English to Russian Medical Medical (general) A Parent\'s Guide to Vaccination (Canadian Pediatric Society)

Two ways to immunity
There are two ways to achieve immunity: by ****natural infection**** and by vaccine. Now that you know how the immune system works, you may wonder whether there is a difference in the immunity achieved by vaccine as opposed to infection. To illustrate how natural infections and vaccines produce a very similar end result—long-term immunity—let’s use measles as an example.

***Natural infection***. The first time someone is exposed to the natural form of the measles virus, the virus infects many cells and causes illness in the person before the immune response can develop. Infection from measles can do a lot of damage. In severe cases, the infection spreads so rapidly that the person dies before immunity can be established. Once a person has had measles and survived, long-term immunity is established. Immunity after measles infection lasts a very long time, usually for life.
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Following vaccination, the immune system responds as if ***natural infection*** has already occurred.

(?) перенесение инфекционного заболевания

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