How effective is the cholera vaccine, and who should get it?
The cholera vaccine protects only about 50 percent of the persons who are injected with it, and it is completely ineffective against some strains of the bacteria. Two doses are recommended for people at highest risk and should be given one week to one month or more apart. Boosters are necessary every six months if the risk of disease persists. Protection starts about two weeks after the second dose. Luckily, the risk of cholera is so low that the vaccine is not recommended for U.S. travelers. And no country currently requires cholera vaccine for entry. Despite World Health Organization recommendations, however, local authorities in some areas (such as in Africa) demand proof of cholera vaccination or a medical exemption certificate for entry. If you have neither of these, you may be faced with having your itinerary rearranged abruptly or with border patrol offering on-the-spot single dose cholera vaccination (which greatly increases your risk of HIV and hepatitis B). Some travel expert
