The two experts featured on Morning Joe today seem pretty happy with the news about pending approval on the Johnson & Johnson vaccine.

"The good news for this week, Mika, is the Johnson & Johnson vaccine," Dr. David Campbell, MSNBC's health correspondent, said.

"This is the single dose vaccine that has gone through the beginning phases of the FDA advisory committee. And tomorrow this advisory committee will meet to discuss whether the FDA will grant or begin considering granting an emergency use authorization. And if they do, by next week, the prediction is three or four million doses will be made available to the United States for the J&J single dose vaccine. And this is coming out of a big multinational study that included South Africa and Brazil. So these variants that everybody is worried about do have some effect from this J&J vaccine, Mika. It's good news."

"Dr. McMurray-Heath, we got the information about J&J clearing the hurdle, hopefully in the next few days gets emergency use authorization from the FDA, what does it mean for the big picture and the speed in which we might get the entire country vaccinated? And as we look at some of these variants not just from South Africa, but they're talking about a new one in New York City that's spreading around, will those vaccines protect against those variants?"

"Well, it's a huge milestone to now have three vaccines within sight of the finish line of getting emergency use authorization from the Food and Drug administration," McMurray-Heath said.

"So Friday will be a huge day in the history of us combatting this covid pandemic. It's going to be wonderful to see the J&J vaccine get distributed. It offers hope that we'll more easily be able to vaccinate rural communities, where it's been difficult to keep the first two vaccines at the super cold temperatures that have been required. J&J is much more stable at regular refrigeration. And because it requires only one dose, it will give us more flexibility.

"So we've always said it's great to have multiple feathers in your quiver, so that we're prepared for this. But the variants are a real concern, and there's good news on that front as well. Just this week, we learned that Moderna is starting to send new versions of its vaccine to the NIH for clinical testing that is specifically designed to combat the variant.

"So this may be like the flu vaccine. You get your Pfizer, Moderna, J&J vaccine right now. And then perhaps as variants emerge and we learn more about them, you get a booster so you that you're even more protected against them. But to date, all of the data is showing that the existing three vaccines have very solid efficacy, even against the variants that have been detected. So this is good news."