Yes. Doxycycline has been available since 1991 at least, because that's when Pfizer licensed it. Potentially, it was an anti-malaria drug that could have been used in the nineties. In 1997, there was an important randomized controlled trial, which Professor Libman has referred to as being the “gold standard” of evidence, conducted in soldiers in Indonesia by an U.S. Army research team. This found that it was extremely effective at preventing malaria. The efficacy was 99%.
The tolerability of it was excellent as well.