In researching vaccine requirements it seems that CDC recommends Yellow fever vaccine but coming from US Tanzania does not require it. I am unclear about Kenya because they say the Masai Mara game reserve has increased risk. Then there is statement that if you are over 60 there is increased risk of severe rxn to the vaccine. I am curious what those who are over 60 have done regarding vaccination especially Yellow fever. Is it required in Kenya, if you did not get it do you need an exemption letter?