In its report on world aids day 2020, the joint united nations programme on hiv/aids (unaids) noted that the majority of new hiv infections globally (about 62 per cent) occur among key high-risk populations and their sexual partners, and that prevention of high-risk populations is an important link that cannot be ignored。
More than 90% of prevention effectiveness before exposure
Hiv prevention strategies are divided into behavioural and biomedical interventions, including partner education, needle exchange, promotion of condom use, and biomedical interventions covering treatment for sexually transmitted diseases, mother-child disruption, treatment or prevention (tasp), pre-exposure prevention (prep) and post-exposure prevention (pep)。
According to professor wangning: “in recent years, there has been a growing emphasis on pre-exposure prevention (prep) and post-exposure prevention (pep) in international preventive and control practice. However, it needs to be emphasized that prevention before exposure is the key to hiv prevention. Pre-exposure prevention refers to the use of specific anti-viral drugs by persons who have not been infected with hiv prior to the occurrence of hiv-prone behaviour in order to prevent hiv infection, an approach that can be effective if it is used, can significantly reduce the risk of hiv through sexually transmitted infections and can provide effective prevention for those at higher risk of hiv infection. The principle of pep against hiv infection is to limit the reproduction of hiv into the human body after entry through the early use of anti-hiv-infected drugs, thus achieving the effectiveness of preventing hiv infection, which, in a highly dependent manner, can be more than 90% effective against hiv infection before exposure.”
These people are suitable for pre-exposure prevention
China's first pre-exposure preventive drug for the uninfected population, entraitham, was approved in august 2020 for pre-exposure prophylaxis for people at higher risk of hiv infection, with a view to reducing the risk of hiv infection among adults and adolescents. The groups recommended for the use of prep include men who have sex with men (msm), heterosexuals who are at high risk of contracting hiv virus, and hiv-negatives among hiv-positive couples。
Pre-exposure prevention is not a vaccine and the body does not produce an anti-hiv body and therefore requires regular use to achieve its prevention effect. Professor zhang fokjie, an infecting centre attached to beijing ground hospital, stated that the effectiveness of prep in preventing hiv infection was highly dependent on drug dependence, and that the greater the dependence on prep drugs, the better the effect of reducing the risk of new hiv infections。
It should be recalled that, as an effective means of preventing hiv, the prep is not capable of preventing other sexually transmitted diseases, and therefore the promotion of treatment among high-risk groups is a comprehensive prevention strategy for prevention, pre-exposure prevention and condom use。
