The good news is, an Ebola test from Roche Holding Ltd. (ADR) (RHHBY) was just approved by U.S. regulators for emergency use. The bad news is, that fact is largely irrelevant at this point.

Not only has the upside of Ebola stocks run its course now that the contagion has been mostly contained, but the Roche test in question may prove relatively useless.

In short: RHHBY shareholders need not get too excited about the seemingly compelling headlines.

Add Roche to the List of Ebola Stocks, But…

The LightMix Ebola Zaire rRT-PCR Test — made by TIB Molbiol and exclusively marketed by Roche — has gotten the green light from the Food & Drug Administration to use as a screener for the disease in the United States, putting the company into the mix of Ebola stocks that have been jockeying to capitalize on the deadly outbreak of the disease.

The test produces results in roughly three hours … but there’s a catch.

The LightMix Ebola Zaire rRT-PCR Test can only be performed by certain diagnostic laboratories, and is only useful for patients exhibiting early signs and symptoms of the Zaire strain of the Ebola virus… the one that started to spread out of control in September. Specifically, the diagnostic process can only be performed b CLIA High Complexity Laboratories that employ Roche’s LightCycler 480 or Cobas Z 480 instruments, and for detection to be possible the virus must have already spread to the bloodstream, where it becomes inherently difficult to stop its spread.

To give credit where it’s due, the TIB Molbiol test is much faster and can be more accurate than current alternatives. For example, one Ebola test looks for antibodies already produced by a patient’s immune system that would only appear if the virus were present. This approach presents a problem, though, in that it can take three or more days to find a positive result once a potentially infected patient has been tested. That individual could infect others before being determined to be infected.

The Roche test also could be advantageous over what’s considered to be the benchmark of Ebola tests currently being utilized … the polymerase chain reaction (or PCR) test, which can detect pieces of the virus’ RNA itself.

Some sensitive polymerase chain reaction tests can detect the virus as early as two days before symptoms start to appear, but only if there’s enough virus in the blood to detect at the time of testing. A mistimed test could imply an in infected individual is safe when he or she really isn’t, so such a test would need to be run twice a day for several days in a row. Although most PCR tests are affordable once and some can yield results in less than a day, running multiple tests can become costly, and even then PCR tests aren’t 100% accurate.

The LightMix Ebola Zaire rRT-PCR test from Roche is a polymerase chain reaction test that is faster than the alternatives, and presumably more accurate than other PCR tests in use given the sensitivity of the equipment required to perform the diagnostic test. Again, though, the equipment needed to perform the test is relatively rare, and not found at most hospitals or state-based public health departments.

Bottom Line for RHHBY

There’s no doubt that this morning’s announcement from Roche adds it to the list of Ebola stocks that could benefit from the outbreak. At this point in time, however … so what?

There are a minuscule number of suspected cases coming into the U.S. now that containment efforts are taking hold, and even with a small surge of new cases being detected in Liberia this weekend, U.S. Ebola czar Ron Klain was recently quoted as saying the outbreak was reaching a pivot point, suggesting we could start to see a contraction in the number of infected patients soon.

Indeed, the recent action from other Ebola stocks suggests the hype needed to catapult these tickers higher has already been exhausted. Tekmira Pharmaceuticals Corporation (TKMR), which developed a viable treatment for the disease, has seen its stock fall 55% after peaking in October at the height of the Ebola frenzy. Meanwhile, haz-mat suit maker Lakeland Industries, Inc. (LAKE) has seen its shares fall nearly 70% after also peaking in October at the height of Ebola-mania. Neither stock seems willing or able to rekindle their rallies.

With their former fervor unlikely to be repeated for Ebola stocks again — now that the disease is abating — it’s unlikely RHHBY is going to experience any real benefit from today’s announcement regarding its PCR test.

As of this writing, James Brumley did not hold a position in any of the aforementioned securities.