This vaccine maker is targeting RSV (respiratory syncytial virus), which afflicts roughly 3 million babies and elderly people each year, leading to an estimated 66,000 deaths. Longer term, Novavax is also pursuing vaccines for the herpes, bird flu and even the seasonal flu viruses.

The recent swoon in biotech stocks, which I discussed last week, has taken this stock down with the group. In response, a group of four insiders recently acquired nearly $300,000 in stock at an average price of $4.30 a share.

Biotech investors should always be concerned about cash balances, just in case further access to capital is hard to accomplish. Thanks to a secondary share offering in 2013, Novavax has $130 million in the bank, which will come in handy as this firm is in the midst of several costly clinical trials.

To be sure, no vaccine has advanced beyond Phase II at this point, so it will likely be several years before any vaccines come to market -- but clinical trial updates later this year could help breathe new life into shares.

MLV Capital sees shares rising more than 200% to a $14 price target, noting that peak annual sales could approach $2 billion a decade from now if these vaccines prove to be successful. (MLV estimates the flu vaccine program is worth $9 a share all by itself.)

This company first came on many investors' radars a year ago when it was recognized as an emerging early-stage biotech by the World Vaccine Congress. Inovio is developing DNA-based vaccines, which have a different mechanism of action than most vaccines, which typically work by spiking the body with live (or neutered) viruses.

The unique technology has led Inovio to take the platform approach, as roughly 10 different vaccines (targeting influenza, malaria, HPV and others) are all being developed on what the company calls a Synthetic Consensus. SynCon, as it's known, takes a section of DNA to produce cells that are directly targeted at virusues through a process known as electroporation.

Drug giant Roche Holding (Nasdaq: RHHBY) signed a deal with Inovio in September to jointly support vaccines targeting prostate cancer and hepatitis B. Though the deal brought a modest $10 million in upfront payments to Inovio, it could be worth more than $400 million if milestones are met.

To be sure, recent capital raises have boosted the share count to 240 million, implying a market value that already has hit $800 million. And investors should know that DNA-based vaccines have had a hard time successfully completing all phases of clinical trials. So this stock carries ample risk, but the market value would move into the billions if the SynCon platform eventually generates FDA-approved vaccines.

I profiled this vaccine maker back in September, and shares soon doubled in value -- and then gave up all of those gains, as bloggers on Seeking Alpha suggested that the company's vaccines were more hype than reality. (You can read those concerns here and the company's response here.)

Simply put, it's too soon to know if NanoViricides' vaccines will succeed. Beyond the short sellers' allegations, the early-stage nature of clinical trials means that the hardest hurdles are yet to come. And this small company will surely need to raise more capital as its trials progress. But it's important to remember that Inovio was seen in a similarly dubious light, and that company has managed to defy the shorts with meaningful progress. So NanoViricides is worth monitoring as you focus on stocks with potential blockbuster vaccines.