Controversies About Vaccines

Misinformation about vaccine safety has fueled controversies. Research into immunizations shows controversies about vaccines are not based on science and facts.

While social media has become an important part of our lives, one downside is how misinformation about health concerns can spread rapidly online. One of the most troubling examples is the inaccurate, alarmist, and often downright bogus information circulated about the supposed dangers of vaccinations, from childhood vaccines to flu shots and the new COVID-19 vaccines.

Unfortunately, controversies about vaccines do more than increase anxiety and worry. When spurious information feeds controversies about vaccines, people may fear vaccinations and refuse recommended and needed immunizations for themselves or their children. Myths about flu shots, tetanus, pneumonia, and shingles vaccine side effects are also at least partly to blame for many seniors failing to get vaccinations that lower the risk of older adults dying or being hospitalized.

YOU MIGHT ALSO LIKE: How Safe Are Vaccines?

The way vaccines are made and tested has proven, year after year, that immunizations are not only remarkably safe but also help prevent disease and deaths. Still, controversies about vaccines persist and may be increasing. In fact, CNN reported that Francesco Rocca, president of the International Federation of Red Cross and Red Crescent Societies, has warned there’s a growing hesitancy about vaccines around the world.

It is true vaccines can have side effects — although they are usually rare. For example, some people might feel a little tired or run a low-grade fever after a flu shot. There are some potentially serious side effects, including allergic reactions and Guillain-Barré syndrome (a very rare neurological disorder), but these side effects are anything but common.

The best way to set the record straight about vaccines is to see what’s behind the controversies and learn the facts, based on scientific research, about vaccination safety. This is important because, as a team of immunization and infectious disease experts from the Centers from Disease Control and Prevention (CDC) and the Children’s Hospital of Philadelphia pointed out in a review of vaccine controversies published in Clinical Infectious Disease, “concerns about vaccine safety can lead to decreased acceptance of vaccines and resurgence of vaccine-preventable diseases.”

Controversies about the MMR vaccine and autism

Because most children have standard vaccinations early in life and some children later are diagnosed with autism spectrum disorder, anti-vaccination proponents have claimed an unproven cause-and-effect between vaccines and autism. Parents who accept this supposed link may refuse to have their children vaccinated, hoping to protect their offspring from autism.

Anti-vaccination proponents often claim the measles, mumps, and rubella (MMR) vaccine, specifically, causes autism. They may cite a report, published in The Lancet back in 1998, which suggested 12 children with a history of developmental disorders, primarily autism, suffered a worsening of behavior problems after receiving MMR shots.

What’s often not mentioned by those pushing the alleged autism and vaccine link is that the paper was retracted because of the unscientific way youngsters were selected for the small study and the financial conflicts of interest revealed about the authors of the report.

What’s more, in their report on vaccine controversies CDC infectious disease specialist and epidemiologist Frank DeStefano, MD, and colleagues point to numerous studies providing conclusive evidence the MMR vaccine does not cause autism. One review of over 500,000 children born in Denmark between l991 and l998, for example, published in the New England Journal of Medicine, found no association between MMR shots and the development of autism.

What about mercury and aluminum in vaccines?

Vaccines contain preservatives and other additives, and that fact has fueled another controversy — the idea some chemical or metal in vaccinations might be damaging to health.

It is true aluminum salts have been used in vaccines as an adjuvant (an agent to boost the immune response) since the 1930s; the compounds are used in hepatitis A, hepatitis B, diphtheria-tetanus vaccines, HiB (Haemophilus influenzae type B) vaccine, and pneumococcal vaccine. Aluminum is not used in the live, viral vaccines for MMR and rotavirus.

Scientists studied youngsters who received aluminum-containing vaccines and found the children had hair and blood serum levels of aluminum far below the toxic range. A study by Harvard investigators, published in Academic Pediatrics, evaluated blood and hair aluminum levels, vaccination history, and cognitive, language, and motor development scores in 85 children between 9 and 13 months of age. The results showed no correlation at all between the infants’ blood or hair aluminum concentrations and their history of vaccinations. What’s more, there was no link between their vaccine history, their blood aluminum levels, and the children’s overall developmental status.

Thimerosal is a mercury-containing preservative. Because, at high levels, mercury can be neurotoxic, it has caused fears thimerosal might increase the risk of autism. Several studies have looked for potential risks of autism linked to thimerosal-containing vaccines and found none.

However, due to concerns, the Food and Drug Administration conducted an assessment of mercury content in vaccines and found infants up to 6 months of age might be receiving amounts of mercury in vaccines that were higher than EPA (Environmental Protection Agency) recommended safety guidelines for methylmercury.

It’s worth noting, as DeStefano and colleagues point out, thimerosal does not contain methylmercury; it contains ethymercury, which is broken down and urinated out of the body rapidly, so it’s not likely to accumulate in the body. But to be on the safe side, the U.S. has transitioned to childhood vaccines without thimerosal. Now, in the U.S., only multidose vial influenza vaccines contain any thimerosal, and thimerosal-free flu shots are widely available.

More controversies about vaccines: Are too many given too soon?

When your child is born, his or her immune system is not fully developed, putting them at greater risk for infection. Vaccines reduce a child’s work with his or her natural body’s defenses to help develop immunity to disease. If you are a new parent, it’s not surprising you may be surprised when your baby’s pediatrician explains the number of routine childhood immunizations your child needs. In the U.S., babies and toddlers in the first few years of life can receive as many as 26 vaccine injections. Sometimes, as many as five are given at one time. So, parents may worry all these vaccinations so close together might somehow hurt, instead of help, their child’s immune system.

Researchers, however, have looked at this issue and found giving youngsters multiple childhood vaccines doesn’t result in any long-lasting, negative impact on the immune system. No epidemiologic study has found any increase in medical problems or infections related to the number of vaccines or vaccine antigens received in childhood.

In addition, when researchers looked at long-term neuropsychological outcomes in more than 1,000 children over the course of about a decade, they found no association between how many vaccinations were received in infancy and any behavioral or neurological symptoms in youngsters between 7 and 10 years of age. The CDC’s DeStefano has also conducted additional research showing that the age a child is given vaccinations is not associated with an increased risk of autism.

The controversy over a newer vaccine: HPV vaccinations

HPV (human papillomavirus), is the most common sexually transmitted infection. It can cause genital warts and six types of cancer (malignancies of the penis, anus, throat, cervix, vagina and vulva). The HPV vaccine, which now protects against nine strains of HPV, can prevent your child from developing these health problems in later life.

In fact, although the HPV vaccine has been available for only about 12 years, it has resulted in a remarkable decrease in HPV-caused medical problems. HPV infections linked to HPV cancers and genital warts have decreased 86 percent among teen girls. Meanwhile, the percentage of cervical pre-cancers caused by the types of HPV types most often associated with cervical cancer have decreased by 40 percent, according to the CDC.

Despite all this good news, controversies around the HPV vaccine have prevented some youngsters from receiving these vaccinations. Epidemiologist DeStefano and colleagues point to reports of alleged adverse events associated with the vaccine — often erroneously blamed on an autoimmune reaction (when the immune system attacks a person’s own body) — that received widespread media attention. The reports frightened many parents away from having their youngsters vaccinated against HPV.

Extensive monitoring and research, however, both in the U.S. and internationally, has found the HPV vaccine to be safe. One enormous study, conducted in Denmark and Sweden, analyzed the potential effects of almost 700,000 dose of HPV given to young females and found no evidence the vaccine triggered neurological, blood clotting or autoimmune problems. Likewise, another large case-controlled study in France found no increased risk of autoimmune diseases following HPV vaccinations.

Several other conditions (including premature ovarian insufficiency, complex regional pain syndrome, and postural orthostatic tachycardia syndrome), which anti-vaccination proponents have claimed can be caused by the HPV vaccine, have also been studied, but no association with HPV vaccinations has been found.

The vaccine can cause temporary side effects in some young people that can be uncomfortable, including pain or swelling where the shot was given, feeling faint temporarily, a low-grade fever, nausea, headache, or feeling tired.

Bottom line: The CDC emphasizes over 12 years of monitoring and research have shown that HPV vaccination is very safe and effective, and provides long-lasting protection against cancer and genital warts caused by HPV.

Other vaccine controversies: Fact vs fiction

Anti-vaccination controversies have stoked fears that a host of autoimmune diseases, including Lupus, rheumatoid arthritis, and type 1 diabetes could be triggered by vaccinations. Likewise, multiple sclerosis, which is believed to have a potential autoimmune component, has also been added to the list of unfounded vaccine warnings.

To investigate whether vaccines could somehow trigger the body to turn on itself, as some anti-vaccine activists suggest, multiple epidemiologic studies have looked for associations between infant vaccines and type 1 diabetes and associations between vaccines and other autoimmune disease. Two large studies also looked at the possibility vaccines could trigger or worsen multiple sclerosis.

Good news: No association linking vaccines to a host of autoimmune diseases has been found, with one extremely rare possible exception Guillain-Barre syndrome (GBS).

Guillain-Barré syndrome is a rare disorder that follows a viral or bacterial infection and results in the body’s immune system damaging nerve cells, causing muscle weakness and sometimes paralysis. The majority of people who have GBS recover over time.

While its exact cause isn’t understood, in l976 researchers noted a very small increased risk of GBS after people received a special flu vaccine for a potential pandemic strain of what was known as the swine flu. The risk appeared to be real but small — about one case of GBS for every 100,000 persons who received the swine flu shot.

Since that time, multiple studies of GBS after flu shots, and the CDC’s ongoing monitoring of GBS, have found a possible but very tiny risk of GBS from flu vaccine — about 1 to 2 cases of GBS out of a million people who receive the flu vaccine. And here’s the most important fact: You are more likely to develop GBS from getting the flu than after vaccination, the CDC emphasizes.

YOU MIGHT ALSO LIKE: Our Infectious Disease section