A paper published by the International Journal of Vaccine Theory, Practice and Research identifies some of the incredible, and sobering, firsts for the COVID-19 vaccines.
Many aspects of Covid-19 and subsequent vaccine development are unprecedented for a vaccine deployed for use in the general population. Some of these includes the following.
- 1.First to use PEG (polyethylene glycol) in an injection (see text)
- 2.First to use mRNA vaccine technology against an infectious agent
- 3.First time Moderna has brought any product to market
- 4.First to have public health officials telling those receiving the vaccination to expect an adverse reaction
- 5.First to be implemented publicly with nothing more than preliminary efficacy data (see text)
- 6.First vaccine to make no clear claims about reducing infections, transmissibility, or deaths
- 7.First coronavirus vaccine ever attempted in humans
- 8.First injection of genetically modified polynucleotides in the general population
This is quite striking given that most “unprecedented” vaccines have a 2% probability for success.
Development of mRNA vaccines against infectious disease is unprecedented in many ways. In a 2018 publication sponsored by the Bill and Melinda Gates Foundation, vaccines were divided into three categories: Simple, Complex, and Unprecedented (Young et al., 2018). Simple and Complex vaccines represented standard and modified applications of existing vaccine technologies. Unprecedented represents a category of Unprecedented vaccine against a disease for which there has never before been a suitable vaccine. Vaccines against HIV and malaria are examples. As their analysis indicates, depicted in Figure 1, unprecedented vaccines are expected to take 12.5 years to develop. Even more ominously, they have a 5% estimated chance of making it through Phase II trials (assessing efficacy) and, of that 5%, a 40% chance of making it through Phase III trials (assessing population benefit). In other words, an unprecedented vaccine was predicted to have a 2% probability of success at the stage of a Phase III clinical trial. As the authors bluntly put it, there is a “low probability of success, especially for unprecedented vaccines.”
