What happened Shares of the COVID-19 vaccine developers Dynavax Technologies (NASDAQ: DVAX), Ocugen (NASDAQ: OCGN), and Valneva (NASDAQ: VALN) are all making moves today. As of 1:32 p.m. EDT, Dynavax's stock was up 2%, Ocugen's stock was down 3.2%, and Valneva's shares soared 32% higher. What's driving these moves? The French biopharma Valneva announced this morning that late-stage trial results for its COVID-19 vaccine, VLA2001, produced a stronger overall immune response, with fewer side effects, when compared to AstraZeneca's shot. These results, in turn, are expected to form the basis for regulatory filings for Valneva's vaccine candidate in both the United Kingdom and the European Union. Image source: Getty Images. So what Dynavax's shares are moving higher on this news because Valneva's vaccine uses the biotech's adjuvant known as CpG 1018. An adjuvant is a compound used to boost a vaccine's efficacy. Dynavax thus stands to benefit financially from the vaccine's potential approvals overseas. Why is Ocugen's stock slumping on this news? Ocugen has a co-commercialization agreement in place with India's Bharat Biotech for a COVID-19 vaccine called Covaxin. Despite some recent successes on the regulatory front in India, the duo hasn't gotten key regulatory nods from either the U.S. Food and Drug Administration or the World Health Organization yet. While the news of Valneva and Dynavax's vaccine producing stellar late-stage trial results may not directly impact Ocugen at the end of the day, investors are apparently growing restless about Covaxin's regulatory fate in key developed and emerging markets. Now what Should investors buy shares of Dynavax, Ocugen, or Valneva on this news? Dynavax stands to take in over $200 million from its various licensing deals for CpG 1018, and today's news should shore up that revenue estimate. So, yes, Dynavax's stock might be worth picking up. Valneva's stock also comes across as a strong buy. The biopharma's market cap remains under $2 billion, and this vaccine could post sales in the hundreds of millions next year (assuming approval). Ocugen's stock, for its part, might also be a worthwhile buy on this pullback. The company has been stuck in neutral because of the slow progress with Covaxin's regulatory process. But this vaccine could play a key role in the fight against the pandemic. As a result, this small-cap biotech may be worth adding to your portfolio today. 10 stocks we like better than Ocugen, Inc.When our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now... and Ocugen, Inc. wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of September 17, 2021 George Budwell has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source