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Dear Ernst
I found some info for you. Please see the attached file. I have not
been able to check whether the vaccine is available in South Africa. If
I can be of any more assistance do not hesitate to contact me.
Ashwanth Singh
Principal Pharmacist
King Edward VIII Hospital
Durban
e-mail:ashsingh@iafrica.com
Tel:031-3603509/10/11
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OROCHOL (Berna, Switz.)
ACTIVE INGREDIENT(S):
An oral cholera vaccine.
INDICATIONS:
Active immunisation.
MANUFACTURER:
Schweiz. Serum- & Impfinstitut
Postfach
3001 Bern
Switzerland
ORAL CHOLERA VACCINES
Since parenteral cholera vaccines are not considered to be very effective,
providing at best 50% protection and confer immunity lasting only 3 to 6
months, attention has been turned towards oral vaccines which stimulate
intestinal immunity. Both killed and living oral vaccines have been
investigated, (1) and examples of both types are now available in some
countries.
Two oral killed vaccines have been evaluated in a double-blind
placebo-controlled study in an area of Bangladesh where cholera is endemic;
(2) results were obtained from a total of 62 285 children aged 2 to 15
years and women over 15 years. The vaccines consisted of either 1 mg of the
B subunit component of cholera toxin together with 1 x 10 (11) killed
whole-cell V. cholerae per dose (vaccine 1) or of just the killed whole
cells (vaccine 2); three doses of each vaccine were given at 6-week
intervals. Protective efficacy for the 3 years of follow-up was 62, 57, and
17% for vaccine 1 and 53, 57, and 43% for vaccine 2. Both vaccines
conferred approximately 50% protection over the entire 3 years. The decline
of protective efficacy during the third year resulted largely from complete
absence of protection of children vaccinated at or below the age of 5
years. Both vaccines conferred a higher level of protection against
classical cholera than against El Tor cholera. The evidence suggested that
2 doses of vaccine may be as effective as 3 doses.
Subsequent analysis (3) suggests that the vaccines not only prevent
symptomatic cholera but also protect against infection by V. cholerae O1.
Protection against asymptomatic infection was less than that against
symptomatic infection and occurred only in persons vaccinated after the age
of 5 years.
Additional studies have confirmed that two doses of killed whole cell-B
subunit vaccines, taken at least 7 days apart, and administered with a
suitable pH buffer, (4,5) produce adequate antibody responses and that
these vaccines protect against El Tor cholera which predominates in Latin
America. (6)
Three main approaches have been taken to develop live oral vaccines against
cholera: expression of V. cholerae antigens in attenuated Salmonella typhi,
attenuation of V. cholerae by deletion mutations that reduce virulence, and
attenuation of V. cholerae by mutations that affect nutritional
requirements. (1) A vaccine of the first type has produced significant
antibody responses to both V. cholerae and S. typhi antigens in healthy
subjects. (7) Two vaccines of V. cholerae strains resulting from the second
approach have been well tolerated and produced a significant immune
response. (8-12)
To date none of the available oral vaccines have been effective against V2E
cholerae O139, the strain responsible for the recent epidemic in Asia but
vaccines against this strain are being developed. (13)
1. Levine MM. Modern vaccines: enteric infections. Lancet 1990; 335:
958-61.
2. Clemens JD, et al. Field trial of oral cholera vaccines in Bangladesh:
results from three-year follow-up. Lancet 1990; 335: 270-3.
3. Clemens JD, et al. Evidence that inactivated oral cholera vaccines both
prevent and mitigate Vibrio cholerae O1 infections in a cholera-endemic
area. J Infect Dis 1992; 166: 1029-34.
4. Jertborn M, et al. Evaluation of different immunization schedules for
oral cholera B subunit-whole cell vaccine in Swedish volunteers. Vaccine
1993; 11: 1007-12.
5. Sanchez JL, et al. Safety and immunogenicity of the oral, whole
cell/recombinant B submit cholera vaccine in North American volunteers. J
Infect Dis 1993; 167: 1446-9.
6. Sanchez JL, et al. Protective efficacy of oral
whole-cell/recombinant-B-subunit cholera vaccine in Peruvian military
recruits. Lancet 1994; 344: 1273-6.
7. Forrest BD, et al. Immunogenicity of a candidate live oral
typhoid/cholera hybrid vaccine in humans. J Infect Dis 1989; 159: 145-6.
8. Levine MM, et al. Safety, immunogenicity, and efficacy of recombinant
live oral cholera vaccines, CVD 103 and CVD 103-HgR. Lancet 1988; ii:
467-70.
9. Suharyono, et al. Safety and immunogenicity of single-dose live oral
cholera vaccine CVD 103-HgR in 5-9-year-old Indonesian children. Lancet
1992; 340: 689-94.
10. Su-Arehawaratana P, et al. Safety and immunogenicity of different
immunization regimens of CVD 103-HgR live oral cholera vaccine in soldiers
and civilians in Thailand. J Infect Dis 1992; 165: 1042-8.
11. Barrett P, et al. Oral cholera vaccine well tolerated. Br Med J
1993;307: 1425.
12. Tacket CO, et al. Onset and duration of protective immunity in
challenged volunteers after vaccination with live oral cholera vaccine CVD
103-HgR. J Infect Dis 1992; 166: 837-41.
13. Coster TS, et al. Safety, immunogenicity, and efficacy of live
attenuated Vibrio cholerae O139 vaccine prototype. Lancet 1995; 345:
949-52.
PROPRIETARY NAMES
Cholera Vaccine BP 1993, Cholera Vaccine USP 23, Imovax Colera, Orochol,
Vac Anticolerica (FM)
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