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Why you can't compare Covid-19 vaccines
In the US, the first two available Covid-19 vaccines were the ones from Pfizer/BioNTech and Moderna. Both vaccines have very high "efficacy rates," of around 95%. But the third vaccine introduced in the US, from Johnson & Johnson, has a considerably lower efficacy rate: just 66%.
Look at those numbers next to each other, and it's natural to conclude that one of them is considerably worse. Why settle for 66% when you can have 95%? But that isn't the right way to understand a vaccine's efficacy rate, or even to understand what a vaccine does. And public health experts say that if you really want to know which vaccine is the best one, efficacy isn't actually the most important number at all.
Researchers working on Covid-19 vaccines have smashed speed records, bringing new vaccines from development to distribution in less than a year. They did this with the help of billions of dollars of unprecedented global investment -- but also, in some cases, with a new type of vaccine technology.
There are four traditional types of vaccines, and they all require the growing and handling of live pathogens in a lab, a time-consuming process than can add months or years to development. But two new types of vaccines skip that step altogether by moving that work from the lab to our bodies. mRNA vaccines, like the ones from Pfizer-BioNTech and Moderna; and Adenovirus vaccines, like those from Johnson & Johnson and AstraZeneca; do this by sending genetic instructions directly into our cells, which then produce the harmless protein the body needs to learn to fight Covid-19. Because these proteins are produced from within cells rather than injected from the outside, they may be less likely to provoke adverse reactions in the recipient.
The result has been a host of vaccines developed faster than ever. But it's also ushered us into a new age of vaccine technology, one in which we can send our own bodies the instructions on how to protect themselves. That technology is already being used to drive research on vaccines for HIV and cancer. These new types of vaccines are weapons we developed to fight the coronavirus - but their real impact is just beginning.
Note: The headline on this video has been changed.
Previous title: How the newest vaccines fight Covid-19
Further reading:
Our original article on Vox.com by Umair Irfan: https://www.vox.com/2020/8/13/2135902...
A breakdown of the types of vaccines: https://www.vaccines.gov/basics/types
Infographic on the differences between mRNA vaccines and traditional vaccines: https://www.breakthroughs.com/advanci...
The New York Times has a really wonderful in-depth breakdown of how each of the vaccines work: https://www.nytimes.com/interactive/2...
