The price of BioNTech shares traded on the NASDAQ exchange briefly fell by around $60, and stood at around $216 at the time of writing.

Some analysts tied the dramatic fall – which amounted to more than 20% – to the publication of an explosive report on the trials of the Pfizer-BioNTech Covid vaccine. Published in the British Medical Journal (BMJ) on Tuesday, the report cites a former contractor and claims to expose a staggering level of incompetence in management, the handling of data, and patient safety during the testing process.

The whistleblower, identified as Brook Jackson, claimed that the company hired poorly-trained vaccinators, that it was slow to investigate the adverse effects, and even falsified data on the trials. She also provided the BMJ with dozens of internal documents to substantiate her claims.

Another possible reason for the surprise stock plunge is said to be Pfizer’s announcement of the results for its Covid vaccine. On Friday, it cited trial data showing that its “game-changer” pill, Paxlovid, reduces Covid-19 hospitalizations by 89%.

The news came on the heels of Merck & Co, another US pharma company, announcing that clinical trials show that its own vaccine reduces the risk of hospitalization and death in patients with mild to moderate Covid-19 by 50%. Merck’s drug has since been approved for treatment of Covid-19 patients in the UK.

There has been media speculation that the emergence of Covid-19 drugs might have made investors believe that demand for vaccines would decline. Another vaccine developer, Moderna, took a $55 drop on Friday, and briefly stood at $229 before slightly recovering. Novavax shares fell as well.