single dose vaccine. the fda just said it can be stored for 4 1/2 months. that's 6 weeks longer than previously allowed. the news comes days after ohio warned some 200,000 j&j shots would soon expire. and wolf, just one other note on that johnson & johnson vaccine. a member of j&j's board, dr. mark mcclelen, telling cnn today the reasons they don't know how long this vaccine can be stored is because frankly everything's happened so quickly as part of this emergency, but he did say those studies are ongoing. >> let's discuss all of this with a key member of the fda's vaccine advisory committee. he was in today's meeting. dr. paul offit, thanks so much for joining us. take us inside the deliberations today. are you confident that american children under the age of 12