A first generation vaccine, unless it turns out to be both highly effective and widely taken, won’t end the pandemic on its own. I wrote back in early summer that a first generation vaccine, on its own, probably wouldn’t get us out of the pandemic but combined with other measures would make life – and travel – more normal than it used to be. We now have a new study, with new math, backing up this view.
There are several vaccines in phase 3 trials. For the U.S. the most promising are BioNTech-Pfizer, moderna, AstraZeneca-Oxford, Johnson & Johnson and Novavax. The U.K. vaccine and the Johnson & Johnson vaccine both had to pause and restart trials while adverse health issues among trial participants were investigated. There’s also several Chinese vaccines, and China is using access to these for geopolitical advantage. With poor U.S.-Sino relations we’re unlikely to have access to them even if they prove safe and effective. (Here I leave out the Russian and Australian candidates for now.)
I’ve worried somewhat about the moderna candidate, because of the significant unloading of the company’s stock by its executives and the early promotion of results without data in advance of share sales. It’s a new technology (mRNA) that’s similar to what’s being used by the German BioNTech in cooperation with Pfizer. Both of those vaccines have to be stored at below zero temperatures and require two doses.
Let’s look at the timeline for a moment.
- Assume a December emergency use approval for a very limited population, whether health care workers or nursing home residents. It will take a few weeks for initial roll out.
- And two doses, taken 3-4 weeks apart. Plus two weeks to experience full protective immunity afte the second dose.
We’re looking at probably early March before the first people have immunity from a vaccine. And several months after that before protective immunity is conferred on a wide array of the population. But summer 2021 is likely to look a lot better than the U.S. looks today, and we may have both a weather benefit (outside of the hottest parts of the country where people stay inside) and the benefit of treatments that make getting the virus less scary as well as much of the population having had the virus recently enough that they retain some immunity.
Great, that means we can all stop wearing masks by next summer and jump on planes to go anywhere we want, right? Not so fast.
- We don’t know yet how effective these first generation vaccines will be. The FDA has said approval will require both a showing of safety (they’ll likely be too conservative, safety needs to be weighed against the vaccine benefit with nearly 1000 deaths per day some of which could be avoided) but also of greater than 50% efficacy.
- If the first vaccine attempts only get us 50% efficacy, and 50% of people stopped wearing masks, you’d need over half the population to have taken the vaccine to suppress the virus.
[I]f face mask usage stops completely, a weak vaccine would not suppress the epidemic, and further major outbreaks would occur. A moderate vaccine with coverage of 48-78% or a strong vaccine (100% effective) with coverage of 33-58% would be required to suppress the epidemic.
How effective these first vaccines turn out to be, combined with how many people take them, will drive when mask mandates go away. A ‘vaccine only’ isn’t going to do it. We’re going to be stuck wearing masks on planes for some time.
And if Joe Biden becomes President we may see a national transportation mask mandate. Reversing a federal rule is likely to be far less flexible than leaving things up to the airlines, which means mask requirements are likely to stay in place far longer than needed. We still take off our shoes and have to toss bottled water as we go through security checkpoints after all.
Bear in mind this timeline and removal of mask mandates is all specific to the United States, which is likely to get vaccines faster than some other parts of the world. So when a U.S. gets a vaccine is not indicative of when mandates go away elsewhere, or even when other countries open up their borders. For some time we may expect to have more paperwork required for international travel, some combination of ongoing testing and proof of vaccination.