Vaccines: A “shot” at eliminating infections

Source Huffington Post

A highly contagious, airborne, and potentially deadly infection has recently been spreading in the United States at an alarming rate.  Infected people experience coughing, fevers, rashes, muscle pain, sore throat, and other flu like symptoms that can develop into pneumonia. Without a specific treatment, rest and medication can only relieve symptoms. This virus is called measles and can be completely prevented by a simple shot, called a vaccine.

Source: nationalweekender.net

Health officials are urging people to make sure they are up to date on their Measles, Mumps, and Rubella (MMR) vaccine to prevent further measles infection. Recently, there has been an “anti-vaccine” movement for fear of side effects of vaccines, which has been blamed for the decreasing rate of vaccination in the United States and other countries. So exactly what are potential side effects, and how does a vaccine prevent us from contracting viruses?

Vaccines use our immune system to keep us from getting sick

The human immune system is incredibly complex and effective at protecting us from getting fatal illnesses. In essence, it is a military system that defends us from harm in the form of disease caused by bad microbes, more commonly referred to as germs. Specialized cells in our bodies called macrophages make up an army used specifically to fight off bad microbes.

Macrophages recognize that bad microbes have a different structure than regular cells in our bodies. Molecules called antigens mark bad microbes. Molecules in the macrophage called antibodies recognize bad antigens when the macrophage comes across them, and tell it to attack them. The macrophage engulfs the microbe and grinds it into pieces. The figures shown below illustrate this process.

A macrophage preparing to engulf a bacteria 
(Source: Illustration by Pat Britten)

Source: http://www.whfoods.com/

Antigens from the pieces of the microbe are delivered by the macrophage (like the army capturing the enemy) to lymph nodes. The lymph node releases them so other special cells, called lymphocytes, will recognize them (registering the enemy into a system). Lymphocytes memorize the antigens’ structure so that the body can attack the bad microbes again if they ever get back into the immune system. This video goes into more detail about how the immune system works. It’s pretty amazing that our bodies do so much to protect us from getting sick.

Source: Information for The Center for Disease Control and Prevention

Vaccines mimic an infection to elicit an immune response using antigens from a weak or dead virus, which cannot reproduce within the body to cause an infection. Macrophages cannot distinguish between healthy and weak viruses when they attack. As with a normal microbe, the antigens from the virus introduced by the vaccine are taken to the lymphocytes and converted to memory. This way the infection does not spread or cause symptoms, but the antibodies are ready to fight it if a healthy form of the virus is ever introduced. The illustration above shows this process. In other words, vaccinations make you immune to germs without ever getting you sick, pretty cool!

Vaccines benefit more than just the people who get them

Edward Jenner developed vaccines in 1798 with a goal of eliminating smallpox. In 1979, smallpox was successfully completely abolished. Since Jenner’s initial vaccine, they have been continually developed and improved, and have diminished and eliminated several contagious and scary diseases, shown in the table below.

Source: National Institute of Allergy and Infectious Disease

While vaccines’ overall purpose is to improve the quality of health of the population, doing so also benefits the economy. It is cheaper to prevent a disease than it is to treat or cure it. Researchers have estimated that for every dollar invested in vaccination development, $5 are saved in indirect costs and $11 are saved in additional costs to society. These costs can be in the form of tax money, medications, time and pay lost taking a sick day at work, and other related costs.

When a critical amount of people are vaccinated against an illness, the entire group of people are much less likely to get the disease, and vice versa. This phenomenon is called “herd immunity” and is demonstrated from the numbers in the table above. The graphic below demonstrates how herd immunity works.

Unfortunately, certain groups of people are unable to get vaccines because they have compromised immune systems in the form of allergies or immune diseases. Pregnant women, people who have had adverse reactions to previous immunizations, and infants are also not eligible to get some vaccines. This leaves them particularly vulnerable to diseases like the measles. The current outbreak has resulted in the death of several infants who were too young to receive the vaccine.

An increasing amount of people are choosing not to get vaccinated

In 1998 Andrew Wakefield published a paper in Lancet stating his hypothesis that the MMR vaccine lead to symptoms in the digestive system that he associated with autism. The study compared children with autism to those without autism who were all given the MMR vaccine. He found that children with gastrointestinal symptoms, which developed after the vaccine was given, also had autism.

This paper had critical flaws that were exposed by peers in the field and follow up studies. His association with autism and the MMR vaccine are attributed to the fact that MMR is given at an age that is also the age of diagnosis for autism. In addition, he only used vaccinated children, when his comparison should have compared unvaccinated children to vaccinated children. The gastrointestinal symptoms that were described developed after autism was diagnosed, so could be attributed to autism and not the vaccine.

Source: http://briandeer.com/

The scrutiny of Wakefield’s study by other scientists led to an investigation by The British General Medical Council, who eventually charged him with misconduct in his research involving abuse of disabled children, falsification, and conflict of interest. Wakefield was stripped of his medical license and qualifications and his article was retracted.

Since, other scientific studies on autism have only disproven his theory, none have been able to reproduce it. In fact, recent studies have shown that autism is a pre-natal development that shows that cellular changes in the brain during pregnancy are the cause of it. Andrew Wakefield is largely the cause of the anti-vaccine movement we have seen today, which is blamed for the current measles outbreaks.

Vaccines are safe, effective, and economically beneficial

Since Edward Jenner’s development, vaccines have been improved and regulated throughout history. To ensure the safety of vaccines, the development phase is a long process with many guidelines by many private and public agencies. This site describes each of the stages of developing a vaccine.

Parents just want to protect their children from any harm, including autism. Unfortunately, the media and one fraudulent scientist have incorrectly made some believe that vaccinations cause autism. However, not vaccinating is putting more children at risk than ever, including those who do not have the choice to get vaccinated.

Vaccines are an incredible tool that scientists have developed to protect the human population against dangerously powerful microbes. They have been successful since their development and are largely to thank for drastically reducing the amount of disease throughout the world. Do your neighbor a favor and get your shots! Cheers to science for helping create a healthier world for everyone!

Source: giphy

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**Updated formatting and image sources 02/03/2015