Question: I keep seeing that it will apparently take us 12–18 months to develop a vaccine. Where does that projection come from, and is it realistic?
Answer: As of 11 May, there are 110 vaccination candidates under evaluation around the world, 8 of which are in clinical development (Table 1). The world is moving at “pandemic speed” to find a vaccine/s that is both safe and effective. As you may recall, the 12–18 month timeline came into our collective consciousness on March 2nd, when Dr. Fauci told the President during a televised coronavirus meeting that a vaccine would be deployable “… at the earliest, a year to a year and a half, no matter how fast you go.” Many public health experts believe that the 12–18 month estimate is “ridiculously optimistic,” as Dr. Paul Offit, the co-inventor of the successful rotavirus vaccine recently put it. Nevertheless, according to an article published by Science yesterday, “…the organizers of a U.S. government push called Operation Warp Speed have little use for conventional wisdom. The project, vaguely described to date but likely to be formally announced by the White House in the coming days, will pick a diverse set of vaccine candidates and pour essentially limitless resources into unprecedented comparative studies in animals, fast-tracked human trials, and manufacturing. Eschewing international cooperation — and any vaccine candidates from China — it hopes to have 300 million doses by January 2021 of a proven product, reserved for Americans.”
So, where do these timeline estimates stem from? Let’s examine the vaccine development cycle. According to CDC, there are 6 steps in the cycle:
- Exploratory stage: identify candidate antigens
- Pre-clinical stage: use tissue/cell culture and animal studies
- Clinical development: generally a 3 phase process with each phase introducing the vaccine to a bigger and wider pool of individuals (Phase 3== thousands)
- Regulatory review and approval: FDA reviews and if it passes muster, approves
- Manufacturing: Usually the realm of major drug manufacturers in the private sector
- Quality control: ongoing monitoring and reporting of adverse events
Generally, it takes years for a vaccination to make it through these cycles and into widespread use. And the overwhelming majority of vaccine candidates fail. Two weeks ago, the New York Times had a fascinating description — with great visualizations — of how the process works, how long the process takes, and what it would mean to actually have a vaccine in that “warp speed” timeframe. For a more in-depth answer to your question, please read it! In the meantime, Figure 1 is a screenshot of one of its visualizations, which shows in blue bars the COVID-19 vaccination goal and in grey, the typical vaccination timeline. As you can see, the timeline we’re aiming for is ridiculously optimistic, but that doesn’t mean it’s impossible. Scientists around the world are racing, funding is pouring in, and demand is urgent.
Table 1. Candidate Vaccines under Clinical Investigation (WHO)
Figure 1. Goal vs. Typical Timeline for COVID-19 Vaccination Development (NY Times)
