Terri, you may not need it anyway, see below taken from NHS website.
The yellow fever vaccine provides lifelong protection for most people.
A further dose of vaccine is recommended for a small number of travellers who are visiting yellow fever risk areas, including those who were previously vaccinated when they were:
pregnant
under 2 years old
living with HIV
had a weakened immune system
before having a bone marrow transplant
Rarely, a further dose of vaccine may also be advised if there's a concern about the traveller's risk of yellow fever, for example, if they're working or living for some time in a high-risk area.