Vaccines are unnecessarily political. There is, first, the targeted campaign of misinformation that leads many to avoid vaccines for their children, and has created a very real scare among well-meaning but misguided parents. At the same time, vaccines are preventative medicine, meaning that you are by definition giving it to people who do not yet have the disease. This will immediately arouse suspicion among fiscal conservatives who don’t want to waste finite funding on unnecessary procedures, and of the social conservatives who don’t like the sanitation of potentially disease-spreading activities like sex.

But, at the end of the day, vaccines simply save many, many lives. The efficacy of any one vaccine will come down to the specifics of the disease and vaccine in question, but the overall effect is undeniable. Vaccines have all but wiped polio from the face of the Earth; they are the only thing that kept ebola from running even more rampant than it did in the most recent African outbreak. In the Western word, they’ve turned otherwise common diseases like the measles into symptoms of poorly educated, and thus poorly vaccinated, fringe communities.

Yet vaccination is a more complex topic than many people realize.

Most people know that vaccines work by stimulating the natural immune response, priming the body to defend itself against a particular invader. It does this by stimulating the release of antibodies, specific defense molecules used to tag and destroy invaders; the body has too many specific antibodies to be making large quantities of all of them all the time, and so it only starts producing most antibodies when it detects the need for any particular one. By then, though, it’s sometimes too late to stop the spread of the infection — and so, with vaccines, we can provide a false alarm that makes sure the body will be ready when and if the real invasion comes.

You’ll often hear that a vaccine is just a very low dose of the disease itself — but that’s only sometimes true. In reality, there are two basic types of vaccine: live and dead. As the name implies, a dead vaccine is one in which the virus particles have been broken apart in a blender — you get an injection of viral shrapnel left over after physicians shatter them to pieces. The proteins on the exterior of the virus can still activate the needed antibody pathways, can still act as a false alarm for your immune system.

Dead vaccines are not as effective as live vaccines, but they also can’t cause disease themselves. For the vast majority of applications in the West, dead vaccines are the preferred option. However, when the risks for a disease are great enough, and in particular the risk of spread of the infection is great enough, a live vaccine becomes the most effective option. Live vaccines are literal injections of the disease, and will always cause some predictable number of cases on its own — but it will also prevent a much larger number of cases, saving more lives in the aggregate than a less effective and less toxic dead vaccine. And vaccine-induced illness is easy to catch and treat, so those who do get the disease are less likely to suffer major consequences.

Additionally, not all vaccines for the same disease are created equal. Some vaccines work with helper chemicals called adjuvants, which help to set up the immune system to respond to the viral particles. These can make vaccines more effective or fast-acting, or simply make a sample of viral proteins go further and vaccinate more people. Adjuvants are often blamed for the alleged adverse health effects of vaccines, and adjuvanted vaccines are often not approved by health authorities in various countries.

Many vaccines also include tertiary chemicals to assist the vaccine in other ways; the mercury-based preservative thiomersal was one prime scapegoat for the early anti-vaccine crowd, as it was incorrectly said to cause autism in children.

The unquestionable efficacy of vaccines isn’t to say that they are incapable of causing harm; anything you put in the body can have adverse effects, especially in a small minority of people. ExtremeTech recently reported on a study arguing for a well supported link between an H1N1 flu vaccine and incurable narcolepsy. The adjuvant in the vaccine seems not to be the cause of the problem, however, as it seems that one of the antibodies stimulated by the vaccine may be mistakenly attacking a portion of the brain related to sleep control.

There are also often legitimate concerns about individual vaccines — that they might cause unnecessary or unacceptable negative side-effects, or address a disease too uncommon to justify the expense. However, the overall effectiveness of vaccination is undeniable. The big technological problems for vaccination around the world, especially in poor areas with sporadic access to power and refrigeration, are practical ones: how do we keep vaccines viable in the African sun, long enough to distribute to potentially millions of people?

The answer lies in both technology and social work. Bill Gates’ charitable foundation has helped pioneer advanced coolers to keep vaccines viable even in areas with no electricity. It’s partly about things like that, but also about education campaigns. The recent spread of Ebola, and the continuing existence of polio, are both due mostly to either lack of urgency to get vaccinated or an active resistance to the practice. With a willingness to accept modern science in the form of newer and better vaccines, some of the oldest and most deadly diseases could be tackled quite effectively.

And for those in the developed world, there’s just no reason to reject one of the core technologies that has allowed our societies to progress as far as they have.

By M.Shahzad Javaid Mughal