Covid-19 vaccine collaborators Pfizer and BioNTech are attempting to invalidate two patents owned by their rival Moderna that they were accused of infringing last year.

In petitions to the US Patent and Trademark Office’s Patent Trial and Appeal Board (PTAB), they said that Moderna obtained the patents at issue during the pandemic with “unimaginably broad claims directed to a basic idea that was known long before the asserted priority date of 2015”.

The claims cover the composition and administration of an mRNA vaccine encoding any spike protein or spike protein subunit of any betacoronavirus (whether in existence or arising at any later point in time), formulated in a lipid delivery system. The petitions state that the patents' broad claims encompass subject matter disclosed in the art before 2015, the earliest date to which the patents in dispute claim priority.

Pfizer and BioNTech request that the challenges claims be found unpatentable and cancelled.

Pfizer, along with its German partner BioNTech, developed the Covid-19 vaccine know as Comirnaty, which is based on BioNTech’s proprietary mRNA technology and was developed by both it and Pfizer.

There has been a rash of lawsuits relating to mRNA Covid-19 vaccine technology. In this one Moderna fired the first arrow in August 2022, filing patent infringement lawsuits against Pfizer and BioNTech in a number of different jurisdictions, including a federal court in Massachusetts and in Germany.

Moderna said at the time that it believes that Pfizer and BioNTech's Covid-19 vaccine Comirnaty infringes patents it filed between 2010 and 2016 covering its foundational mRNA technology. This groundbreaking technology was critical to the development of Moderna's own mRNA Covid-19 vaccine, Spikevax.

Pfizer and BioNTech responded in December in the US by countersuing and demanding a jury trial.

In the PTAB challenge Pfizer is being represented by David Krinsky and Stanley Fisher of Williams & Connolly. Meantime BioNTech is represented by Paul Hastings' Naveen Modi, Bruce Wexler, Eric Dittmann, Chetan Bansal, Rebecca Hilgar and Ryan Meuth.