The initiative, Get On Africa, will see celebrities join a group of health workers from Riders for Health in the mountainous Kingdom of Lesotho, where they will deliver vital medical supplies by motorbike to clinics, after learning to ride off-road.
Capitalize head of PR Jonathon Bates said: 'People often underestimate the skills required to learn to ride a motorbike and do not always focus on the positive aspects of riding.
'These are the messages we are hoping to convey to the nation with Get On Africa.'
The celebrity line-up includes TV presenter Gethin Jones, screen actress Jill Halfpenny, former England cricket legend Darren Gough and Coronation Street stars Shobna Gulati and Oliver Mellor.
Lesotho has one of the severest HIV problems in the world, with nearly one in four adults infected and almost one in three children born with the virus.
Riders for Health provides motorbikes to local health workers so they can deliver healthcare to remote communities across Africa.
Capitalize will handle all PR and event management for the expedition on behalf of Get On, the UK motorcycle industry's campaign to promote the benefits of life on two wheels. The agency's remit includes a national campaign using social and digital media, as well as traditional outlets.