This is a question that will be addressed in risk assessment (see How to manage risks?). Risk assessment will take into account what other diseases that can be transmitted by the target mosquito species are present in the region where the gene drive-modified mosquitoes will be released. If necessary to support risk assessment, experiments can be conducted in the laboratory to measure the ability of the gene drive-modified mosquitoes to transmit different pathogens. Such experiments involve artificial feeding on blood containing the pathogen, using a membrane feeding device, and then examining the ability of the pathogen to grow in the mosquito and/or to be ejected in the mosquito’s saliva as might happen when it bites.
For more information: https://www.youtube.com/watch?v=nfZrSH7uQ08; https://www.who.int/publications/i/item/9789240025233;