NEW YORK ( TheStreet) -- Welcome back to another Biotech Stock Mailbag. Joe P. emails, "Just curious to know what your take is on Dynavax's (DVAX) Heplisav. I feel a lot of blogs and even Twitter have been preoccupied with other names lately, though the Heplisav PDUFA is steadily approaching. I find it interesting the journey this vaccine has taken from a clinical trial hold, to Dynavax proposing an indication of patients aged 40-plus but then the FDA expanding it to patients 18-plus, then the negative advisory committee vote and now the PDUFA. Has there ever been a negative safety advisory committee vote that progressed to an FDA approval? I read the negative safety vote as a wild card: It was a close vote and the actual discussion was in my opinion off topic and based on theoretical risks of a novel adjuvant." The FDA approval decision date -- the PDUFA -- for Dynavax's Heplisav hepatitis B vaccine is Feb. 24. I predict approval. The FDA may place some restrictions on Heplisav initially -- patient age or other risk factors -- but those could be lifted once Dynavax submits additional clinical data in hand already. (No new clinical trials are necessary.) Last November's advisory committee meeting wasn't as bad as the headlines suggested. Remember, the panel strongly supported Heplisav's efficacy. The vaccine works. On the safety question, the panel voted 5-8 against but only due to theoretical concerns about rare side effects that might appear in some patients. To me, this was just busting chops for the sake of busting chops. I hope (expect) FDA won't be nearly as shortsighted. At the J.P. Morgan Healthcare Conference last month, Dynavax executives told investors that it was in discussions with FDA about the Heplisav review. This may or may not have included submission of additional data for the agency to review. FDA could have easily extended the Heplisav review period by three months. The fact that the approval decision date is still set for Feb. 24 suggests to me that agency has the data it needs and that approval is more likely than a rejection. The risk to being bullish on Heplisav's near-term approval: Heplisav is not an unmet medical need. Other hepatitis B vaccines are already on the market, so the sense of urgency for FDA to approve is missing. Dynavax shares shouldn't drop too far on a Heplisav rejection as long as the only requirement for resubmission is clinical data the company already has compiled. Worse case is FDA asking for an entirely new clinical trial, but that seems very unlikely. Bill W. writes, "Hi, Adam, your sharp reporting got me safely out of Cel Sci (CVM), and I wish I had listened to you on that piece of $%^@ Generex (GNBT). Now, I would really appreciate your view on ImmunoCellular Therapeutics (IMUC), which had a nice pop. Is ImmunoCellular of the same shyster ilk as those other two?" No, ImmunoCellular is not as stinky as Cel-Sci or Generex, but that doesn't make me a fan, either. The relevant question to ask about ImmunoCellular is this: Are you a trader or an investor? If you're the former, then by all means pay attention to ImmunoCellular and its brain tumor vaccine ICT-107 because every three to six months, the company seems to be promoted heavily to retail investors as the next great cancer vaccine stock. Naturally, these promotional efforts lift the stock price. Sometimes, ImmunoCellular takes advantage by raising money, sometimes it doesn't. Once the buzz fades -- and it always does -- ImmunoCellular's stock price falls.