Science Developing more broadly protective products requires comparisons with existing shots that Pfizer and Moderna won’t allow.
The U.S. government has tens of millions of unused doses of messenger RNA (mRNA) COVID-19 vaccines, regularly trashing shots as they pass their expiration dates. It’s a dismal reflection on recent vaccine uptake, but it’s also a serious roadblock for scientists testing and developing vaccines that could protect against future variants of SARS-CoV-2—and the next pandemic. Developers need existing vaccines as a benchmark to compare with new candidates. But government contracts with the vaccinemakers, and the companies’ own policies, prohibit the use of the vaccines for research purposes.
“At this stage of the game, with millions of vaccines on the verge of being thrown away, this seems crazy,” says Nicole Lurie, U.S. director of the Coalition for Epidemic Preparedness Innovations (CEPI). The situation is so dire that one startup has created mimics of the mRNA vaccines in use to help researchers improve their formulations.
Most researchers working on next-generation vaccines hope to create products that stimulate broader immunity to protect people from all sarbecoviruses, a group that includes variants of SARS-CoV-2, SARS-CoV-1, and related viruses found in bats and other wild animals that might spill over to humans. As part of the development process, researchers want to compare their candidates in animal models to the proven Moderna and Pfizer mRNA vaccines. They want to see how immune responses to the candidates stack up to the responses generated by current shots. They also want to give animals the existing and experimental vaccines and “challenge” them with different SARS-CoV-2 variants.
CEPI, which aims to speed the development of vaccines, has invested $230 million in 13 such vaccine candidates. The National Institute of Allergy and Infectious Disease (NIAID) has committed nearly $60 million to seven other academic teams working on what’s called pancoronavirus vaccine development, which has similar goals. Four groups receiving support from either CEPI or NIAID told Science that long-existing difficulties obtaining comparator vaccines has slowed their progress. “The acquisition of those direct comparators has been very difficult and challenging,” says In-Kyu Yoon, a CEPI director.
Neither NIAID nor the Biomedical Advanced Research and Development Authority, which purchased and distributes the Pfizer and Moderna vaccines, responded to Science’s questions.
The original efficacy trials of the Pfizer and Moderna mRNA vaccines compared those vaccines to placebo shots. But when those products received emergency use authorizations in December 2020, they became the standard of comparison in any future efficacy trials. The initial push for comparators came from developers who had COVID-19 vaccine candidates based on technologies other than mRNA, such as viral vectors or nasal delivery.