6 Real Vaccine Facts Everyone Should Know
Since President Donald Trump tapped Robert F. Kennedy Jr. — an anti-vaccineconspiracy theorist — to lead the U.S. Department of Health and Human Services, vaccines have once again become a prevailing topic among politicians and the general public alike.
Recent health surveys reveal that skepticism toward vaccines, including the COVID-19 shot and annual flu shot, has grown over the past year. Moreover, despite the surge in COVID-19 cases across the United States, recent statistics from the Centers for Disease Control found that only 1 in 10 children and 1 in 5 adults have received the latest COVID-19 booster since its release in August 2024.
“Viruses and bacteria don’t play politics,” Dr. Sarah Sams, a board-certified family physician and board member of the American Academy of Family Physicians, told HuffPost. “They attack anyone and everyone, and by making this a political issue, we’re potentially opening ourselves up to other pandemics, epidemics, [and] resurgence of illnesses that have been really dormant or almost eradicated for years.”
So, what’s the science behind these life-saving medications? HuffPost spoke with medical experts and researchers about vaccine facts that everyone should know, and why staying up to date with immunizations is not only crucial to your health, but to the health of those around you.
1. More than 150 million people worldwide have been saved thanks to vaccines.
According to a 2024 study led by the World Health Organization, an estimated 154 million lives have been saved by global immunization efforts over the past 50 years ― with a majority being infants and children.
“I always like to point out numbers that look at vaccine-preventable illness in the United States as well in the pre-vaccine and vaccine eras,” said Dr. Donald Dumford, an infectious diseases expert at Cleveland Clinic. “The reason we don’t remember how bad diseases such as polio, measles, mumps, whooping cough, tetanus and diphtheria can be is because of the profound effect of vaccines.”
2. Vaccines are rigorously tested before going to the general public.
A common misconception is that the vaccine approval is simple, but in truth, the physician and researcher-led process is extremely rigorous to ensure a vaccine is safe. Sams explained that vaccines undergo several rounds of testing long before ever reaching the general public, and that an “advisory committee on immunization practices reviews all the information and helps develop recommendations for the CDC.”
Typically this involves three phases of clinical trials in which more people are included at each stage to ensure that the vaccine is safe and effective.
Testing and clinical trials do not end after a vaccine has come to market. The Food and Drug Administration continues to monitor manufacturing facilities, as well as the safety, purity and potency of the vaccine.
3. After getting a vaccine, common side effects tend to be mild and serious complications are rare.
Like the overwhelming majority of medications, procedures and medical interventions, vaccines can cause minor side effects; however, these do not outweigh the health issues that skipping your recommended immunizations can lead to.
“Vaccine side effects are generally very mild, and most are associated with the shot itself. For example, having a sore arm after getting a shot is possible, but is not a serious problem,” said Dr. Lisa M. Lee, a professor of population health sciences at Virginia Tech, epidemiologist and former CDC official. “For some vaccines, a handful of people have aches, or a fever for a day or two after getting the shot. This is usually a sign that the person’s immune system has been activated, which is what we want.”
In rare cases, severe health issues such as allergic reactions can occur after getting vaccinated, and you may not be a good candidate for certain immunizations in the future.
4. Experiencing side effects after being immunized does not mean you’ve contracted the virus, and a majority of vaccines do not contain a live virus.
If a vaccine leaves you feeling fatigued, feverish or achy for a couple days, this does not mean you’ve contracted the illness that’s being vaccinated against. As Sams said, when you get vaccinated, you’re receiving “a piece of the code but not the entire viral particle” to strengthen the immune system.
“Some types of vaccines contain small parts of the disease-causing virus or a virus that is weakened or deactivated, but these parts or deactivated viruses cannot cause the disease,” Lee explained. “They are used to trick the immune system into developing its defenses for when it sees the whole virus so it is ready to conquer the infection before it can take hold.”
Currently the most commonly distributed live virus vaccines in use (aka a vaccine that includes part of the virus) include the chickenpox vaccine, and the measles, mumps and rubella (MMR) vaccine.
The term “live virus” shouldn’t put you on edge: While children can contract chickenpox after receiving the chickenpox vaccine, the organization immunize.org reported that a minute percent of those vaccinated develop a weak form of the disease.
5. Vaccines do not cause children to develop autism spectrum disorder.
One prevailing, harmful myth is that vaccines ― namely the MMR and chickenpox vaccines ― cause autism. Succinctly put by Dumford, there are a wealth of studies that have been conducted for over two decades that show no link between vaccines and autism spectrum disorder.
According to Sams, a reason this myth skyrocketed is because of widespread misinformation and unfortunate timing.
“Language development doesn’t occur until after one year of age, and the MMR and chickenpox vaccines are given at one year of age,” she explained, adding that some autistic children would struggle in reaching “standard” developmental milestones for that age, and that people inaccurately associate this with the vaccines.
6. Keeping up with your vaccinations and boosters goes beyond the individual health benefits. It can save loved ones and community members with preexisting conditions.
Vaccines are a crucial health strategy to achieve herd or population immunity― a term used to describe when the majority of people become immune to a disease. This provides a layer of protection to community members who cannot get vaccinated, or to those at higher risk.
“I like to point out that when you get vaccinated, you’re not just taking care of your health but [also] that of those around you,” Dumford said. “Using COVID or the flu as an example, if you are young and healthy, your case will probably be mild. However, if you pass it to an elderly loved one, or a loved one with a weakened immune system or with preexisting heart or lung problems, they may get a very severe case.”
Though misinformation surrounding vaccines can make it difficult to separate fact from fiction, Lee sees the political interest in vaccines as a potential way to “better engage the public in public health decisions.”
If you still feel uneasy about getting vaccinated, experts agree that you should seek out the advice of a board-certified doctor who can guide you in making informed health care decisions and answer any questions you may have.
“If you do not think you need the vaccine for yourself, get it for your new baby niece, your grandmother, or your uncle whose immune system is weak due to cancer treatment,” Lee concluded. “You never know whose life you can save by not passing on a contagious disease.”
