Each year, thousands of people suffer from malaria, the Zika virus, and other diseases transmitted by pests such as mosquitoes. However, humans may soon be in the clear, thanks to the drugs used to protect man’s best friend from fleas and ticks. In a new study, researchers found that fluralaner and afoxolaner, sold as Bravecto and Nexgard, respectively, effectively killed infectious mosquitoes and sand fleas when they consumed human blood laced with the compounds, according to Time. Through computer modeling, these researchers also found that if enough people took the drug, 97% of infections could be prevented in Zika-prone areas, and 70% of new malaria cases could be prevented in countries that experience seasonal malaria, they reported this week in the Proceedings of the National Academy of Sciences. To test these findings, researchers are already planning clinical trials in healthy human volunteers.