As a Peace Corps volunteer, I remember getting 2 injections before leaving the States, and 11 over the course of my first year in Namibia. You’ll be happy to know that you don’t have to go vaccination crazy like I did. If you’re routine vaccinations are up-to-date, you might not need anything. The wedding will be in a rural area, but you’re only going to be there for a short time, so the risk is quite minimal. For those who want to be 110% sure, you can look at getting vaccines for Yellow Fever, Typhoid, Rabies, Hepatitis A & B, and Polio.
If you’re considering getting vaccines, this is something you should get started on sooner than later. For example, both Hepatitis A & B require multiple injections over a period of about 6 months, so if you want to be fully covered and up-to-date, you should get started soon.
When I got malaria in Ghana, it felt pretty bad. But, the good news is that malaria should not be a concern for you in August in Northern Namibia. I will say it again: if I were you, I would not take malaria medications for this trip. Omuthiya is an area where malaria is found in the rainy season, but August is about 5 months after the last rains, and by that time, mosquitoes are gone, and malaria is too.
That being said, if you are still considering taking a malaria prophylaxis you should know that all malaria-prevention medications have drawbacks. Some cost around US$7 per day. Others have unpleasant side effects, like sun sensitivity (not so good for Africa…), hyper-realistic and often violent dreams, or antibiotics used as a malaria prevention that, over time, suppress your immune system. These turn-offs were big enough for me to stop taking my malaria prophylaxis immediately after the rainy season while I was living in a malaria area, and I haven’t taken them since. (I also haven’t gotten malaria since.)
For additional information on vaccinations and malaria prevention, the internet is your friend. Two great sources for travel health information are the CDC and the World Health Organization. Another idea is to check for a travel clinic in your area. There, you can talk to a doctor who specializes in travel medicine, and get yourself immunized against anything they recommend.