What are they, and how are they saving lives? Vaccines What are they, and how are they saving lives?

*This is NOT specific to viruses- there are bacterial vaccines too! What is a Vaccine? A means of producing immunity against pathogens by the introduction of live, killed, or altered antigens (foreign objects) that stimulate the body to produce antibodies against more dangerous forms *This is NOT specific to viruses- there are bacterial vaccines too!

History of Vaccines: 1796 Edward Jenner- vaccine against small pox 1885 Louis Pasteur- vaccine for rabies 1952 Jonas Saulk- Polio Vaccine (Pitt!)

Routine Vaccinations Protect against Serious Diseases. Rubella (german measles) Mumps Polio Pertussis (whooping cough) Measles Diphtheria Tetanus Haemophilus influenzae type b (Hib) Hepatitis B Varicella (chickenpox) Pneumococcal disease Influenza (flu)

Types of Vaccines 1. Inactivated (“Killed”) Vaccines: the virus is inactivated (meaning its DNA or RNA is destroyed) under controlled conditions using chemicals, heat or UV light examples: Inactivated polio, inactivated influenza, cholera, bubonic plague How is it done?- cultivate the microoranism in a tissue culture, multiply, subject to chemical or physical agent to inactivate. Although inactive, still able to stimulate antibodies.

Pluses and Minuses? 1. “Safer” than a “live” vaccine 2. Less potent- will need booster shots to amplify the immune response

2. “Live” Attenuated Vaccines- A vaccine prepared from live microorganisms or viruses cultured under adverse conditions leading to loss of their virulence but retention of their ability to induce protective immunity. (Their virulent properties are disabled)

Pluses and Minuses? 1. Works very well, strong, long-lasting immunity (preferred for healthy adults) 2. Chance of getting mild form of the infection Examples: small pox, oral polio, MMR, chicken pox, yellow fever, TB

3. Toxoid Vaccines Toxoid vaccines are made by treating toxins (or poisons) produced by bacteria with heat or chemicals to destroy their ability to cause illness. Even though toxoids do not cause disease, they stimulate the body to produce protective immunity just like the bacteria’s natural toxins. Examples: Tetanus and Diptheria

4. Component Vaccines Some vaccines are made by using only parts of the viruses or bacteria. These vaccines cannot cause disease, but they can stimulate the body to produce an immune response that protects against infection with the whole germ. Examples: Haemophilus influenzae type b (Hib), Hepatitis B, Hepatitis A, Pneumoccocal conjugate vaccine

Why do Some Vaccines Last a Lifetime and others not?? Depends on the type of virus: i.e. Flu DNA virus vs. RNA virus The RNA virus- no double helix so more unstable. DNA viruses fix their own mutations, but RNA viruses do not have the ability to fix their genetic mistakes, so mutations are much more common. The flu virus is able to mutate- only slight or radical; can give you partial immunity or if there is a SHIFT= major epidemics and our bodies do not recognize it at all

therefore more unstable than DNA. RNA also does RNA: single stranded, therefore more unstable than DNA. RNA also does not have the enzymes DNA does to “check and repair” mistakes in the code! DNA RNA

Some Concerned Parents Have Wondered about These Five Vaccine Issues. The use of thimerosal (ethylmercury) as an additive in vaccines An unsubstantiated link between the MMR vaccine (combination for measles, mumps, and rubella) and autism The necessity of vaccinating children against hepatitis B Pneumococcal conjugate (a new vaccine to protect against meningitis) The relative danger of varicella (chickenpox) THE FOLLOWING INFORMTAION IS FROM THE CDC WEBSITE: (www.cdc.gov)

Thimerosal Thimerosal is preservative which contains a form of mercury (ethylmercury). Thimerosal was used in very small amounts for over 50 years as a preservative in some vaccines. Thimerosal was originally added to multi-dose vials of vaccines. It protected these vaccines from bacterial contamination. Mercury can have toxic effects in large amounts. However, there’s no evidence that the tiny amounts of thimerosal in vaccines has ever caused problems for infants receiving these vaccines. Today, with the exception of some flu vaccines, none of the vaccines used in the U.S. to protect preschool-aged children against 12 infectious diseases contain thimerosal as a preservative.

Thimerosal Scientists and doctors understand the concerns some parents have about preservatives and additives in vaccines. The medical and scientific communities are committed to ensuring the safety of vaccines. Even though there is no convincing evidence of any harm, in June, 2000, the Advisory Committee on Immunization Practices (ACIP) issued a statement saying thimerosal should be removed from vaccines as soon as possible. CDC is working with vaccine manufacturers to remove thimerosal from vaccines as part of a nationwide effort to reduce the amount of mercury children are exposed to, including mercury in food and medicines.

MMR Vaccine: Is It Really a Factor in Autism? Some parents and others have expressed concern about a possible link between the MMR (measles, mumps, rubella) vaccine and the development of autism in children because: MMR vaccine is first given at age 12 to 15 months. The first signs of autism (poor social interaction and speech, repetitive behaviors) often appear between 12 to 18 months of age. 12 months 15 months MMR vaccine first given 0 months Birth First signs of autism

Images of Autism

Independent Studies Have Found No Link between Autism and MMR. A United States study by Dr. Loring Dales showed that the number of autism cases in young children increased even when the number of MMR vaccines decreased over the same time period! A British study by Dr. Brent Taylor showed that the number of diagnosed autism cases did not increase after the MMR vaccine was introduced in 1988. If a link between the MMR vaccine and autism did exist, the number of autism cases would increase or decrease over time as the number of children immunized with MMR increased or decreased over the same time. No study has shown this trend. Additional well-designed studies in the United States and in Europe have found no association between the MMR vaccination and autism.

Vaccines and Autism? Vaccines fueling autism epidemic? Report: U.S. infants exposed to mercury beyond EPA, FDA limits “The mother of an autistic child wonders aloud when health officials will wake up to the epidemic that has claimed not only her son but hundreds of thousands of other children in the United States, with no end in sight. She muses, "Maybe someday this will be as important as SARS and we'll get the same attention. God knows we need it."

The Other Side: Thousands of parents believe that the MMR vaccine has contributed to their children’s autism. They have pictures and videos to prove the ‘before’ and ‘after.’ They speak of the MMR being the only new event in their child’s life in that period between normal development and autistic regression. They point out their children’s marked immune system dysfunction, something with which they were not born. These parents certainly did not acquire their conviction from reading about the twelve cases reported in Dr. Wakefield’s first paper. Nor would they simply be looking for a scapegoat. Please remember, and always remember, their children were normal and their disease is acquired.

“All mass vaccination campaigns result in casualties because every vaccine, like every drug, carries an inherent risk of injury or death. Some individuals are genetically or biologically more vulnerable to vaccine reactions than others, but there are few reliable biomarkers to predict who they are, which is why legally protecting the informed consent rights of all citizens becomes a moral imperative.”

Why Vaccinate Children for Hepatitis B? Hepatitis B is a disease of the liver that can be transmitted in the following ways: Through contact with the blood or other bodily fluids of an infected person Through unprotected sexual contact with an infected person During birth, when the virus passes from an infected mother to her baby Because of common scrapes, falls, and lack of personal hygiene, children (particularly in daycare settings) are more exposed to bodily fluids than you may think.

Pneumococcal Conjugate Vaccine Pneumococcal conjugate vaccine was licensed in 2000. The fact is, work on finding a vaccine started all the way back in 1911. That’s proof that vaccines can sometimes take decades to develop. Scientists kept working because pneumococcus bacteria causes about 1 in 5 cases of bacterial meningitis in the United States and is the leading cause of bacterial meningitis in children.

Varicella (Chickenpox): Not a “Harmless” Childhood Disease Many people believe chickenpox is a harmless illness. In 1999, an average of one child a week died in the United States from complications of chickenpox. These complications include encephalitis, a brain infection; severe staph and strep secondary infections (flesh-eating strep and toxic shock syndrome); hepatitis; and pneumonia.

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NOVA | Killer Disease on Campus | Making Vaccines | PBS