The goal of public health is to prevent disease. In 1800, over 46 percent of children in the U.S. did not survive past age 5 years. By 2020, the percentage plummeted to single digits. The graphics are stunning. Along with improvements in sanitation and hygiene, vaccines have been essential for this achievement.

Gone are the days in which parents lived in fear that their children would die from childhood diseases such as diphtheria, pertussis (whooping cough), tetanus (lockjaw), and polio.

Every summer during the mid-20th century, polio would appear raising so much terror that many parents would flee town with their children, hoping to protect them from permanent disability or death.

The parents of the 21st century have been spared these terrors. Cases and deaths from tetanus, diphtheria, and pertussis have plummeted along with other vaccine-preventable diseases.

Polio cases and deaths have largely vanished except for a few cases in Pakistan, Angola, and Nigeria, according to the Global Polio Eradication Initiative.

Tragically, measles is experiencing a resurgence because of a flawed paper that falsely linked the measles, mumps, rubella (MMR) vaccine to autism. Subsequent misinformation campaigns have resulted in parents refusing to vaccinate their children with the MMR vaccine.

What led to this fiasco?

The Measles, Mumps, Rubella Controversy

In 1998, Andrew Wakefield, a gastrointestinal doctor (GI) working at the Royal Free Hospital in London published a paper in The Lancet, a British medical journal, describing how 8 out of 12 children who received the measles, mumps, rubella (MMR) vaccine had subsequently developed autism, according to their parents. There was no comparison (i.e., control) group of children who had received the vaccine but had not developed autism. The authors themselves stated, "We did not prove an association between measles, mumps, and rubella vaccine and the syndrome described." They stated that they had identified a chronic enterocolitis [i.e., inflammation in the small and large intestines] in the 8 children that may be related to their neuropsychiatric dysfunction. Wakefield was a GI doctor, and the children had been referred to him because of their abdominal pain and diarrhea. [Note: Several studies have found a possible association between the gut microbiome, gut-brain axis, and autism spectrum disorder (ASD). While association does not mean causation, children with ASD have been found to be prone to gastrointestinal disorders.]

Wakefield's MMR vaccine assumption was pure speculation, and the study design flawed, but The Lancet published it anyway. The paper had ethical improprieties beyond its flawed study design.

On February 18, 2004, several allegations of research misconduct were brought to the attention of The Lancet's editors. These allegations included: 1) a lack of ethics approvals for invasive procedures on the children; 2) Wakefield had stated that the children had been referred to him, but instead, he had chosen them to participate, 3) A financial conflict of interest existed between Wakefield and the UK's Legal Aid Board that had been funding the study to support litigation against vaccine manufacturers; 4) Wakefield did not disclose that he had been planning to set up his own vaccine company with one of the study subject's father serving as the managing director.

Twelve years after publishing Wakefield's paper, The Lancet retracted it.

Subsequent large, population-based studies found no relationship between the MMR vaccine and autism. By then, the damage had been done. Public trust in vaccines, particularly the MMR vaccine, was compromised. The repercussions continue with ongoing misinformation campaigns.

Measles Outbreaks in the U.S. and Globally

As of September 24, 2025, measles in the U.S. surpassed 1500 cases according to the CDC. The outbreak originated in West Texas and spread to other states including Arizona and Utah. Unusually high rates of pertussis have been also occurring. So far, no congenital rubella syndrome cases have been reported. Ninety-two percent of the measles cases have been in patients who had not been vaccinated or whose vaccination status was unknown. There have been three confirmed measles deaths.

In 2000, measles had been eliminated in the U.S. because of the herd immunity provided by the MMR vaccine. At least 95 percent of the population must be immune for the measles virus to stop spreading.

In 2023, the global estimated two-dose vaccination rate against measles was only 65.3 percent. There had been progress from 2000-2022 towards global measles eradication, but the Covid-19 pandemic led to a decline in MMR vaccinations, leaving millions of children vulnerable to infection. From 2021-2022, estimated deaths from measles increased 43 percent from 95,000 to 136,000 people globally.

The measles virus causes fevers, cough, conjunctivitis, and a characteristic rash. Complications from measles includes bronchitis, laryngitis, pneumonia, encephalitis, and if the patient is pregnant, fetal loss. Pneumonia and encephalitis are the most common causes of death. The virus may also erase the immune system's memory which means that the patient can get reinfected by microbes that they had previously recovered from.

How Do Vaccines Work?

Educating the public about vaccines and how they work is essential to regaining trust. Vaccines are essentially "target practice" for immune systems. Historically, vaccines have been composed of either killed, deactivated, or parts of microbes such as bacteria and viruses that are given to the body, typically either through oral or dermal administration or intramuscular injection. These components elicit an immune response (i.e., rally the troops). The goal is to prepare the immune system so that when it encounters the actual pathogens, it will be ready to attack. Vaccines don't prevent infection, but they do reduce the risk of severe illness or death from the pathogens that they are designed to mimic.

Since they are meant to elicit an immune response, vaccines can cause side effects. Most are mild. Soreness and swelling can occur at the injection site. Achiness and fatigue can occur because the body thinks that it's fighting an infection, and it wants the person to sleep to allow the immune system to do its work. Serious side effects are rare but can occur such as allergic reactions and seizures. People with compromised immune systems are more vulnerable to severe effects.

Superior Doctors Prevent Disease

An ancient Chinese proverb states that inferior doctors cure disease, mediocre doctors treat impending disease, and superior doctors prevent disease. Benjamin Franklin shared this sentiment. In 1736, he famously said, "An ounce of prevention is worth a pound of cure."

The wisdom of prevention is as true now as it was then.

Preventing disease is far preferable to treating it. In some cases, treating disease is impossible. For example, rabies is virtually 100 percent fatal after symptoms appear. However, if post exposure prophylaxis is promptly given with the rabies vaccine and, if indicated, rabies immunoglobulins, it is 100 percent preventable. Since 99 percent of human rabies is caused by dog bites, vaccinating dogs to prevent human rabies is the ultimate prevention strategy, a classic example of One Health in action.

Veterinary vaccines protect animals' lives. There are important vaccines for dogs and cats and for food producing animals. People want their pets to live long, healthy lives, and nobody wants to consume animal products from sick animals. (Pasteurization is another important food safety strategy, preventing milk pathogens such as bovine tuberculosis from spreading from food animals to humans.)

The Responsibilities of Political Leaders

Political leaders are responsible for protecting and improving the lives of their constituents. Modern medicine relies on safe and effective technologies such as vaccines to save lives.

Political leaders, such as Health and Human Services Secretary (HHS) Robert F. Kennedy Jr., who sow fear about vaccine safety do a tremendous disservice to the public. Florida Governor Ron DeSantis announced that he will end all mandates requiring vaccines for school children and adults. Florida would be the first, and so far, only U.S. state to pass this law. Hopefully, no other state will follow Florida's lead. Otherwise, prudent states and nations seeking to protect their citizenry from vaccine-preventable diseases should require all travelers from Florida to provide proof of vaccination before entry.

Vaccines have been one of the greatest breakthroughs in the history of medicine and public health. According to the World Health Organization, global vaccination efforts over the past 50 years have saved an estimated 154 million lives. Vaccines ensure that most newborns live to adulthood, leading healthy lives. We must make sure that current and future generations receive the life-saving benefits of vaccines.