This information has been reviewed and approved by Reeti Khare, PhD (June 2020).
The virus enters the body through the nose, mouth, eyes or the skin.
Once inside the body, a virus infects a host cell by injecting its genetic material.
The virus will hijack the cell in order to make many copies of itself and to hide from the immune system.
The host cell dies as the virus multiplies and moves into more cells. This is when the body gets sick.
The immune system can protect the body from low-level attacks and adapt to viral infections, so that they won't cause disease again or are less severe. Antiviral medications also can help protect against viral diseases.
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The information on our website is medically reviewed and accurate at the time of publication. Due to the changing nature of the COVID-19 pandemic, information may have since changed. CDC.gov and your state’s health department may offer additional guidance.