What happened

Shares of Moderna (MRNA -0.53%) fell by almost 6% on Tuesday. While the company's mRNA-1273 remains one of only two coronavirus vaccines authorized by the Food and Drug Administration, its counterpart seems to be the one getting all the positive press lately.

So what

The yang to mRNA-1273's yin is BNT162b2 from Pfizer (PFE -1.62%) and German biotech BioNTech (BNTX -0.49%).

On the back of research indicating that the BNT162b2 vaccine can be stored for up to two weeks at lower temperatures than previously anticipated, the FDA on Tuesday approved it to be stashed in standard freezer environments. Previously, only ultra-cold storage was deemed appropriate.

Man receiving a vaccination shot.

Image source: Getty Images.

This means that the shipping and storage requirements for BNT162b2 will be much less burdensome (at the moment, due to the ultra-cold limitations, it also has to be transported in specialized containers).

Combined with other research indicating that the Pfizer/BioNTech vaccine is highly effective after just one dose, this makes BNT162b2 a much more compelling option in an environment where mass inoculations are required, and required yesterday.

Now what

But we shouldn't lose sight of the fact that Moderna's vaccine never required ultra-cold storage. Like BNT162b2, it's also been shown to be extremely effective; no wonder the U.S. government last week ordered 100 million additional doses of it.

Moderna's jab will continue to be instrumental in the fight against the coronavirus, so investors shouldn't be discouraged about the company's prospects.