For more let's bring in ABC news medical contributor and its actions disease specialist doctor Todd Halloran director Todd. Good morning let's start with its changing vaccine we just turn wits peace the FDA's meeting tomorrow on possible emergency use authorization. And this scene is a single dose vaccine as opposed to and Daryn and finer Pfizer which required two doses. And the storage sneeze or little bit different so how an impact do you think this can have on trying to slow the spread of the virus. I think it is do you know going to have a massive impact what you said single dose double really decompress is truly just legal perspective getting that second dose within three of four weeks is really hard and on the company's parent should manufacture. Other please remember it doesn't require the freezer sorcerer it just requires refrigeration so does not only important in the United States but obviously remember this is a global effort and lastly because it's a viral type of vaccine. It allows for great scalability so all of those things are real problems. And there's also evidence now the new Colvin variant spreading right here in New York City and we're also seeing reports. Like California and Marion that may be more transmissible. Pfizer and Madeira now are exploring booster shots combat. At least one of those Newbury and how worried should we be about all of this. Oh well I mean obviously these periods are concerning right I. I think. What we're seeing is what we call conversion evolution is against you were presenting sort of survival of the fittest sourcing viruses that are competitive advantages where they can spread more efficiently so again concerning the good news is so far we've seen the vaccines look like they work to prevent severe infections as long as these parents are costing more hospitalizations. Icu admissions and deaths I think we're in good shape also. Important to the platform for these actions or opt in technology. To shut can shop so we can get a different vaccines there were able to cover these areas so again all of this is problems. And now that we could have a new vaccine coming soon get a little confusing right everyone wants the best to vaccine so is there any guidance on who should get what vaccine will what do you make of that. Rice or again remember the demand far exceeds the supply is the best vaccine right now is a one day you can roll up your sleeves and get us the most important thing all of them look like they help prevent against severe disease through major metro wonderful. And then. In terms of looking forward and daily cases are continuing to follow will hit the fifty million mark on how many people are vaccinated in this country today with at least one shot. So. Isn't this is not pretty more clarity on when we'll be able to return to political normal. So Diane he notes over 500000. Deaths in the United States ET ER. Aren't you know we've dropped our life span by one year OK we are witnessing really a national cemetery. We have the largest coal is cemetery in the world so is so important so when car urging that we're seeing so many millions of people Americans getting vaccinated every day but again we have to continue not just in our country but in the rest of the world in order really combat this is as fierce viral terrorist. Current doctors hot alar and it's always great to have you that if you don't have great news tourists think you. Teetered and.