Transcript for COVID-19 emergency across the US
Despite warnings from the CDC to stay home millions of Americans have already traveled three US airports this weekend ahead of the Thanksgiving holiday. The US has a record 83000. People currently hospitalized with coded nineteen. Now some experts are warning us to look at Canada as a cautionary Thanksgiving tale. Their Thanksgiving is very similar to ours but Canada celebrates in October. Since then the country's daily cases have more than double. Infectious disease specialist doctor Todd Halloran joins me now with more on this doctor I'm good afternoon what do you think when you see where that US numbers are right now. And you see what Canada's experiencing a few weeks after they are Thanksgiving. This is. Very concerning Diana and you know how we die and after holidays in the house where there was Memorial Day fourth of July Labor Day we've had surgeons after all these holidays given more baseline is street around 200000. Cases a day with escalating hospitalizations. There's no question that there's going to be more searches after Thanksgiving. And a lot of people are trying to get tested her clothing before the holiday now Quest Diagnostics is saying. Expect longer wait times to get resolved so what does that mean from a public health standpoint. Right I mean we're seeing long lines you know. Testing is an important part of our public health measures because we want to find out who's positive so then we can isolate them traced their contacts the longer changed again these test results action the less you noted that the more challenging the public health measures are and armed she just will lead to more spread of the virus. So if you do get your results back in your negative. What precautions do you have to take it you're getting together with. Other households. Important question OPEC so single negative tests. Are only so important and what I mean by this is. There was an animal study basically shtick came out and sent undated a construction and 100%. Of people test negative after an additional three days so day forecast typically one day before the onset of symptoms 6012%. Of patients had false negatives. Ryan understood and let's get to the good news AstraZeneca is reporting that it's coded vaccine is in their words. Highly effective base say 70% overall in the group that received half the dose followed by a bull dosed boost. One month after had 90%. Effectiveness so. What does that effectiveness rate mean what do you think when you see this news it especially in light of what we've heard from Pfizer in midair and a. That's important so we think we got his information three weeks ago we'd be just bursting at the seams computer war she flu affected as the flu vaccine which is where happier if it's 50%. So we're trying to figure out why a overall with 70% is actually the one thing I want you to remember the AstraZeneca clinical trial didn't have a pause so one question is how. How many patients only got a single dose of the vaccine huge and actually got Hogan nineteen before they got that second dose not shortcuts part of does statistics we're hearing on the and I want you don't you mentioned it to. The defects and it was the first dose when it was hatched jokes and the second dose was full those that. Up to 90% effective and is now that's also potentially why would have to those first keep you the highest result as opposed to a full dose for the first and second vaccines again these things he needs to be explained I just want to caution the public should we have to be careful when we're comparing a cross trials we have to really wait for these final result. I want to be encouraging though winter's vaccine is going likely going to be less expensive and it only requires refrigeration. And the AstraZeneca Oxford group is using a viral vector to deliver. Deep two in order to deliberate the genes that are gonna make despite protein why that's good news is when you're using viral vector is remember viruses can replicate. And you can you can really scale up so there should be a lot of this vaccine for the world but it remains to be seen. We you know as we get final results from this company alright actor and thank you it always.
This transcript has been automatically generated and may not be 100% accurate.