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Vaccine Science Related Issues

Vaccines: Are they natural?
Vaccination or immunization
Vaccines and susceptibility to disease
Vaccines and antibiotics
Animals and vaccines
E. Coli outbreaks and food contamination
Questions about vaccine science related issues

Vaccines: Are they natural?

Many of today’s consumers crave organic, all-natural, or free-range products. Willing to pay more and drive further to get these products, they believe they are keeping their families healthy. Some of these same people forego vaccines claiming that they are not natural.

So, what is natural?

According to the Merriam-Webster dictionary, natural means “being in accordance with or determined by nature.” Viruses and bacteria are natural; diseases caused by them are natural.

Because vaccines are made using parts of the viruses and bacteria that cause disease, the ingredient that is the active component of the vaccine that induces immunity is natural. However, critics point to other ingredients in vaccines or the route of administration as being unnatural.

Vaccine ingredients

“Green our vaccines” is a common mantra of those who believe that the ingredients in vaccines are harmful—and unnatural. However, vaccine vials contain well-characterized ingredients in known quantities.

Vaccines contain three types of ingredients other than the virus or bacterium of interest:

Some wonder about the amount of different additives in vaccines or the cumulative effect from several vaccines. This is a valid concern; in fact, the Swiss chemist Paracelsus coined the phrase, “the dose makes the poison.” However, the good news is that the quantities of ingredients in vaccines are determined to be the lowest amounts necessary and when vaccines are given together, they must be studied together. So the quantities of ingredients in vaccines have been determined to be safe.

Route of administration

Viruses and bacteria typically enter the body through our noses or mouths. With the exceptions of the oral rotavirus and intranasal influenza vaccines, most vaccines are given as a shot. While at first glance the injections appear to be different or “unnatural,” they are not when you consider what happens in each case.

When viruses or bacteria enter the body through the nose or mouth, they are detected by cells of the immune system which line the surfaces of these areas of entry. These “foreign invaders” are ingested by immune cells and processed in lymph nodes in the region of the infection. The immune response has two aspects, local and systemic. The immune cells are produced near the site of the infection, but they are dispersed throughout the body via the bloodstream. After the infection has been resolved, a small number of immune memory cells continue circulating to monitor for future infections. Because these memory responses are specific, subsequent exposures to the same virus or bacterium generate a quicker and stronger immune response that completely prevents or significantly lessens the effects and duration of illness.

Vaccines are no different. Although common belief is that vaccines are injected directly into the bloodstream, they are actually administered into muscle or the layer of skin below the dermis where immune cells are produced and circulate as occurs following natural infection.

In conclusion

The active ingredients in vaccines are the parts of the viruses or bacteria to which we make an immune response. The additional ingredients are determined to be the lowest plausible quantities and are studied as part of the vaccine during safety testing. The immune system responds in the same way it would to the virus or bacteria following unexpected introduction. So while not natural in that they are given at specified times, vaccines offer a controlled way to protect ourselves from the viruses or bacteria that cause illness.


Vaccination or immunization

Although we commonly use the words vaccination and immunization interchangeably, they are not exactly the same.

Vaccination was first coined as a term when Edward Jenner used cowpox to immunize people against smallpox. The word vaccination comes from the Latin word vaccinae meaning “of the cow.”

Immunization means immunity induced by a biological agent. The word immunization comes from the Latin word Immunes, referring to “a group of soldiers who once having fought and survived a battle never had to fight again.” In our society immunity has come to mean freedom from anything burdensome; in the case of vaccines, our children are the soldiers, the vaccines are the battle and the freedom gained is from disease.

There are two forms of immunization. Active immunization means administering a vaccine, so that the recipient generates her own immune response. Passive immunization means administering antibodies or antitoxins from another source to protect the recipient. Antibodies passed from mother to child through breast milk are an example of passive immunization.


Vaccines and susceptibility to disease

A study of data from more than 13,000 medical records of young children in Germany showed that when children who received vaccines were compared with those who had not, the vaccinated children were:

Both vaccinated and unvaccinated children had a decreased risk of disease as they got older which makes sense as they would likely be immune to more infections, having developed protection at younger ages. 

Read the full article»


Vaccines and antibiotics

Vaccines and antibiotics are two of the most powerful tools against bacterial infections. Vaccines work by preventing infections whereas antibiotics work by treating them. Antibiotics were first discovered in the early 1900's when a drug called sulfanilamide was found to protect people from fatal bacterial infections such as pneumococcus. Pneumococcus causes pneumonia, bloodstream infections, and meningitis.

Perhaps the most well-known antibiotic is penicillin. By the 1940s penicillin could be produced in large quantities and was recognized as an easy way to save people from disease and death caused by pneumococcus. Doctors believed that they could eliminate pneumococcus with these new tools; thus interest in learning more about preventing pneumococcus by vaccine waned.

Dr. Robert Austrian was a physician who continued studying pneumococcal infections, first in New York and later throughout the country. His studies showed that while people treated with penicillin were less likely to die from their infections, pneumococcus was still infecting as many people as it did before penicillin was available. He also found that people who got the most severe infections with pneumococcus died regardless of whether or not they were treated with antibiotics.  The only way to protect them would be to prevent their infections in the first place; that is, to immunize them.

While Dr. Austrian was completing his studies, people were continuing to be infected and treated for pneumococcal infections using antibiotics, such as penicillin. Antibiotics resolve infections by stopping the bacteria from reproducing themselves.

However, bacteria respond in a "survival of the fittest" manner. These antibiotic-resistant bacteria continue to reproduce and can be passed on to others.

Antibiotic resistance was discovered shortly after penicillin came into popular use. By 1967, pneumococcal strains resistant to penicillin began to appear. At first, the answer to antibiotic resistance was simple. If the bacteria resisted penicillin, use another antibiotic. However, by the 1980s and 1990s, as pneumococcus and other bacteria became more resistant to antibiotics, doctors were running out of options. Indeed, today there are strains of bacteria for which no existing antibiotic will work. Although scientists continue to research, design and test new antibiotics, the process is slow and expensive.

In the case of pneumococcus, we have had some reprieve—Dr. Austrian's first vaccine became available in the late 1970s and a second version, still used for adults today, was introduced in 1983. Although Dr. Austrian's vaccine worked in adults, it did not work well in young children. In 2000, another version that works better in children also became available. As more people in the community are immunized against a particular type of bacteria, such as pneumococcus, there are fewer opportunities for the bacteria to reproduce and infect others. Thus, vaccines have become one of our most important tools in the fight against antibiotic resistance.

To stem resistance, in addition to getting vaccines, people should:


Animals and vaccines

The benefits of vaccines are often discussed as they relate to people. Vaccines keep people healthy, decrease the transmission of diseases throughout the population, and decrease the costs associated with medical care. However, animal vaccines are of benefit to people as well. Obvious benefits include keeping pets healthier and decreasing the costs of veterinary care. But they also decrease the number of human cases of disease by preventing diseases that are transmitted to humans by animals (e.g., rabies). And by keeping farm animals, such as chickens, healthy with immunizations, we can raise more animals and our grocery bills stay lower.

Animal vaccines can prevent human disease

One of the best methods for controlling human rabies in the United States is by immunizing pets. In some other countries where dogs and cats are not routinely immunized against rabies, the animals are the major source of rabies cases in humans. However in the U.S., most exposures occur by inadvertent contact with wildlife. The types of wildlife that account for most exposures in the U.S. vary, depending upon the geographic location. In the eastern part of the country, raccoons account for most human exposures and in the western and central parts of the U.S., skunks are the primary transmitters to humans. Foxes account for most human cases in the northeastern states that border Canada and in Alaska.

Animal vaccines can help the grocery bill

During the 1928 presidential campaign, Republicans promised that a vote for Herbert Hoover would continue the prosperity started by Harding and Coolidge; they promised the proverbial "chicken in every pot." But it wasn't a president who delivered on this promise, it was a scientist. Dr. Maurice Hilleman developed a vaccine that would ultimately decrease the cost of chicken from two dollars to 40 cents and eggs from 50 cents to 5 cents per dozen. The vaccine that Dr. Hilleman developed prevents a disease in chickens called Marek's disease, which causes leg paralysis and cancers of the skin, ovaries, liver, kidneys, heart and spleen of the animals. It is caused by a herpesvirus that spreads easily throughout a flock as well as to neighboring flocks. Prior to the availability of the vaccine, Marek's disease claimed about 20 percent of the chicken population throughout the country.


E. Coli outbreaks and food contamination

In December 2006, 71 people in five states were sickened by lettuce contaminated with E. coli after eating at Taco Bell restaurants in the northeastern region of the U.S. The type of E. coli that caused this outbreak is one of the leading causes of food contamination. Each year approximately 110,000 illnesses and up to 80 deaths in the U.S. result from E. coli infection.

The bacterium typically lives in the intestine of cattle, so a primary source of contamination is undercooked beef. Another common source is leafy vegetables that are not washed well enough or were exposed to raw beef products. Exposure to very small quantities of this bacteria are sufficient to cause illness. Similarly, the illness can be passed on to others without good hand hygiene after using the restroom or changing diapers.

The Taco Bell lettuce outbreak was in the media daily during the outbreak period. During this time, there were probably an additional 5 to 10 times as many cases of E. coli infection throughout the U.S.

Although we only hear about sporadic outbreaks, there are, in fact, E. coli infections that occur every day in the U.S. They are primarily caused by contaminated food or water, but because they affect individuals or a small group, they often go unreported, giving us a false sense that we are safe from these infections.

People sickened by E. coli typically have bloody diarrhea and abdominal cramping with no fever or a low-grade fever. About 8 of every 100 people will also develop a complication that damages the kidneys and could cause blindness or paralysis. Children under 5 years of age and the elderly are particularly susceptible to these complications. About 3 to 5 of every 100 people who suffer complications from E. coli infection will die from them.

Researchers are working to develop a vaccine that will effectively protect against this infection; however, there is still much to be done before a vaccine would become available.

Things that you can do to protect yourself in the absence of a vaccine include: eat only ground beef that has been completely cooked; keep raw meat away from other foods, particularly those that will be eaten raw; drink only pasteurized milk and juices; wash fruits and vegetables thoroughly even those that are labeled as pre-washed; drink tap or bottled water or water that you know has been chemically treated; and avoid swallowing water while swimming.

Finally, wash your hands with soap and water often, particularly after handling uncooked meats, fruits, or vegetables, and after using the restroom.


Questions about vaccine science related issues

Number of vaccines then and now

Q. I recently heard that in the past children were exposed to more in vaccines than they are today. How can this be now that we have so many more vaccines?

A. Science has improved through time, so today’s vaccines only contain those proteins necessary to protect someone from the disease in question. The most dramatic change in this regard was the pertussis vaccine. The first version, called the whole-cell pertussis vaccine, contained about 3,000 proteins whereas the version used today, known as the acellular pertussis vaccine, only contains 2-5 proteins. Learn more»

Protection from breast milk

Q. I heard that breastfeeding will protect my baby from infections, so do I still need to get my baby vaccinated?

A. While breastfeeding may provide short-term protection for your baby, the protection is limited and not specific for most vaccine-preventable diseases. For these reasons, breastfeeding cannot replace the long-term protection your child will develop from vaccination or infection. Since vaccinations are safer than natural infections, babies who are breastfed should still be immunized.

Read more about the difference in immunity from breastfeeding and vaccination in this month’s Trivia Corner»


Updated: February 2013

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