Over 200 years after the first successful vaccine was created by an English physician, who discovered that inoculation with the cowpox virus protected against smallpox, vaccines remain one of the top lines of defense in the history of modern medicine, said medical experts.
“I always tell my students that vaccines are an ounce of prevention and a pound of cure,” said Dr. Deborah Fuller, microbiology professor at the University of Washington. “Collectively, I think vaccines have saved more lives than all other medical interventions around, including antibiotics.”
Smallpox, one of the deadliest diseases in history, which killed hundreds of millions of people, was eventually completely eradicated worldwide thanks to the widespread development and distribution of the vaccine, serving as a model “for what vaccines could do,” said Fuller.
Fuller and Dr. Jason Schwartz, associate professor of health policy and the history of medicine at Yale School of Public Health, discussed these and numerous other vaccine facts in their online briefing, presented in partnership with SciLine, “Vaccines and Public Health: Development, Regulation and Safety.”
Another successful example is the measles vaccine, which was introduced in the U.S. in 1963. Before the vaccine, there were approximately 4 million measles cases per year. After the measles vaccine was introduced, reported cases dropped by more than 97% between 1965 and 1968.
“Flash forward to more modern times – when the first COVID-19 vaccine was introduced in December of 2020, there had already been 500,000 hospitalizations and 350,000 deaths in the United States alone,” recounted Fuller. Within two months after the vaccine was released, hospitalizations were reduced by about 50%, and by 2023 it’s estimated that the vaccines prevented over 120,000 deaths and 700,000 hospitalizations, and saved $700 billion in costs.
They both acknowledged that the COVID-19 vaccines were developed swiftly, but Schwartz emphasized that no part of the development or vaccine trial processes was skipped or hastened.
“The key trials that were used to give the initial thumbs up to the COVID vaccines, were every bit as large as any trial that has been used for previously licensed vaccines – and much larger than for most pharmaceuticals – precisely because a larger number of research participants gives us a better sense of their safety,” explained Schwartz.
“Nothing in medicine or in life is free from risks,” he continued, but noted that decades of evidence shows that if an individual is going to experience any adverse medical side effects associated with a vaccine “they’re very rare, and they emerge in the initial days or weeks after a vaccine is administered – they don’t show up for the first time months or years later.”
Several years and billions of doses of COVID-19 vaccines affirm that fact, said Schwartz.
“That’s true for COVID-19 vaccines and it’s true for all recommended vaccines,” he added.
Vaccine Innovations
Vaccine innovations, such as mRNA vaccines – which use a synthetic genetic code to instruct the body’s cells to produce a specific protein, allowing the body to develop immunity without actually being infected – have transformed and accelerated the science of new vaccine development, including the Pfizer and Moderna COVID-19 vaccines, said Fuller.
“Some people think mRNA vaccines seemed to suddenly come out of nowhere, but the reality is that there was already 30 years of research behind them,” she explained. When the COVID-19 pandemic emerged, mRNA technology “was already on the verge of becoming the next generation vaccine.”
Prior to mRNA vaccines, the primary vaccine types were inactivated vaccines, which use a dead pathogen; live attenuated vaccines, which use a weakened virus to stimulate an immune response without causing the disease; and protein vaccines, which use protein fragments of a virus.
Vaccine Skepticism
In recent years declining vaccination rates fueled by growing vaccine skepticism, in particular among many parents fearful of claims about potential adverse health effects – including an alleged link between vaccines and autism spectrum disorder – have contributed to declining vaccination rates and increasing numbers of vaccine-preventable disease outbreaks.
“We’re seeing concerning trends that more families are availing themselves of non-medical exemptions, so vaccination rates are going down” – especially in communities with clusters of families who have chosen not to comply with vaccine requirements, said Schwartz.
“There are some serious diseases that we have very, very effective vaccines for that really quickly become a serious problem when we have lower vaccination rates, like measles, pertussis, influenza, pneumonia, just just to name some of them,” he added.
Many concerns regarding vaccines and autism can be traced back to a since-retracted medical paper published in the 1990s by Andrew Wakefield linking the measles, mumps and rubella (MMR) vaccine to autism, which has since been discredited by dozens of studies, he said.
“There’s just not an evidence base to support that, and the evidence has been very clear for many years about that,” said Schwartz.
Fuller said she believes that much of the existing vaccine skepticism can be attributed in part to the “loss of collective human memory about what things were like before vaccines came out.”
“I think for many people questioning vaccines, [who] weren’t alive back then [during early polio and measles outbreaks] don’t have those memories about what it was like, and don’t know the personal stories of how people were affected,” said Fuller. “I think it’s important … to ensure that we don’t lose that collective memory, that history together as people.”
The recent confirmation of Robert Kennedy, Jr., who has a history of vaccine skepticism, as the new secretary of the U.S. Department of Health and Human Services is potentially concerning regarding the future of vaccine recommendations, regulations and development, said Schwartz.
“It’s hard to overstate how important the Department of Health and Human Services – and by extension, its leader – is in every aspect of the vaccination program,” said Schwartz. “There are lots of things that could be done in terms of research priorities that might change.”
Changes could happen at all levels, including at the National Institutes of Health (NIH), which plays a role in vaccine development and testing; at the Food and Drug Administration, which helps ensure the safety and effectiveness of vaccines; and the Centers for Disease Control and Prevention (CDC), which sets the U.S. adult and childhood immunization schedules based on recommendations from the Advisory Committee on Immunization Practices (ACIP).
“There are far-reaching, direct policy levers that flow back to the secretary of Health and Human Services,” said Schwartz. “The priorities they identify can help to either clarify or add to public understanding and confidence in vaccines … or complicate our vaccination efforts.”