plural vaccines
1
: a preparation that is administered (as by injection) to stimulate the body's immune response against a specific infectious agent or disease: such as
a
: an antigenic preparation of a typically inactivated or attenuated (see attenuated sense 2) pathogenic agent (such as a bacterium or virus) or one of its components or products (such as a protein or toxin)
a trivalent influenza vaccine
oral polio vaccine
Many vaccines are made from the virus itself, either weakened or killed, which will induce antibodies to bind and kill a live virus. Measles vaccines are just that, weakened (or attenuated) measles viruses.—
Ann Finkbeiner et al.
Ann Finkbeiner et al.… a tetanus toxoid-containing vaccine might be recommended for wound management in a pregnant woman if [greater than or equal to] 5 years have elapsed … .—Mark Sawyer et al.
Mark Sawyer et al.In addition the subunit used in a vaccine must be carefully chosen, because not all components of a pathogen represent beneficial immunological targets.—Thomas J. Matthews and Dani P. Bolognesi
Thomas J. Matthews and Dani P. Bolognesi
b
: a preparation of genetic material (such as a strand of synthesized messenger RNA) that is used by the cells of the body to produce an antigenic substance (such as a fragment of virus spike protein)
… Moderna's coronavirus vaccine … works by injecting a small piece of mRNA from the coronavirus that codes for the virus' spike protein. … mRNA vaccine spurs the body to produce the spike protein internally. That, in turn, triggers an immune response.—Susie Neilson et al.
Susie Neilson et al.The revolutionary messenger RNA vaccines that are now available have been over a decade in development. … Messenger RNA enters the cell cytoplasm and produces protein from the spike of the Covid-19 virus.—Thomas F. Cozza
Thomas F. CozzaViral vector vaccines, another recent type of vaccine, are similar to DNA and RNA vaccines, but the virus's genetic information is housed in an attenuated virus (unrelated to the disease-causing virus) that helps to promote host cell fusion and entry.—Priya Kaur
Priya KaurNote: Vaccines may contain adjuvants (such as aluminum hydroxide) designed to enhance the strength and duration of the body's immune response.
2
: a preparation or immunotherapy that is used to stimulate the body's immune response against noninfectious substances, agents, or diseases
The U.S. Army is also testing a ricin vaccine and has reported success in mice.—Sue Goetinck Ambrose
Sue Goetinck Ambrose… many of the most promising new cancer vaccines use dendritic cells to train the immune system to recognize tumor cells.—Patrick Barry
Patrick Barry
vaccine
adjective
Examples of vaccine in a Sentence
Recent Examples on the Web
Pregnant people should receive a Tdap vaccine between 27 and 36 weeks of pregnancy.
—Maia Pandey, Journal Sentinel, 21 Nov. 2024
Which is to say that America’s most prominent vaccine skeptic could have the power to upend, derail, or otherwise louse up a cornerstone of public health.
—Daniel Engber, The Atlantic, 20 Nov. 2024
His influence could affect future COVID vaccine recommendations.
—Maya Goldman, Axios, 20 Nov. 2024
Trump’s nomination of Robert F. Kennedy, Jr. to head Health and Human Services is likely to raise some fairly intense concerns among people with disabilities and chronic illness, who rely on vaccines and medications that Kennedy seems determined to limit or radically change.
—Andrew Pulrang, Forbes, 20 Nov. 2024
See all Example Sentences for vaccine 
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Maia Pandey, Journal Sentinel, 21 Nov. 2024
Which is to say that America’s most prominent vaccine skeptic could have the power to upend, derail, or otherwise louse up a cornerstone of public health.
—Daniel Engber, The Atlantic, 20 Nov. 2024
His influence could affect future COVID vaccine recommendations.
—Maya Goldman, Axios, 20 Nov. 2024
Trump’s nomination of Robert F. Kennedy, Jr. to head Health and Human Services is likely to raise some fairly intense concerns among people with disabilities and chronic illness, who rely on vaccines and medications that Kennedy seems determined to limit or radically change.
—Andrew Pulrang, Forbes, 20 Nov. 2024
See all Example Sentences for vaccine
Dictionary Entries Near vaccine
Cite this Entry
“Vaccine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/vaccine. Accessed 28 Nov. 2024.
Copy CitationKids Definition
vaccine
noun
vac·cine
vak-ˈsēn 
ˈvak-ˌsēn
: a preparation of killed, weakened, or fully infectious microbes that is given (as by injection) to produce or increase immunity to a particular disease
Etymology
from Latin vaccinus (adjective) "of or from cows," from vacca "cow" — related to buckaroo, vaquero
Word Origin
Toward the end of the 18th century, Edward Jenner, an English physician, made an important discovery. He observed that dairymaids who had the disease cowpox did not get smallpox, a much more serious disease. Working from this observation, he injected a person with material taken from another person's cowpox sores. He found out that this injection protected that person against the dreaded smallpox. He reported these findings in an article in which he used the Latin translation of cowpox, variolae vaccinae. The Latin word vaccinae was formed from the adjective vaccinus meaning "of or relating to cows." This word, in turn, was based on the noun vacca, meaning "cow." The cowpox material used for injections was then called vaccine. The injection itself was called vaccination. From this noun we created the verb vaccinate and the noun vaccinator.
Medical Definition
vaccine
noun
vac·cine
vak-ˈsēn, ˈvak-ˌ
1
: a preparation that is administered (as by injection) to stimulate the body's immune response against a specific infectious agent or disease: such as
a
: an antigenic preparation of a typically inactivated or attenuated pathogenic agent (such as a bacterium or virus) or one of its components or products (such as a protein or toxin)
a trivalent influenza vaccine
Extensive use of inactivated poliovirus vaccine (IPV) (starting in 1955) and live attenuated oral poliovirus vaccine (OPV) (beginning in 1961) led to a dramatic decrease in poliomyelitis incidence in the United States …—Mark A. Miller et al., The Journal of the American Medical Association
Mark A. Miller et al., The Journal of the American Medical Association… a tetanus toxoid-containing vaccine might be recommended for wound management in a pregnant woman if [greater than or equal to] 5 years have elapsed since the previous Td booster.—Mark Sawyer et al., Morbidity and Mortality Weekly Report
Mark Sawyer et al., Morbidity and Mortality Weekly ReportMany vaccines are made from the virus itself, either weakened or killed, which will induce antibodies to bind and kill a live virus. Measles vaccines are just that, weakened (or attenuated) measles viruses.—Ann Finkbeiner, et al., John Hopkins Magazine
Ann Finkbeiner, et al., John Hopkins Magazine
b
: a preparation of genetic material (such as a strand of synthesized messenger RNA) that is used by the cells of the body to produce an antigenic substance (such as a fragment of virus spike protein)
a COVID-19 vaccine
The Pfizer and Moderna vaccines are messenger RNA vaccines. They contain the genetic code for making the spike protein that the SARS-CoV-2 virus uses to latch onto and invade cells. Once injected, a person's cells read the code and then produce the protein.—Sharon Kirkey, The Star Phoenix (Saskatchewan, Canada)
Sharon Kirkey, The Star Phoenix (Saskatchewan, Canada)For an mRNA vaccine, the genetic message encoding for the protein antigen needs to be effectively delivered into the cells.—Angus Liu, FiercePharma
Angus Liu, FiercePharmaViral vector vaccines, another recent type of vaccine, are similar to DNA and RNA vaccines, but the virus's genetic information is housed in an attenuated virus (unrelated to the disease-causing virus) that helps to promote host cell fusion and entry.—Priya Kaur, Addison County (Vermont) Independent
Priya Kaur, Addison County (Vermont) IndependentNote: Vaccines may contain adjuvants (such as aluminum hydroxide) designed to enhance the strength and duration of the body's immune response.
2
: a preparation or immunotherapy that is used to stimulate the body's immune response against noninfectious substances, agents, or diseases
The investigational ricin vaccine, RiVax …, was effective in creating ricin-neutralizing antibodies in one of five participants given a low dose of the vaccine, four of five given an intermediate dose, and five of five receiving a high dose.—Amy Pfeiffer, Clinical Neurology News
Amy Pfeiffer, Clinical Neurology NewsDendritic cells play a key role in activating an immune response—whether against a foreign microbe or a damaged body cell—so many of the most promising new cancer vaccines use dendritic cells to train the immune system to recognize tumor cells.—Patrick Barry, Science News
Patrick Barry, Science News… these antigen-based cancer vaccines require gene transfer. They work best when administered to cells that are readily accessed by the immune system.—R. Michael Blaese, Scientific American
R. Michael Blaese, Scientific AmericanLove words? Need even more definitions?
Merriam-Webster unabridged
Share