<unk> s are vaccines which prevent<unk> . When given to a majority of the population they decrease complications at the population level. Effectiveness when 90% of a population is vaccinated is estimated at 85%. Two doses are required for long term prevention. The initial dose is recommended between the age of 12 and 18 months of age. The second dose is then typically given between two years and six years of age. Usage after exposure in those not already immune may be useful. Side effects are generally mild. It may cause mild pain and swelling at the site of injection and mild fever. More significant side effects are rare. Evidence is insufficient to link the vaccine to complications such as neurological effects. The vaccine should not be given to people who are pregnant or have very poor immune system function. Poor outcomes among children of mothers who received the vaccine during pregnancy, however, have not been documented. Even though the vaccine is developed in chicken cells, it is generally safe to give to those with egg allergies. Most of the developed world and many countries in the developing world include it in their immunization programs often in combination with measles and rubella vaccine known as MMR. A formulation with the previous three and the varicella (chickenpox) vaccine known as MMRV is also available. As of 2005, 110 countries provided the vaccine as part of their immunization programs. In areas where widespread vaccination is carried out it has resulted in a more than 90% decline in rates of disease. Almost half a billion doses of one variety of the vaccine has been given.
Mumps vaccine
Polio vaccine
Typhus vaccine
Smallpox vaccine
Typhoid vaccine
Measles vaccine
Rabies vaccine
Varicella vaccine