What are the moral obligations of the traveller in relation to vaccination?

More and more people each year are involved in international travel for reasons of business and pleasure. Such travel brings great economic and social benefits but it also has serious potential medical costs because it creates greater opportunities for the spread of infectious disease. In this paper, I discuss the ethical issues relating to a traveller's responsibility to be vaccinated against infectious diseases (where such vaccinations exist). What are the relevant moral obligations, in this situation? What are the boundaries of legitimate restrictions that can be placed upon an individual for the sake of protecting others from disease? Do we have extra special obligations to protect others from harm when we choose to travel abroad (beyond those we might have to other people in our own country)? I explore two different arguments suggesting that we do have an obligation to be vaccinated in this case. The first argument is built upon the potential harm to other people that might arise in the case of vaccination-refusal, and the second argument looks at the need to contribute to the preservation of public goods, such as herd protection.