COVID-19 vaccine maker Moderna is suing Pfizer and the German drugmaker BioNTech, accusing its main competitors of copying Moderna鈥檚 technology in order to make their own vaccine.

Moderna said Friday that Pfizer and BioNTech鈥檚 vaccine Comirnaty infringes on patents Moderna filed several years ago protecting the technology behind its preventive shot, Spikevax. The company filed patent infringement lawsuits in both U.S. federal court and a German court.

Pfizer spokeswoman Pam Eisele said the company had not fully reviewed Moderna鈥檚 lawsuit, but the drugmaker was surprised by it, given that their vaccine is based on proprietary technology developed by both BioNTech and Pfizer.

She said in an email that the company would 鈥渧igorously defend鈥� against any allegations in the case.

BioNTech did not immediately respond to a request from The Associated Press seeking comment.

Moderna and Pfizer鈥檚 two-shot vaccines both use mRNA technology to help patients fight the coronavirus.

The mRNA vaccines work by injecting a genetic code for the spike protein that coats the surface of the coronavirus. That code, the mRNA, is encased in a little ball of fat, and instructs the body鈥檚 cells to make some harmless spike copies that train the immune system to recognize the real virus.

That approach is radically different than how vaccines have traditionally been made.

Moderna said it started developing its mRNA technology platform in 2010, and that helped the company quickly produce its COVID-19 vaccine after the pandemic arrived in early 2020.

By the end of that year, U.S. regulators had cleared shots from both Pfizer and Moderna for use after clinical research showed that both were highly effective.

Moderna CEO Stephane Bancel said in a prepared statement that the vaccine developer pioneered that technology and invested billions of dollars in creating it.

The company said it believes its rivals鈥� vaccine infringes on patents Moderna filed between 2010 and 2016.

Moderna said it recognizes the importance of vaccine access and is not seeking to remove Comirnaty from the market. It also is not asking for an injunction to prevent future sales.

Moderna said in 2020 that it would not enforce its COVID-19 related patents while the pandemic continued. But the company said in March, with vaccine supplies improving globally, that it would update that pledge.

It said it still would not enforce its patients for vaccines used in low- and middle-income countries. But it expected companies like Pfizer and BioNTech to respect its intellectual property, and it would consider 鈥渁 commercially reasonable license鈥� in other markets if they requested one.

鈥淧fizer and BioNTech have failed to do so,鈥� Moderna said in a statement.

鈥擳om Murphy, The Associated Press