I WAS shocked to read that the Secretary of Health and Welfare, Elizabeth Wong Chien Chi-lien, was critical of government-produced AIDS warnings being shown in Hong Kong (''Televised AIDS warnings 'spread discrimination' '', South China Morning Post, March 18). She apparently feels that these public-service spots will promote discrimination against AIDS sufferers, and cause unnecessary fears among the viewing public. What utter nonsense! My husband and I commented just the night before, after viewing the ad depicting the young expectant couple where the husband learns his ex-girlfriend has AIDS, how very poignant and effective this campaign is. This is a tasteful, meaningful and realisticdramatisation of the importance of careful testing to protect your loved ones; and the fact that your sexual past can and sometimes does impact your future and the future of others. The other ad which has been criticised is the one depicting the young woman (teenager) learning that someone she knows has AIDS. It is implied that she was sexually involved with him. Again, a realistic portrayal of a scenario of which all young people should be aware and mindful. The concluding message of both ads is ''it could happen to you''. Isn't this exactly what people must be told - young people in particular? In what way is discrimination promoted in either of these messages? In terms of prevention, there can be nothing more valuable than to make people aware that AIDS can indeed happen to them, and to educate them as to how it can happen. Yes, it can happen to heterosexual men and women - whether teenaged or adult. Yes, other people can be hurt by your careless behaviour. The message that ''it can happen to you'' will reduce discrimination against victims, not promote it. Discrimination arises from an attitude of ''this is not me'', not one of ''this could be me''. Surely Ms Wong and her colleagues at Health and Welfare should be able to understand that simple and obvious concept. LESLIE FRAPPIER Ap Lei Chau