Facts about human viruses

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Cancer often takes years, even decades, to develop after a person gets HPV. Genital warts and cancers result from different types of HPV. There is no way to know who will develop cancer or other health problems from HPV.

They may also be more likely to develop health problems from HPV. Get vaccinated. The HPV vaccine is safe and effective. It can protect against diseases including cancers caused by HPV when given in the recommended age groups. Get screened for cervical cancer. Routine screening for women aged 21 to 65 years old can prevent cervical cancer. Vaccination is not recommended for everyone older than age 26 years. However, some adults age 27 through 45 years who are not already vaccinated may decide to get the HPV vaccine after speaking with their healthcare provider about their risk for new HPV infections and the possible benefits of vaccination.

HPV vaccination in this age range provides less benefit. Most sexually active adults have already been exposed to HPV, although not necessarily all of the HPV types targeted by vaccination.

At any age, having a new sex partner is a risk factor for getting a new HPV infection. People who are already in a long-term, mutually monogamous relationship are not likely to get a new HPV infection. There are HPV tests that can screen for cervical cancer. Healthcare providers only use these tests for screening women aged 30 years and older. HPV tests are not recommended to screen men, adolescents, or women under the age of 30 years.

Most people with HPV do not know they have the infection. They never develop symptoms or health problems from it. Some people find out they have HPV when they get genital warts. Although viruses can have devastating health consequences, they also have important technological applications. Viruses are particularly vital to gene therapy. Because some viruses incorporate their DNA into host DNA, they can be genetically modified to carry genes that would benefit the host.

Some viruses can even be engineered to reproduce in cancer cells and trigger the immune system to kill those harmful cells. Although this is still an emerging field of research, it gives viruses the potential to one day do more good than harm.

Antibiotics do not stop viruses. Also called the flu. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited. Tyson Brown, National Geographic Society. National Geographic Society. For information on user permissions, please read our Terms of Service.

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You cannot download interactives. People get sick when another organism, big or small, invades their body and infects them. These infectious agents come in all shapes and sizes, and all of them pose different threats to the human body. Some are microscopic, such as bacteria or viruses, which attack human bodies on the cellular level.

Others are larger, like fungi, which are unicellular or multicellular organisms that grow on and feed off organic material, including humans.