Changes

Only live attenuated vaccines can still cause infection.The other three types of vaccines can cause illness, but this is an allergic response not due to the disease itself. Very rarely a serious disease known as [[eczema vaccinatum]] can emerge. Vaccines that use pieces of pathogens often use a [[carrier virus]] in the injection. Those with very weak immune systems that are exposed to such a vaccine can become infected with the carrier virus and develop [[eczema]]. A recent case of this was reported in the United States after a military man was vaccinated with small pox and his two year old son became ill. <ref> http://www.associatedcontent.com/article/183349/soldier_infects_toddler_son_with_lifethreatening.html AP article on eczema vaccinatum </ref>

Only live attenuated vaccines can still cause infection.The other three types of vaccines can cause illness, but this is an allergic response not due to the disease itself. Very rarely a serious disease known as [[eczema vaccinatum]] can emerge. Vaccines that use pieces of pathogens often use a [[carrier virus]] in the injection. Those with very weak immune systems that are exposed to such a vaccine can become infected with the carrier virus and develop [[eczema]]. A recent case of this was reported in the United States after a military man was vaccinated with small pox and his two year old son became ill. <ref> http://www.associatedcontent.com/article/183349/soldier_infects_toddler_son_with_lifethreatening.html AP article on eczema vaccinatum </ref>

Since the adoption of vaccination, however, many diseases have been curbed. [[Polio]], for example, killed over 3,000 people in the United States in 1952 [http://www.cdc.gov/nchs/data/vsus/VSUS_1952_2.pdf], and inflicted such noted persons as President [[Franklin Delano Roosevelt]], actor [[Alan Alda]], and musician [[Itzak Perlman]]. When doctors began using a vaccine to fight polio, it practically eradicated the disease in the developed world.  

Since the adoption of vaccination, however, many diseases have been curbed. [[Smallpox]], a deadly disease responsible for the deaths of millions, has been mostly eliminated through vaccination. Responsible for an estimated 300 to 500 million deaths worldwide in the 20th century, effective vaccination programs of the 19th and 20th century were effective at curbing the disease, and in 1979 the World Health Organization declared smallpox to be eradicated.

Other diseases that have been curbed since the invention of vaccines include [[smallpox]] (previously a yearly killer of thousands worldwide), [[measles]], [[mumps]], [[rubella]], and [[typhoid]].

 

Other diseases that have been curbed since the invention of vaccines include [[measles]], [[mumps]], [[rubella]], and [[typhoid]].

== Influenza Vaccine and microevolution==

== Influenza Vaccine and microevolution==