The main reason for dropping the recommendations could be tacit admission that there is no effective vaccine to date. The killed injected vaccine, which offered protection (if at all) for only a few months (Ind J Biochem & Biophys, 1994; 31: 441-8), is now being replaced by a number of whole cell and live vaccines. Some studies of the killed oral WC/rBS vaccine were promising, showing a protection of 85 per cent after six months, but largely among patients with type O blood (Lancet, 1994; 344: 1273-6). A 1993 Vietnamese trial of the killed oral cholera vaccine showed an effectiveness of only 60 per cent, leading doctors to experiment with a single dose of the live oral CVD vaccine. Nevertheless, experience demonstrated the vaccine only offers protection against certain strains (Lancet, 1997; 349: 957 and 1992; 340: 689-93). It's known, for instance, that the vaccine doesn't protect against a new strain, known as Bengal cholera, that has emerged in southern Asia.
In July 1994, in one of the worst cholera outbreaks in recent times, 12,000 Rwandan refugees died in Goma (eastern Zaire). This strain was also resistant to tetracycline and doxycycline, used to treat cholera (JAMA, 1996; 276 (5): 348). Other multiple drug resistant strains have emerged in Honduras (Lancet, 1997; 349: 924).
Besides fever, you can experience serious allergic reactions to this drug, nerve damage, and even mental problems (Infection & Immunity, June 1996; 64 (6): 2362-4). In one study, cholera vaccine may be responsible for transverse myelitis (J Royal Society of Med, 1990; 83; 653).
Other studies have shown pancreatitis (Br J Clin Pract, 1986; 40: 300-1); hepatitis B (Presse Medicale, 1986; 15: 1331); immune complex disease (Trans Royal Soc Trop Med & Hygiene, 1984; 78: 106-7); stroke (Lancet, 1985; 2: 1372); sudden death (Forensic Science Inter, 1984;
24: 95-8); myocarditis (Deutsche Med Wochenschrift, 1984; 109: 197-8); and psychiatric complications (Acta Neurological, 1974; 29: 520-33). Occasionally side effects are heightened when cholera has been given with typhoid vaccine (Beitrage zur Pathologie, 1976; 158: 212-24). The live (oral) form is purported to have fewer side effects (BMJ, 1993; 307: 1425).
Simply obeying certain hygiene rules, particularly concerning water and uncooked food, and replacing lost fluids may protect you against all forms of cholera; studies have shown that a healthy person can have more than a billion cholera bugs in their body without developing the disease (Times, June 3, 1993).
The most important element is to avoid the effects of severe diarrhea, which is what eventually kills you. A patient with cholera can lose virtually twice their weight in fluid in a single day (see Alternatives, p 6, for tips on rehydrating after diarrhea).
Some data has suggested that getting cholera and yellow fever vaccines simultaneously will decrease the response of both. Although this data is disputed, Wyeth-Ayerst, who produce the injected cholera vaccine, recommends that each be given in no less than a three week interval of the other.
Typhoid fever (caused by Salmonella typhi) is also spread by contaminated food and water. In Britain, some 200 people come home from holiday each year with typhoid. Typhoid vaccine is recommended for those travelling to areas where they may be exposed to contaminated food and/or water, particularly where the disease is common or sanitation particularly primitive. In practice, if you follow the lists put together by the Department of Health, you can end up getting shots even if you are heading off for a first class holiday in the Caribbean.