In what way are the progeny of OX513A rendered benign in terms of their threat to humans?

The strain OX513A has been genetically modified to express a marker gene (red fluorescence) and a repressible lethal trait, resulting in a phenotype where male Aedes aegypti released with the genetic construct will pass on the lethal trait to both male and female offspring, causing them to die as larvae or pupae. No toxic proteins, plasmid backbone sequences, antibiotic resistance genes, insecticide genes or bacterial origins of replication have been introduced into the OX513A strain of mosquitoes.