Traveller,s vaccine : Yellow fever vaccine

If you have ever travelled abroad in some countries which are endemic or hyperendemic, you might have taken a vaccine for yellow fever. Though the disease does not exist in India but the Indian climate is optimum for a yellow fever virus to grow, the vector for this Aedes aegypti mosquito is also in abundance in India, but what is absent is the virus itself. Thus once the virus gets entry in the country it can spread the disease like a fire. So extreme caution is taken to stop the virus and all person are vaccinated when they travel abroad especially in countries of African sub continents.

Currently available yellow virus vaccine

Yellow fever vaccine is a live attenuated virus preparation made from 17D yellow fever virus strain. This vaccine virus family is the foundation for the 2 currently available vaccine type, 17D - 204 lineage and 17D D lineage. The former is used both in USA and Australia and the later is used in Brazil.

Use of yellow fever vaccine

It may be a question that when the disease yellow fever does not exist in India then what is the use of yellow fever vaccine. The answer is that the person travelling abroad if not vaccinated may carry the virus and the disease may occur. Thus children aged 9 month or more and all adults travelling to or living in areas of South Africa, Africa where the yellow fever vaccination is officially reported should be vaccinated.

Vaccination is also recommended for travellers to countries that do not officially report the disease but that lie in the yellow fever endemic zone.

Why infants below 9 months of age should not be vaccinated for yellow fever

Calculation of age specific rate of yellow fever vaccine associated encephalitis is impossible as age specific vaccination records are not available. Several reports show higher incidence of encephalitis below 9 months of age and the vaccine contains live virus so the FDA and the manufacturer recommends that vaccination for yellow fever of infants below 9 months should be avoided.

Last but not the least for Indian population it is recommended as stated earlier that all permanent Indian resident should take yellow fever vaccine while travelling to countries where yellow fever is endemic or hyperendemic.