Three years after the mysterious MERS virus first emerged in humans, and as South Korea reports its 19th death in the current outbreak, scientists and drugmakers say there is no excuse for not having a vaccine that could have protected those now falling sick and dying.
South Korea's health ministry reported four new cases of Middle East Respiratory Syndrome (MERS) on Tuesday, bringing the total to 154 in an outbreak that is the largest outside Saudi Arabia. The ministry also said three patients infected with the MERS virus had died, taking the death toll to 19 in an outbreak that began in May.
The facts behind the coronavirus that causes MERS have been slow to emerge, partly due to a secretive response in Saudi Arabia, which has suffered an outbreak stretching back to 2012.
But scientists do know that it is similar to the deadly SARS virus, that it probably originated in bats, that it is linked to camels, and can pass from person to person. They also understand its molecular structure.
That all yields scientific detail for researchers to begin developing a vaccine, and there is clear frustration that work on one has barely begun.
The problem is that big pharmaceutical firms are uncertain about the economics of such a vaccine and no governments have yet offered to underwrite a major research effort.