World Health Organisation, WHO, has concluded that a single dose of vaccination is sufficient to confer life-long immunity against the yellow fever disease.
It said since yellow fever vaccination began in the 1930s, only 12 known cases of post-vaccination have been identified, after 600 million doses have been dispensed.
The article said evidence shows that among this small number of vaccine failures, all cases developed the disease within five years of vaccination, which demonstrates that immunity does not decrease with time.
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