If there’s one thing that anti-vaxxers are sure about it’s that natural immunity is better than vaccine induced immunity.
They’re wrong. Claiming that natural immunity is better than vaccine immunity is like claiming that walking to San Francisco from Boston is better than traveling by airplane. Yes, if you walk you can be sure you won’t be in a plane crash, but the odds are extremely high that you would never get to San Francisco.
[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]Vaccination produces immunity faster and far more safely.[/pullquote]
What’s wrong with natural immunity?
Visit any cemetary from the pre-vaccine age; it’s filled with people who died precisely because natural immunity couldn’t save them. Pre-vaccine cemetaries are filled with people who died of influenza, of diphtheria, of measles, of tetanus, of pertussis. But they’re also filled with people who died simply because they got a minor cut that became infected and, in the absence of antibiotics, the infection continued to spread unimpeded until it entered the bloodstream (sepsis) and killed the unfortunate individual. Natural immunity couldn’t save them.
Consider the Black Death. Literally 2 out of 3 people died because natural immunity could not save them.
Consider the leading causes of death in the US in 1900. Pneumonia and influenza led the list; tuberculosis was second, diarrhea and enteritis were third. Diphtheria was tenth.
Today, pneumonia and tuberculosis can be treated with antibiotics and influenza, infant diarrhea and diphtheria can be prevented by vaccines.
The situation for children was even more dire.
Life expectancy around 1888 was less than 50 years, infant mortality approached 200 per 1000 births, and neonatal mortality was about 50 per 1000 births. The infant mortality rate in 1880 in New York City, a particularly crowded urban area, was as high as 288 per 1000 live-born infants, primarily related to various infectious processes. Infectious diseases such as diarrhea, diphtheria, scarlet fever and tuberculosis dominated as the major causes of morbidity and mortality among children…
But wait, you say: didn’t basic sanitation measure contribute to a decrease in mortality from infectious diseases? Of course they did, but that’s just another acknowledgement that natural immunity was insufficient; preventing exposure in the first place — NOT natural immunity — was the best way to save lives.
Why is vaccine induced immunity so much better than natural immunity? For the same reason that taking a plane to San Francisco is better than walking: it’s faster, safer and far more convenient.
Speed is the key advantage. Individuals who have been vaccinated can produce an immune response much faster than those who must wait for natural immunity to develop.
We’re not born with natural immunity; we make antibodies in response to a threat. For example, we are not born with antibodies to the chickenpox (varicella) virus. When exposed to the varicella virus, though, we can learn to make antibodies to it. It takes time, but gradually we can produce enough antibodies to fend off the disease.
Unfortunately, we don’t always get the time we need. We can make antibodies to smallpox, for example, but many individuals are overwhelmed and killed by the virus long before they could make enough antibodies to fend it off. Those who do win the race and manage to produce enough antibodies to survive are now permanently protected. That’s because the immune system retains the ability to make the specific antibodies against the smallpox virus. Whereas it may take days to produce smallpox antibody when first exposed, a second exposure will be met with rapid and massive production of antibody, generally preventing the individual from getting sick at all.
So for natural immunity to work, you have to get the disease, and you might die before you are able to make enough antibody to protect yourself. What if you could learn to make the protective antibodies without actually getting sick? That’s the theory behind vaccines.
In order to make antibodies to a virus (or bacterium) the body needs to “see” the virus. In other words, it needs to have direct exposure to the virus, but that virus doesn’t have to be functional, and it doesn’t even have to be whole. A virus can be inactivated (live attenuated) or killed and still produce an immune response. It can also be broken down into its constituent parts and the parts can produce an immune response. Any future exposure to the live virus (though contact with others who have the disease) will be met with rapid and massive production of antibody, preventing the individual from getting sick at all. A vaccine is merely an inactivated or dead form of the virus, letting you learn to make antibody without getting sick in the process.
Vaccines do not produce perfect immunity. The dangerous part of the virus might be the part that evokes the most powerful immune response. Rendering the virus harmless by inactivating it, killing it or breaking it up, may remove that part and the immune response to the less dangerous parts might be weaker. So actually getting the disease may produce a better immune response than the vaccine … but ONLY if you survive the disease.
Natural immunity is great in the same way that walking across the country is great. Theoretically everyone could walk across the country, but in reality most people cannot. Theoretically natural immunity can protect people from infectious diseases, but in reality it often cannot. Of course vaccines have risks just like airplane flight has risks, but the risks are minuscule and the benefits are enormous.
Natural immunity is very important, but rather imperfect. Vaccine immunity is better. As with airplane flight vs. walking, you end up in the same place, but you are far more likely to get where you want to be (immune and alive) and you get there much faster.
