The Whole View, Episode 441: COVID-19 Vaccines Part 2 - Pfizer/BioNTech vs Moderna 
Welcome back to episode 441 of the Whole View. (0:27)    
Stacy reminds everyone that this is part 2 of the Covid show on vaccines.
So if you've done listened to part 1, be sure to do so first, so this episode will make more sense.
She also reminds listeners that this show isn't about opinions. We all have our own, and Stacy and Sarah aren't here to debate that.
As always, they are here to break down the science for you to make your own informed choices.
Stacy takes a moment to thank Sarah for doing all the research to make these shows possible.
She and Sarah received a lot of feedback from listeners who enjoyed a straightforward approach to this topic.
Sarah explains that it's always more challenging when she knows they're getting into a topic where there's a lot more disinformation and misinformation to combat.
Especially when they take a more myth-busting approach because that information could have come to you from a trusted source.
Sarah extends her gratitude to listeners for being so open to the science and having an open mind.
Sarah takes a minute to run through a recap of mRNA vaccines and how they work, which she covered extensively in Episode 440.
She also reiterates how important funding for basic science discovery is because we almost didn't get this mRNA research.
Different Variants of Concern
Sarah reminds listeners that the variations we see in the virus are different enough to count as a new strain. (15:50)
They're called "variants of concern" because they have a few mutations that change the virology (basically make a function change).
We know the novel coronavirus mutates very slowly. But because of the sheer number of people, it's infected so far this year, it's had many opportunities to mutate.
The UK and South African variants have a mutation in common, which is how easily the spike protein binds to the ACE2 receptions and speeding up the replication rate.
This means the infection dose we need to be exposed to become infected is slower. It also means an infected person is shedding more virus than other strains.
In fact, the UK strain is showing 40%-80% more contagious than the original virus.
Pfizer/BioNTech and Moderna both have looked into how the antibodies bind to the different strains, including the UK and South African variants.
Why Target The Spike Protein?
Antibodies we make after vaccination bind with the spike protein to block ACE2 binding.
Pfizer/BioNTech has shown that the antibodies that study participants made in response to vaccination effectively bind to and neutralize the UK strain.
Moderna has shown its vaccine is equally good at neutralizing the UK strain.
The vaccines may not work as well against the South African strain but will still provide some protection.
Early data using convalescent plasma shows antibodies against other covid-19 strains don't effectively neutralize the South African strain.
That's bad news for monoclonal antibody treatments, convalescent plasma treatments, and natural infection.
While the Company expects these levels of neutralizing antibodies to be protective, pseudovirus neutralizing antibody titers were approximately 6-fold lower than prior variants.
These lower titers may suggest a potential risk of the earlier waning of immunity to the new B.1.351 strains.
Moderna is working on additional boosters to help bind the South African variant. For more information, check out their latest new release.
Good news, though- a second vaccine against this strain would be easy to make!
Both UK and South African variants have N501Y mutation, which confers a replicative advantage, so when you start shedding the virus, you shed more of it.
This is how scientists currently believe it's more contagious.
The South African variant also attaches to ACE2 receptors more strongly because of two other mutations, E484K and K417N.
Almost all vaccines require "boosters," which is why the Covid vaccine req