british, 1,400 japanese, 700 canadians, 250 irish, and 115 iraqis. infection via the tainted factor products had mostly stopped by 1986 by which time viral inactivation methods had largely been put into place, although some products were shown to still be dangerous in 1987. research gene therapy in those with severe haemophilia, gene therapy may reduce symptoms to those that a person with mild or moderate haemophilia might have. the best results have been found in haemophilia b. in 2016 early stage human research was ongoing with a few sites recruiting participants. in 2017 a gene therapy trial on nine people with haemophilia a reported that high doses did better than low doses. it is not currently an accepted treatment for haemophilia. in july 2022 results of a gene therapy candidate for haemophilia b called flt180 were announced, it works using an adeno-associated virus (aav) to restore the clotting factor ix (fix) protein, normal levels of the protein were observed with low doses of the therapy but immunosuppression was necessitated to decrease the risk of vector-related immune responses.