus, their body uses those antibodies to react to the virus and protect against a systemic infection.
Are you familiar with Star Trek? It's kind of like the Borg. You can't use the same attack pattern against the Borg multiple times because if you do, they'll recognize the pattern and will be able to defend against it. The virus is the attacker, and your immune system is the Borg. It knows what it's looking for and won't let anything get through its defenses.
Homeopathic remedies don't seek to prevent illness or provoke an immune response, they seek to cancel out something that is happening in the body.
For chicken pox, which produces itchy red bumps, homeopaths use Rhus Tox - a dilution of poison ivy, a plant that causes itchy red bumps if you encounter it in nature. The Rhus Tox didn't cause the chicken pox, it's not given to prevent the virus, it's from a plant that is completely unrelated to the virus that happens to produce some of the same symptoms as the virus when you touch it.
They don't even think that the Rhus Tox will provoke an immune response from your body like actually touching poison ivy would, they're attempting to use an unrelated compound (that is so diluted that it isn't even present in the preparation) in place of your immune system to attack the itchy red bumps.
So I'm going to go over this in a few brief points:
Vaccines are preventative ONLY, they are not a treatment for illness or symptoms of an illness
Vaccines work by introducing your immune system to a partial, weakened, or dead virus so that your immune system can form antibodies against that virus and prevent that virus from replicating in your body when it is later exposed to a whole/strong/live virus.
Different vaccines have different levels of effectiveness and produce different lengths of immunity; this is for a number of reasons, but if you get a measles shot as a kid you may only ever need one booster, while you need a flu shot every year and a tetanus shot every decade. All of them work the same way, though: they show your immune system what a virus looks like so that your immune system can kill the virus.
That is why immune compromised people sometimes can't be vaccinated, or why vaccines don't work as well for them or may need higher doses or more boosters. Because they don't have a healthy immune system, weakened viruses like the ones in the chickenpox virus might be too strong for their immune system to fight, and even if it doesn't get them sick, their bodies may not be able to produce enough effective antibodies to protect them from the virus in the future. That's part of why it's important for as many people to be vaccinated as possible; the more people who are vaccinated, the harder it is for viruses to spread, and vulnerable people like immune compromised people or babies too young for vaccination won't be exposed to deadly viruses.
Homeopathy, on the other hand, aims to treat symptoms of an illness that a person is already experiencing.
Homeopathic treatments do not aim to provoke an immune response, they aim to cancel out a symptom with a cure.
Dilution is a very important part of homeopathy, with homeopaths claiming that the more diluted a preparation is the stronger it is. This is simply incorrect; I don't know how to make a more logical explanation of that, it is just wrong that less of a substance causes more of a response.
Homeopathy says "like treats like" and that may seem like using a vaccine with a weak virus to prevent infection from a strong virus, but their version of "like" is different - Rhus Tox (poison ivy) is supposed to be "like" chicken pox because both cause itching. Rhus tox is also supposed to treat PCOS, erectile dysfunction, uterine prolapse, sunken eyes, nausea, and backache. "Like" can have an extremely broad meaning in homeopathy, which should be cause for suspicion.
Here's a paper that compared the immune response of college students given homeopathic "vaccines" against a control group and against a group of students who were given standard medical vaccines. The control group and the homeopathic group both did not have an immune response in titer tests, while the vaccination group did have an immune response, demonstrating that they had protection from the vaccinated viruses. It's a pretty good demonstration both of how effective homeopathy is (not at all) as well as how to set up a fair and ethical study to look at the effectiveness of different kinds of treatments.
