Having booked a tour of South America with CTS Horizons, we visited our doctor to organise yellow-fever vaccinations. We were shocked to learn that the World Health Organisation says the side effects for those over 60 can be serious, including multi-organ failure. We decided to cancel and asked for our deposit to be returned – had the company informed us of this, we would never have booked the trip. CTS has refused. This is extremely unfair. Peter Stimpson, Woking

CTS Horizons replies: “We offer holidays to many parts of the world. As each person’s circumstances will differ, it would not be appropriate to give specific health advice. We would like to offer to transfer Mr Stimpson’s deposit to another trip, since we do not wish to penalise clients for making considered choices on risk factors.

To put the risk into context, in the case of yellow-fever vaccinations for the over 60s, there is a 1:40,000 risk of a problem. Compare this with a stated risk of 1:20,000 of dying in a plane crash.

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