With flu season in full swing and illnesses surging around the holidays, now is the perfect time to discuss one of America’s most polarizing science topics: vaccines. Misconceptions about vaccines are widespread, this article seeks to debunk some of these myths and explain how different types of vaccines work.
Vaccines were first notably used in the late 18th century and have since become powerful tools for creating herd immunity—a term that describes when a majority of the population is indirectly protected from disease through vaccination or previous infection. Below is an overview of the different types of vaccines and how they function.
Inactivated Vaccines:
Inactivated vaccines are commonly used to protect against influenza (the flu), hepatitis A, polio, and rabies. These vaccines use a "killed" version of the disease-causing germ. While effective, their inactivation can limit the immune response, often needing follow-up vaccinations to maintain long-term immunity.
Live-attenuated Vaccines:
Live-attenuated vaccines defend against diseases like measles, mumps, and rubella (MMR), rotavirus, chickenpox, smallpox, and yellow fever. These vaccines are often administered early in life, as they are required for entry into primary schools. "Attenuation" simply means the germ is in a weakened state before being introduced into the body.
mRNA Vaccines (Messenger RNA):
There are many misconceptions about the mRNA vaccine technology used for COVID-19 vaccines in 2020. First, this technology has been studied for decades and wasn’t developed solely for coronavirus. Second, mRNA vaccines do not alter DNA. Instead, they introduce a template (messenger RNA) that allows our bodies to produce proteins, prompting an immune response. One major advantage of mRNA vaccines is that they don’t contain live viruses, so they cannot cause the disease they aim to prevent.
Subunit, Recombinant, Polysaccharide, and Conjugate Vaccines:
These vaccines are used to prevent diseases such as hepatitis B, HPV, whooping cough, Hib, pneumococcal disease, meningococcal disease, and shingles. They work by introducing parts of the germ—such as proteins or sugars—to the immune system. A key benefit is they are safe across all populations, including immunocompromised individuals. Like inactivated vaccines, "boosters" are often needed for long-term immunity.
Why Vaccines Matter
Research into vaccines is ongoing, with new discoveries and clinical trials constantly improving their effectiveness against current and emerging diseases. Understanding how vaccines work is crucial for combating misinformation and reducing anti-vaccination sentiment, which poses serious public health risks.
For instance, a major measles outbreak occurred in New York City in 2019, infecting over 100 children. Eight were hospitalized, and one required intensive care. This outbreak happened nearly two decades after measles was declared eliminated in the U.S. in 2000, highlighting the risk posed by declining vaccination rates combined with international travel. Read more about the New York outbreak here.
Overcoming Vaccine Hesitancy
With vaccines often politicized and misinformation spreading rapidly, it’s understandable to feel uncertain about their safety and efficacy. If you have concerns, reach out to your primary care physician or a trusted health professional. Vaccination not only protects you but also those around you.
To find a vaccination site near you, visit vaccines.gov. For a more detailed breakdown of how vaccines work, check out the CDC’s guide to vaccines.
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Assessed and Endorsed by the MedReport Medical Review Board