The NHS only suggests vaccinations for travel destinations for a very good reason: we really do need them. You need to bear in mind that most other countries in the world are not as safe as the United Kingdom. The climate will often have a lot to do with this and also the fact that the health system is often quite dilapidated in comparison to our own.
In some of the poorest countries of the world, especially in Africa, first aid kits may be helpful but it is the other diseases and illnesses out there that pose the greatest threat to your safety and even your life.
By far, the biggest of all of these threats today is the dreaded malaria. If you are travelling to countries such as Tanzania, Zambia, Kenya etc., it is essential you take a course of anti-malarial medicine. These are very expensive and not included on the NHS. Also, they can only be prescribed through your local health centre.
If you find out that you need anti-malarial medication for the country you are visiting, you will need to start taking this course before you travel, whilst you are there, and even for a number of weeks upon your return. It is absolutely imperative that you complete this entire course, otherwise you significantly increase the risk of contracting this potentially fatal condition.
There are many other vaccines that may be required also. Typhoid, yellow fever and tetanus are just a few examples and you will need to chat with your local health centre, before you travel, to find out more about this.