Infectious diseases like chickenpox and measles are much more likely to cause serious health problems than vaccination

In late October 2024, a Facebook post claimed chickenpox and measles aren’t diseases but infections. It argued that while a disease “stays, and frequently can’t be cured”, infections go away, leaving behind “a lifetime of immunity”. In contrast, it added, when you vaccinate you are potentially “causing a disease”.

The post was shared more than 15,000 times. Another iteration of the claim was posted around the same time by an Instagram account, @vaccineriskaware, which has more than 20,000 followers.

The post’s claims were presented as a quote from Sherri Tenpenny, an osteopathic physician who in 2021 was listed as one of the “Disinformation Dozen”. This list, developed by the nonprofit organization Center for Countering Digital Hate, included 12 individuals who produced almost two-thirds of the anti-vaccine content circulating on Facebook and Twitter between 1 February and 16 March 2021.

Although this quote has circulated since at least 2019, we couldn’t determine when and where Tenpenny allegedly made these statements.

But whether or not the quote can indeed be attributed to Tenpenny, its claims imply the common anti-vaccine myth that vaccines carry a much higher risk of serious or long-term problems than the infections they aim to prevent. This is simply not true.

Below, we will analyze this and other important inaccuracies in the post.

Chickenpox and measles are diseases caused by viral infections

The post is right about one thing: infection and disease aren’t the same thing. However, it misrepresents the difference between these two states.

Infection is the process during which a harmful microorganism enters the body and multiplies inside it. When an infection spreads enough to damage cells or body organs, it manifests in certain symptoms that we call disease. In other words, an infection is often the first step to developing an infectious disease, which results from the interaction between the infectious agent—for example, a virus or a bacteria—and the body’s response to it.

The World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) define chickenpox and measles as highly contagious diseases caused by infection with the varicella-zoster virus and the measles virus, respectively. Both diseases are most common in children.

The varicella-zoster virus only infects humans and belongs to the family of herpesviruses. The first infection with this virus causes chickenpox, which manifests as an itchy rash that then develops into small blisters filled with fluid.

The first symptoms of measles resemble those of a common cold. A few days later, a spotty rash appears, usually on the face and behind the ears, spreading later to the rest of the body.

Immunity from infection comes with higher risks than those associated with vaccination

The post conveyed that getting chickenpox and measles is harmless or even beneficial for children because of the “lifetime of immunity” these diseases “leave behind”. This idea appears to appeal to some parents, who choose to deliberately expose their children to these infectious diseases so they develop immunity against them^[1].

But this is a risky practice. Children don’t benefit from infectious diseases, and the CDC “strongly recommends against hosting or participating in these events”.

This is in part because while most cases of chickenpox and measles are mild and resolve in one to two weeks, some children develop serious complications. These include secondary bacterial infections, pneumonia, brain swelling (encephalitis), and bloodstream infections (sepsis), which typically require hospitalization and can lead to death^[2].

Globally, chickenpox and measles are estimated to cause about 4,200 and 140,000 deaths per year, respectively. In fact, measles was one of the ten top causes of death in children less than five years old globally in 2021^[3].

Such cases are, however, uncommon in developed countries. One main reason for this is widespread vaccination.

The vaccines against chickenpox and measles are live, attenuated vaccines. This means they contain a weakened form of the virus that induces an immune response but doesn’t cause illness. The measles vaccine is usually administered in combination with the mumps and rubella vaccines (MMR vaccine). After two doses, the chickenpox and MMR vaccines are over 90% effective at preventing chickenpox and measles.

Decades of use corroborate the safety of chickenpox and measles vaccines. The most common side effects of the chickenpox and MMR vaccines include pain and swelling at the injection site, fever, and mild rash. More serious reactions, such as allergic reactions and seizures, happen rarely.

Because chickenpox and measles vaccines are live vaccines, they aren’t recommended in pregnant women and people with severely weakened immune systems.

The potential risks associated with these vaccines don’t outweigh their benefits. Measles vaccination is estimated to have saved 57 million lives worldwide between 2000 and 2022. Thanks to vaccination, measles was eliminated in the U.S. in 2000, and chickenpox cases in the country have declined by more than 97% since routine chickenpox vaccination in children started in 1995.

In Europe, vaccination also drastically reduced the number of chickenpox and measles cases. However, measles outbreaks in Europe and worldwide are on the rise, generally linked to infections imported from countries with lower vaccine coverage, where measles outbreaks are relatively frequent.

In fact, measles cases are surging globally. Measles is extremely contagious, and protecting a community from outbreaks requires that at least 95% of the population is vaccinated. But in the last few years, vaccination rates in many regions have dropped below the optimal coverage due to factors including vaccine misinformation and disruptions in healthcare during the COVID-19 pandemic. This increases the risk of outbreaks, which spread easily in undervaccinated communities.

The viruses that cause chickenpox and measles can reemerge years after initial infection to cause complications

Sometimes, infections resolve on their own and the virus is completely eliminated from the body. But this isn’t always the case, as with chickenpox and measles.

Getting chickenpox usually provides lifetime immunity against the disease. However, the virus isn’t eliminated from the body but instead remains dormant in the nerve tissues. Many years later, the virus can reactivate and cause a painful skin rash on one side of the body called herpes zoster or shingles. In some people, shingles can lead to serious complications, including extremely painful long-term nerve pain and vision loss if the rash affects the eye.

Everyone who has had chickenpox is at risk of developing shingles, but factors such as old age and a weakened immune system increase the risk. Given how widespread chickenpox was before the introduction of routine vaccination, the CDC estimates that about one in three people in the U.S. will develop shingles in their lifetime.

The measles virus can also remain in the body after a person recovers. About a decade later, the dormant virus may reactivate and cause a progressive disorder of the central nervous system called subacute sclerosing panencephalitis (SSPE). The risk of developing SSPE may be higher if the infection occurred before the age of two. While SSPE is very rare, it is always fatal. The only way to prevent it is by vaccinating against measles.

Contrary to the claim, there are many other examples of viruses that cause chronic infections, including the human immunodeficiency virus (HIV) that causes AIDS, the hepatitis viruses B and C, and the herpes simplex virus 1 and 2 that cause genital herpes, a sexually transmitted infection with no cure.

In addition, some infections can develop into other serious chronic diseases, notably cancer. Some examples are the hepatitis B and C viruses (responsible for roughly 70% of liver cancers)^[4], the human papillomavirus (which causes most cases of cervical, anal, throat, penile, vaginal, and vulvar cancer), and Helicobacter pylori (associated with stomach cancer).

These examples illustrate how vaccinating against infectious diseases provides benefits that go far beyond preventing the diseases themselves.

Conclusion

The idea that getting infectious diseases is a healthy way of acquiring immunity is inaccurate and misleading. While diseases like chickenpox and measles are usually mild and resolve relatively quickly, some children develop serious or fatal complications.

Recovering from chickenpox and measles usually provides lifetime immunity against the virus. However, vaccination confers protection in a safer way because it doesn’t expose the person to the disease. It also reduces the likelihood of severe disease and transmission of the infection to others. Children are much less likely to develop health problems from vaccination than from these diseases themselves, a risk that can persist for years even after a person has recovered from the initial infection.

REFERENCES

• 1 – Yang (2020) Transmission dynamics of and insights from the 2018–2019 measles outbreak in New York City: A modeling study. Science Advances.
• 2 – Shah et al. (2023) Global Prevalence of Varicella-Associated Complications: A Systematic Review and Meta-Analysis. Infectious Diseases and Therapy.
• 3 – Villavicencio et al. (2024) Global, regional, and national causes of death in children and adolescents younger than 20 years: an open data portal with estimates for 2000–21. The Lancet Global Health.
• 4 – Maucort-Boulch et al. (2018) Fraction and incidence of liver cancer attributable to hepatitis B and C viruses worldwide. International Journal of Cancer.