Key Takeaways Vaccine stocks fell after an FDA memo cited child deaths and outlined tougher vaccine requirements.The memo flagged myocarditis concerns, stricter data demands and limits on use in pregnancy.An upcoming CDC meeting on vaccine safety and necessity added to pressure on MRNA and peers.Shares of prominent vaccine makers Moderna (MRNA) , BioNTech (BNTX) , Pfizer (PFE) , Novavax (NVAX) and Vaxcyte (PCVX) fell on Monday after the FDA announced plans to impose strict new vaccine requirements.What’s Go ...