from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A preparation of a weakened or killed pathogen, such as a bacterium or virus, or of a portion of the pathogen's structure that upon administration to an individual stimulates antibody production or cellular immunity against the pathogen but is incapable of causing severe infection.
  • noun A preparation from the cowpox virus that protects against smallpox when administered to an individual.
  • noun Computers A software program designed to detect and stop the progress of computer viruses.

from The Century Dictionary.

  • Of or pertaining to cows; derived from cows: as, the vaccine disease, or cowpox.
  • Of or relating to vaccinia or vaccination.
  • noun The virus of cowpox or vaccinia, used in the process of vaccination as a preventive of smallpox.
  • noun In a general sense, the modified virus of any specific disease introduced into the body by inoculation, with a view to prevent or mitigate a threatened attack of that disease or to confer immunity against subsequent attacks.
  • noun Also vaccin.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective Of or pertaining to cows; pertaining to, derived from, or caused by, vaccinia.
  • adjective Of or pertaining to a vaccine or vaccination.
  • noun The virus of vaccinia used in vaccination.
  • noun any preparation used to render an organism immune to some disease, by inducing or increasing the natural immunity mechanisms. Prior to 1995, such preparations usually contained killed organisms of the type for which immunity was desired, and sometimes used live organisms having attenuated virulence. Since that date, preparations containing only specific antigenic portions of the pathogenic organism have also been used. Some of these are prepared by genetic engineering techniques.
  • noun (Computers) A program designed to protect a computer from software viruses, by detecting and or eliminating them.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun immunology A substance given to stimulate the body's production of antibodies and provide immunity against a disease, prepared from the agent that causes the disease, or a synthetic substitute.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun immunogen consisting of a suspension of weakened or dead pathogenic cells injected in order to stimulate the production of antibodies


from The American Heritage® Dictionary of the English Language, 4th Edition

[From Latin vaccīnus, of cows, from vacca, cow.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin vaccinus, from vacca ("cow") (because of early use of the cowpox virus against smallpox). Cf. New or Scientific Latin (variola) vaccīna, or "cowpox".


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  • * obama: h1n1 vaccine 'strongly recommended'* pregnant women express fears over swine flu vaccine* cdc warns neurologists to watch for nerve disease after shots* h1n1 unlikely to mutate into' superbug ': US study* swine flu won't be as dangerous as we thought, uk official says* pfizer agrees record fraud fine* envirohealth: intl paper treads monsanto's path to' frankenforests'* more geo-engineering: can man-made 'volcanoes' slow down climate change?

    media monarchy 2009

  • Many people incorrectly assume that a choice not to get a vaccine is a risk-free choice.

    Vaccines and Society 2010

  • The other vaccine is the human papillomavirus (HPV) vaccine.

    Hepatitis B Vaccine 2009

  • One of the factors in favor of the vaccine is the fact that girls can live a pure life and still get this disease later from a spouse/partner who made bad decisions at a younger age.

    Do We Really Need Gardasil To Protect Teen Girls? 2009

  • Finally, the cost of the vaccine is likely to be similar to that of getting the blood work, so if a vaccine is then necessary, the cost will also be higher when the same could have been accomplished by just administering the vaccine.

    Measles, Mumps, Rubella (MMR) 2010

  • The influenza vaccine is the only vaccine that needs to be given at a particular time of the year.

    Age groups and vaccines — Grandma, Grandpa and other adults 2010

  • But now the vaccine is almost here, the question is, “Do you want it?”

    What to know about getting H1N1 vaccine 2009

  • The choice not to get a vaccine is a choice to risk the disease that the vaccine prevents.

    Vaccines and Society 2010

  • Immunity from legal suits in this case means if the vaccine is a suspected cause of death or injury, the law will not allow victims to sue the vaccine manufacturer.

    Flu shots can give a different kind of immunity : Law is Cool 2009

  • Like the infant vaccine, this vaccine is administered with tetanus and diphtheria vaccines as a shot.

    Tetanus, Diptheria, Pertussis 2010


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  • See vaccimulgence for a surprise.

    September 30, 2007

  • "Nowhere was pneumonia more severe than among workers in South Africa's gold and diamond mines. Epidemic conditions were virtually constant and outbreaks routinely killed 40 percent of the men who got sick. In 1914 South African mine owners asked Sir Almroth Wright to devise a vaccine against pneumonia. He claimed success. In fact he not only failed, his vaccinations could kill. This and other errors earned Wright the mocking nickname 'Sir Almost Right' from competing investigators."

    —John M. Barry, The Great Influenza (NY: Penguin Books, 2004), 154

    (Note for posterity: Sir Almroth Wright had been knighted for developing a typhoid vaccine.)

    February 14, 2009