Moderna, BioNTech plunge as Bernie Sanders slams 'obscene' profits and tells drug makers to share COVID-19 vaccines with the world

"It's time for these pharmaceutical companies to share their vaccines with the world and start controlling their greed," Sanders tweeted.

• Moderna and BioNTech plunged more than 16% on Monday amid a critical tweet from Senator Bernie Sanders.
• Sanders highlighted the surge in the companies' stock prices after the Omicron variant was identified.
• "It's time for these pharmaceutical companies to share their vaccines with the world and start controlling their greed," Sanders tweeted.

Shares of COVID-19 vaccine makers Moderna and BioNTech plunged as much as 16% and 20%, respectively, on Monday amid a highly critical tweet from Vermont Senator Bernie Sanders.

Sanders took issue with the surge in the companies' stock prices after a new COVID-19 variant named Omicron was identified in late November. Shares of Moderna soared as much as 35% following the Omicron news, while BioNTech, which partnered with Pfizer to distribute its COVID vaccine, jumped as much as 19%. 

The higher stock prices can mostly be attributed to investors belief that the vaccine makers will have a longer than expected runway ahead as it works to help eradicate the COVID-19 pandemic and its variants. On top of that, fears of Omicron have helped drive a surge in booster shots and new vaccinations in recent weeks.

But Sanders views the windfalls the companies and their investors have reaped as "obscene", calling for the companies to share their vaccines with the rest of the world.

"This is obscene. Last week, 8 investors in Pfizer and Moderna became $10 billion richer as news about the Omicron variant spread. It's time for these pharmaceutical companies to share their vaccines with the world and start controlling their greed. Enough is enough!" Sanders tweeted Sunday evening.

That tweet, combined with growing anecdotal evidence that Omicron is less deadly than prior COVID-19 variants, led to a swift decline in the drugmakers stock prices on Monday. Pfizer fell as much as 5% on Monday as well. 

Moderna and Pfizer have made their vaccines available to countries other than the US, though there have been mounting criticisms that poorer nations are near the end of the vaccine line as the vaccine makers focus on generating profits by selling the vaccines to richer countries for a higher price. 

The decline on Monday wiped out all of the gains and then some since news of the Omicron variant was announced in late November. BioNTech and Moderna are now down 8% and 5% since the Thanksgiving holiday in late November, highlighting the extreme volatility seen biotech companies that are reliant on a single product for their financial success.