International clinical trials of HIV vaccines: I. Phase I trial of an HIV-1 synthetic peptide vaccine in Bangkok, Thailand.

A randomized, double blind, placebo controlled Phase I trial of a prototype human immunodeficiency virus type 1 (HIV-1) synthetic peptide vaccine was conducted in Bangkok, Thailand, to evaluate the safety and immunogenicity of the vaccine in a population of healthy adults at low risk for HIV infection, and to establish essential infrastructure for future HIV vaccine trials in Thailand. Thirty volunteers (25 males; 5 females) were recruited and randomized into 3 groups, receiving 3 intramuscular injections of either 100 micrograms vaccine (N = 12) or 500 micrograms vaccine (N = 12) or alum placebo (N = 6) on weeks 0, 4 and 25. The vaccine was well tolerated without any serious adverse effects. HIV-1 specific ELISA responses were detected in 20/24 subjects who received the vaccine, with V3 binding antibody titers ranging from 1:69 to 1:5,041. HIV-1 (MN) specific neutralizing antibody was detected in 19/20 of subjects with detectable HIV-1 specific binding antibody. Neutralization titers ranged from 1:14 to 1:1,294, which were less than titers observed in HIV-infected subjects. The results of this study indicate that the vaccine was well tolerated, and that the vaccine stimulated anti-HIV humoral immune responses in Thai subjects. The successful undertaking of this first HIV vaccine trial conducted in Thailand provided important preparatory information surrounding volunteer recruitment and motivations, and paves the way for future trials of HIV vaccines in Thailand.

Sexual risk behaviour reduction associated with voluntary HIV counselling and testing in HIV infected patients in Thailand.

Sexual risk behaviour, measured by anonymously self-reported sexual activity, number of sexual partners, and condom use rates, was studied in age- and gender-matched HIV-1 positive consecutive patients from the Thai Red Cross Immune Clinic (IC) (study group, questioned after voluntary HIV counselling and testing) and the Thai Red Cross Anonymous Clinic (AC) (control group, questioned before voluntary HIV counselling and testing) in Bangkok, Thailand in 1993/94. More than 80% of study patients reported having decreased their sexual activity and their number of sexual partners since receipt of the positive HIV test result. Compared to control patients, study patients reported more often abstaining from sex (42% vs 14%), and more often using condoms during all their last three incidences of sexual intercourse (44% vs 14%). These findings give evidence for the value of voluntary HIV counselling and testing in contributing to the reduction of HIV transmission in Asia.

Knowledge, attitudes and behaviour among HIV-positive and HIV-negative clients of a confidential HIV counselling and testing centre in Thailand.

OBJECTIVE: To describe the clients, operation and impact of an Asian public HIV counselling and testing centre. DESIGN AND SETTING: Analysis of samples from clients attending the Thai Red Cross Anonymous Clinic (TRC-AC) in Bangkok, Thailand in 1993. SUBJECTS: HIV-positive and HIV-negative consecutive clients (250 of each). MAIN OUTCOME MEASURES: HIV seroprevalence rates, knowledge, attitudes and behaviour. RESULTS: Overall HIV-1 prevalence was 16%; 13% in men and 24% in women. Reasons for requesting an HIV test were high-risk behaviour (21%), feeling unwell (20%), checking a previous HIV test result (18%), a planned marriage or new relationship (10%), and planning a baby (5%). Heterosexual risk behaviour was reported by 85% of clients, while in each case only 1% reported male homosexual or intravenous drug use risk behaviour. Factors associated with HIV infection on univariate analysis included a history of sexually transmitted disease, not using condoms, a low level of education and salary, and being female. Knowledge about HIV transmission risks and AIDS prevention measures was good, and most clients expressed a caring attitude towards people with HIV and AIDS. A former negative HIV test result was associated with higher levels of condom use, and most clients expressed the intention to reduce their HIV risk behaviour in response to a positive or negative HIV test result (more so if positive). CONCLUSIONS: Our study demonstrates the demand for and the feasibility of confidential HIV counseling and testing services in Thailand and illustrates the value of these services in achieving behaviour changes. Such services should be considered as an additional approach for reducing HIV transmission in Asia, especially in areas with high HIV seroprevalence rates.

PIP: Data are presented from HIV serodiagnoses and knowledge, attitude, and behavior questionnaire responses for 250 HIV-positive and 250 HIV-negative consecutive clients attending the Thai Red Cross Anonymous Clinic in Bangkok, Thailand in 1993. The study was conducted to describe the clients, operation, and impact of the public HIV counseling and testing center. The men and women were of mean age 26-29 years in a range of 16-64 years. 16% overall were HIV-1-seropositive; 13% of men and 24% of women. 21% requested the HIV test in response to previous high-risk behavior, 20% felt sick, 18% were checking a previous HIV test result, 10% planned marriage or a new relationship, and 5% planned to have a baby. Heterosexual risk behavior was reported by 85% of clients, but only 1% reported male homosexual or IV drug use risk behavior. These behaviors were reported despite the existence among the sample of ample information about HIV transmission risks and AIDS prevention measures. An history of sexually transmitted disease, not using condoms, low education and salary levels, and being female were associated with HIV infection. Former negative HIV test results were associated with higher levels of condom use, while most clients expressed the intention to reduce their HIV risk behavior in response to either a positive or negative HIV test result. Most clients had caring attitudes toward people with HIV and AIDS. The authors note that sufficient demand exists for confidential HIV counseling and testing services in Thailand. Such services should be considered as a means of reducing HIV transmission in Asia, especially in areas of high HIV seroprevalence.