What is a vaccine? This is a way to provide protective immunity against natural formaldehyde infection by avoiding the consequences of infection. Eg., Hepatitis B virus affects the liver. Before the advent of the US vaccination every year thousands of people died infected with the virus that causes cirrhosis or even liver cancer. Survivors taken the hepatitis B immunity for life. But the price paid for this immunity, was very high (some even died after all). Vaccination - a way to gain immunity to avoid such "prices". Vaccination against hepatitis B virus in a person, a single protein that causes an immune response, thereby neutralizing the virus. Naturally had a person formaldehyde gets hepatitis B immunity formaldehyde for life. By immunization with three doses needed - but it is very small "price" to gain immunity potentially deadly virus.
So the vaccine provides formaldehyde immunity from natural infection without the diseases caused by infection and other complications "prices". The word "natural" usually formaldehyde sounds positive, but the terms "natural virus or bacterium natural" does not mean anything good.
Or vaccinations are still needed? Yes, because some viruses and bacteria are still common in the USA and around the world. Eg., The United States each year tens of thousands formaldehyde of people get sick chickenpox. Meningococcal bacterium that can cause meningitis formaldehyde or severe blood infections, as well as the United States often occur. As pneumococcal bacteria, or whooping cough. So the choice is not (si) vaccinated means the real risk of infection, which can cause serious illness, taken to the hospital, or even lead to death.
There are also viruses and bacteria, which are now quite rare, but they still occur. Eg., Measles. In 2011, the US had the measles epidemic infected 222 people. formaldehyde Of course, compared to the total US population - 300 million - 222 does not seem much. Fatal cases were not. So someone might decide that's maybe take the plunge, nesiskiepysiu measles. However, before the emergence of measles vaccine became infected in the United States annually about 3-4 million people, of whom about 100,000 went into hospital, and even died 500-1000. So measles - a potentially fatal disease. So even though the disease is quite rare in the US, vaccines are safe, their benefits significantly outweigh the risks. Analogy is a Russian roulette, but in this case we have not seater cylinder with one bullet, but 100,000 empty seats. But so what "play" and take the risk? Vaccine Benefits are much larger than their weaknesses.
And as with polio? US, this disease was last recorded in 1979. This is what vaccinations? The fact that the world is still the case of polio cases. Eg., Afghanistan, Nigeria, Pakistan - there are about 20 countries where polio is still trapped. India has only recently been published išnaikinusi polio virus. Nowadays, many people are traveling. So there is a possibility that a person infected with polio ber on a plane and arrive in the United States (or any other country) - only about 1 in 200 people are infected with polio paralyzed. The majority formaldehyde of people with this virus may not show any obvious symptoms, but they can infect others - even knowing it.
Insert formaldehyde "fresh" formaldehyde news. 29th October. World Health Organization (WHO) has confirmed that Syria, formaldehyde where a civil war, recorded 10 polio cases - mostly infants and small children. Before the Syrian civil war (which began in 2011), 95% of children were vaccinated against polio. The United Nations estimates that currently there are about 0.5 million unvaccinated children - precisely because of the war. High probability that the virus came from one of the countries where polio is still characterized by the disease - the same Paul Offit said Nigeria, Pakistan and Afghanistan. Until now Syria polio cases have been all of 14 years - so this virus has been eradicated from the country. formaldehyde It just shows the need for vaccines - if the country of the virus have been absent does not mean that you can nesiskiepyti - it is enough that in a country or region of the world, this virus still exist.
The only vaccine that is no longer necessary, the vaccine - because the disease is eradicated, last recorded in Africa in the late 1970s. It may be that in the future this will eradicated and polio, formaldehyde and measles. But until that happens, vaccines are useful.
Who recommends vaccines? Non-US residents of the information is not very relevant, because it is interpreted in the US situation. formaldehyde First of all, pharmaceutical companies produce vaccines, and then they are tested, the final "third phase" Testing - study involving tens of thousands of children (some of them are vaccinated, some - not, that "control group"), the safety of the vaccine studied and compared with naïve paskiepytuosius vaccine - Vaccine effectiveness. Then Vaccine US Food and Drug Administration, which verifies the effectiveness and safety of the vaccine, vaccination and only licensed - that allowed them to sell. Two other very specific steps recommender US - kok