vaccinations

I got checked. More importantly, if you travel from Zambia to anywhere else, you will get checked. Unless you want a week in quantine, get the shot.

I presume you are referring to the Yellow Fever inoculation/certificate; this takes at least 10 days before it becomes effective
(A) Depends on where you are travelling from, if from/returning to Europe/USA/SA then no yellow fever required.
If arriving from a WHO listed country then a YF cert is required, or otherwise an on-the-spot jab will be administered at a cost usually around $50/$60 with what may be a suspect needle, not to be recommended!
(B) However, if travelling on to another African (or some other) countries, then YF MAY be required. Although Zambia was removed from the YF infected country list by the WHO in 2003, some countries still consider Zambia to be a risk, and require a YF cert.
So although its a pain in the butt (actually in the arm!) it's best to get the jab, at least it lasts for 10 years, and you have it ready for your next jaunt into Africa (or South America)
Note that it is not recommended for over 60s, and is a no-no for people with egg allergy, in this case you will need a note from an inoculation centre, stating the reason for non compliance, in this case you will be required to report your intended location for 6 days after arrival, and to report any illness within that period.
Ivan