By Barry C. Fox, M.D., University of Wisconsin
Many people are concerned about the dangers and side effects of vaccinations. Decades of studies around the world confirm vaccination and immunization are safe and effective. In fact, the bigger threat is in postponing a vaccination because the longer people wait to get vaccinated, the higher the exposure risk of a severe and potentially life-altering illness.
Concerns over Vaccines and Their Ingredients
Certain people claim they are afraid vaccines will cause autism or other disorders because they contain mercury. Coincidentally, autism emerged around the time of vaccinations for one-year-olds, creating confusion and conspiracy theories. Numerous vaccines are administered to babies in the first year when developmental changes occur. If something happens around this time, often the vaccine is blamed.
Certain vaccines contain ingredients like formaldehyde, phenol, or mercury, but only in tiny concentrations—and always below a health threshold. Formaldehyde’s purpose is to kill the vaccine’s viruses, ensuring its safety. Aluminum hydroxide enhances the immune response. And phenol acts as a preservative, which is especially important when vaccines are being sent overseas and need to maintain their stability for longer periods of time.
Thimerosal is a mercury-containing ingredient that was utilized in many vaccines to prevent bacterial growth. It’s no longer used in the United States in any routine childhood vaccines. In fact, no scientific study has ever found a connection between autism and thimerosal in vaccines.
This is a transcript from the video series An Introduction to Infectious Diseases. Watch it now, on Wondrium.
Dr. Wakefield and Fraudulent Vaccine Studies
The largest case-control study of the link between autism and vaccination showed no direct cause-and-effect relationship. This controversy was compounded over the last decade by a researcher named Andrew Wakefield who fraudulently published results in 1998 in Britain’s prestigious medical journal, The Lancet, stating that there was an association between the two.
His original publication included findings with a blatant conflict of interest since the author was being paid by a law firm to publish his paper. Allegedly, the law firm was planning to sue vaccine manufacturers and create a vaccine scare. Dr. Wakefield admitted to the fraud, but the fact that his work had been considered ‘gospel truth’ for years caused significant damage.
Learn more about zoonosis—how diseases are transmitted from animals to humans.
Are Vaccines Made by Live Viruses Secure?
Another concern for some individuals is for vaccines made with live viruses. Is there a chance a person can acquire the disease that the vaccine was meant to protect? It’s true that certain vaccines like varicella or chickenpox can cause mild symptoms of the disease itself because they contain an attenuated form of the live virus.
So, mild pox rashes may occur in about five percent of the vaccinated. Another example is the live oral polio vaccine used before 1998, which contained a live virus, resulting in some cases of actual polio. In the United States, this vaccine has now been replaced by the killed virus. Nevertheless, certain issues remain with live vaccine campaigns worldwide.
Parental Concerns over Vaccination
Some parents feel there are too many vaccines in the first six months. They’re worried this could cause overloads in the immune systems of newborns. The current recommended vaccine schedule can include up to 23 shots by the time children are two years old, and as many as six shots at a single doctor’s visit. So, it’s not surprising that people are concerned.
But doctors believe that children have an enormous capacity to respond safely to challenges to their immune system. For measles, 95 percent of children have to be immunized in order to prevent the disease from spreading, which is a relatively high herd immunity goal.
The consequences of contracting mumps or measles can include impaired fertility due to testicular infection in young men who contract mumps. Approximately one in 20 children who contract measles develop serious viral pneumonia. Measles can also cause encephalitis, inducing permanent brain damage.
Learn more about emerging and reemerging diseases.
Vaccination, Immunization, and Lifetime Protection
Some people say that some vaccines are not 100 percent effective and also don’t give life-long protection, hence, the risk of vaccination outweighs the benefits. Some vaccinations, like chickenpox and hepatitis A, are thought to grant lifetime immunity. It’s true that with other vaccinations, protection may only last 5–10 years. And the flu shot only covers someone for one year since the influenza virus strains are different every year and a new vaccine must be developed.
Part of the decision whether or not to get vaccinated depends on the individual body’s response to illness. The influenza vaccine, however, is sometimes less than 100 percent effective. Depending on age, health, and the strain of the virus that’s circulating, its efficacy is believed to be between 50–90 percent.
The vaccine is usually less effective for older folks and those with compromised immune systems, but the high-strength flu vaccine has already shown promise for improved protection. Also, flu vaccines now contain four strains of the virus, not three.
Learn more about the immune system.
Vaccination requirements are likely to get tougher in the future. Influenza vaccination is already uniformly recommended for all children ages six months and older. Working parents who don’t have their children vaccinated may now be faced with another hurdle: influenza vaccination is now being required for preschool and daycare in most states.
Legislation has just been passed in Congress that would require a physician note for families declining vaccinations. It would need to state that the physician had counseled the parents regarding the consequences of non-vaccination. Many healthcare institutions have made influenza vaccinations a mandatory condition for providing healthcare to the general public.
Common Questions about Vaccination and Immunization: Concerns and Misconceptions
The current newborns’ vaccine schedule includes more than 23 vaccines/shots by the time they are two years old. Some parents are worried this could cause overloads in the immune systems of newborns.
Some vaccinations, like chickenpox, are thought to grant lifetime immunity. However, other vaccinations may give protection for 5–10 years. And the flu shot only covers someone for one year since the influenza virus strains are different every year.
The largest case-control study of the link between autism and vaccination showed no direct cause-and-effect relationship.