There was some good (if very preliminary) news from Moderna on their vaccine candidate:
And yes it does seem to be good news. But leaving aside that they so far only report results for 8 people from their 45 person Phase 1 trial, some 4th grade arithmetic shows that even if (as we all hope) they give us a usable vaccine, it’s not going to be a total game changer – and certainly not in 2021.
Why? First off, from reading the press release it is pretty clear that a minimum of two doses will be needed to get the kind of immune response we need. Optimistically, they are talking of ramping up to 1 billion doses a year:
https://www.biopharmadive.com/news/coronavirus-moderna-lonza-mrna-vaccine-manufacturing/577169/
That will cover 1/2 a billion people at most. Again using some fourth grade arithmetic, that’s enough to treat about 7% of the population of the world, roughly enough to treat the people living in the United States, Canada and Mexico. Or, more hopefully, health care workers, first responders and essential workers world wide. If we end up with vaccine nationalism, does that gives us Smoots-Hawley effects on the world’s economy (https://en.wikipedia.org/wiki/Smoot%E2%80%93Hawley_Tariff_Act)?
And remember, to be able to go back to life something like it once was, we need to vaccinate enough people to get herd immunity. For that we would need about 10 billion doses worldwide (500 million doses more or less for the United States alone). So please keep in mind this quote from the CEO of Moderna:
“The odds that every program works are really low, obviously, but I really hope we have three, four, five vaccines, because no manufacturer can make enough doses for the planet,”
So, to reiterate, yes potentially very good news but please people temper your enthusiasm. Keep in mind not only will there be the difficulty of producing enough doses, you can’t ever forget that most vaccines candidates don’t get through phase 3 trials even if they have a successful phase 1. Even if we assume the Moderna results are similar to what a Phase 2 might give (they aren’t, although they have some elements of a Phase 2), then for a random vaccine in development, the historical odds are roughly ⅕ that they can go from Phase 2 to Phase 3 and even lower that they can go on from Phase 3 to a successful vaccine.
“The foremost challenge in vaccine development is reducing the average transition rate from clinical phase II to III. Between these value chain phases the risk profile incorporating all data has an estimated transition probability of 0,21. It represents the highest attrition rate when compared to the productivity of the other phases.” (Taken from: