The Complidon survey, launched in late 2017—one year after blood donation was opened up to MSM—is the first French study to measure non-compliance with blood donor selection criteria. This survey, to which nearly 110,000 donors responded, demonstrated in particular that contraindications for blood donation are not always strictly adhered to. Thus, 0.73% [95% confidence interval (CI): 0.63–0.83] of men reported having had sex with men in the 12 months prior to their last donation, without having disclosed this during the pre-donation interview.

With a view to changing the selection criteria regarding MSM, Complidon also estimated that 46% of MSM would have reported having had sex with men if the deferral period had been shorter, and that 0.56% of men had had sex with men in the four months prior to their donation.

At the same time, epidemiological surveillance of blood donors showed that the risk of HIV transmission through transfusion remained completely stable, and at a very low level, during the two 30-month periods preceding and following the opening of blood donation to MSM in July 2016.

The results from Complidon and the blood donor surveillance thus helped inform public health authorities’ decisions regarding eligibility criteria for MSM to donate blood.

In response to the government’s intention to revise the screening criteria for MSM, two scenarios were examined. The first scenario involved reducing the deferral period from 12 to 4 months, and the second called for aligning the criteria with those for all donors, namely having a single sexual partner during the 4 months prior to donation.

The impact of the two scenarios on the residual risk of HIV transmission through transfusion was assessed based on three surveys conducted by Santé publique France (2016 Health Barometer, 2017 Sex Survey, and 2017 Complidon), in order to estimate, on the one hand, the number of additional MSM likely to donate blood under each scenario and, on the other hand, the incidence of HIV among these additional MSM donors.

Regardless of the scenario studied, the residual risk associated with HIV remains very low. However, while in the first scenario the residual risk remains exactly the same as that observed for a 12-month deferral of MSM, in the second scenario it is 1.5 times higher, and the sensitivity analysis shows that the estimate is less robust to variations in the parameters used in the model used to estimate this risk. In July 2019, based on these results, the Minister of Health opted for the first scenario, which will take effect on April 2, 2020.

Similar risk analyses have recently been conducted in certain countries. In 2016, in the United Kingdom, the SaBTO (Safety of Blood, Tissues and Organs) advisory committee assessed the risk of HIV transmission through transfusion in the event of a reduction in the deferral period from 12 to 3 months for MSM. As in France, no increased risk was identified with this new criterion, which was therefore implemented in that country as of November 2017. Similarly, in Canada, a 3-month deferral period for MSM was introduced on June 3, 2019, following a similar analysis that showed no increased risk to transfusion safety.

This change in criteria has been considered by the Ministry of Health, as it is a scenario we were asked to examine as part of the risk analysis. Before moving forward with this final step, the Ministry would like an assessment of a 4-month deferral for MSM, a new criterion implemented on April 2, 2020. This evaluation will consist of an estimate of the residual HIV risk over the 2020–2022 period and the implementation of a new survey, modeled after Complidon, to measure MSM donors’ compliance with this new criterion. A residual HIV risk that does not increase and improved compliance with the new criterion will be positive indicators that will make it possible to consider this change.

Other countries, such as the United Kingdom, Canada, Australia, the United States, and others, are considering adopting selection criteria independent of sexual orientation. However, for these countries, no risk assessment regarding the alignment of the MSM criterion with that of other donors has, as of yet, been published.