Don’t call it a comeback: Novavax just (briefly) became a meme stock.

The Maryland-based biotech joined the likes of Ango American, Vodafone and the notorious GameStop in a resurgence of the meme stocks craze from early 2021.

Novavax shares jumped nearly 100% on Friday and another 50% on Monday following its announcement last week that it struck a new partnership with Sanofi.

Under the licensing agreement, Sanofi will pay Novavax $500 million upfront with up to $700 million in milestone payments, making the deal worth up to $1.2 billion. 

The agreement also gives Sanofi rights to sell Novavax’s COVID-19 vaccine and permits the French pharma giant to work with Novavax in developing new flu-COVID combination vaccines.

News of the deal pacified investor worries as it allowed Novavax to remove its “ongoing concern” warning, which it had originally issued last year after struggling to continue operating amid plummeting COVID-19 sales.

Novavax CEO John Jacobs told CNBC that the deal helps the business and “keeps us well capitalized.” He noted that the Sanofi partnership also gives Novavax the chance to pivot its strategy more toward “what we’re best at” and provide additional value to shareholders.

Meme stocks, which gained notoriety in early 2021 during the GameStop short squeeze, refer to situations where a company’s shares skyrocket due to viral social media hype around them. 

In the last few days, the return of trader Keith Gill — otherwise known as “Roaring Kitty” — to X, the social media platform formerly known as Twitter, spurred the resurgence of so-called meme stocks.

Some of those original meme stocks, including GameStop and AMC, jumped more than 70% Monday and continued to rally throughout the trading session Tuesday.

Novavax experienced a short squeeze as a result of Sanofi news as well as the broader market comeback, which involves short sellers quickly buying up shares to close out their positions, which in turn drives stock upwards.

For Novavax, the Sanofi deal is a welcome one. After falling behind vaccine trailblazers like Pfizer, Moderna and Johnson & Johnson in the race to develop a COVID-19 vaccine, Novavax has since struggled to stay afloat as the pandemic fades into the rear view mirror.

Leerink Partners analyst David Risinger told CNBC that the firm expects Sanofi to drive greater commercial success of Novavax’s vaccine starting next year, due to its commercial scale and contracting abilities, but added it is “difficult to predict the magnitude of impact.”