Drugmakers and health officials say we won't know for a few weeks just how bad the omicron variant will be, particularly in regard to the current vaccines. In the meantime, sentiment is seesawing, as reflected in world financial markets. Friday was grim, Monday rebounded, and now Tuesday is shifting back into gloomy territory. Dow futures were poised to drop more than 1%, or about 400 points, at the market open, reports the Wall Street Journal, and that's on the heels of poor performances by Asian and European markets. Driving the negative sentiment appear to be comments from the CEOs of Moderna and Pfizer suggesting that current vaccines won't be as effective against the variant.