Moderna, BioNTech tumble 19% amid report the EU is looking into COVID vaccine side effects

Stephen Zenner/SOPA Images/LightRocket via Getty ImagesModerna and BioNTech shares fell sharply Wednesday due to reports that the European Union is investigating possible side effects of their COVID-19 vaccines.The agency is investigating possible side effects of the drug on the skin and kidneys.Moderna was further removed from Monday's closing high, and the $200 billion market capital it reached that day.Check out more stories from Insider's business page.Following a report by the European Union's drug regulator, shares of BioNTech and Moderna fell sharply on Wednesday. This was due to reports that potential side effects from their respective COVID-19 vaccines may have been investigated.Wednesday's announcement by the European Medicines Agency stated that it began evaluating reports regarding skin and kidney conditions following vaccinations with Comirnaty. This vaccine was developed by Pfizer, BioNTech and Spikevax. Reuters reported the notifications from the agency.Moderna shares and US-listed shares in Germany-based BioNTech fell as high as 19%. Moderna's stock fell further from Monday's record high. Pfizer shares dropped 4% to intraday lows.Although the EMA stated that there were "a few cases" of potential side effects, it did not specify how many.The Agency's Pharmacovigilance Risk Assessment Committee is trying determine if Erythema Multiforme, an allergic reaction that causes round skin lesions, glomerulonephritis (inflammation of the tiny filters in your kidneys), and nephrotic Syndrome are side effects. Nephrotic syndrome refers to a condition that causes too much protein in the urine."Further analyses and data have been requested from marketing authorisation holders to support the ongoing evaluation," the agency stated in each notice.Moderna shares surged 17% Monday to close at a record high. This was partly due to its coronavirus vaccine being approved for use in Australia and Switzerland. Moderna's value climbed to near $200 billion Monday due to a huge rally of over 360% throughout the year. Moderna's valuation was more than Merck, a drug and vaccine company.Bank of America stated in a Tuesday note that the valuation was "unjustifiable from a fundamental basis". Bank of America reiterated its $115 target price, which was a potential downside of 76% compared to Monday's close. Moderna stock dropped by 5.7% Tuesday.