Ebola mixed with something much worse!

This is book 1 of a 5 book series. I will totally be continuing this series! We start out with a team of soldiers in Vietnam who were part of a secret bioweapen project (not that they knew they were a part of it). They take this experimental pill and basically go nuts. They turn into violent killing machines. It’s such a huge failure, they scrap the “super soldier” program.
Thirty years later, an elite army team embarks on a mission that sounds shady. A higher up (my military knowledge is not great!) sends the team to a secret research island for a sample of a potential cure to a new strain of Ebola that’s raging through Africa.
What they encounter is out of a horror movie. There are bodies everywhere, ripped to shreds, and super dead. Then they engage with the ones who are still alive. They’re much worse. They start hunting & killing the team. Only half of the soldier team comes back alive. The men think the nightmare of that island is over, but of course it’s not.
One of the scientists got onto a plane headed for Chicago right before shit started going down on the island. He didn’t know he was infected.
Long story short, the bioweapen project merged Ebola with the super soldier drug, & created super virulent, super violent Ebola monsters. It’s basically the worst of two terrible things.
The infection spreads and turns into a pandemic that sweeps the country & eventually the globe. A small group of people on another secret island works on a cure…
Cue book 2!