In pictures: Ethiopia's remote people

The chief says the injections saved the people from extinction.

But now there is a new threat – the Bumi people from nearby Uganda who raid Surmaland.

They have many more guns than the Surma, who have lost about a third of their territory in the last 20 years.

The need to defend their land has led some Surma to swap their traditional wooden "donga" fighting sticks for "klach" (Kalashnikovs).