March 12, 2021

Any of the vaccines will do

If you get the opportunity to take any one of the approved COVID-19 vaccines, jump on it, writes NCSE Executive Director Ann Reid.

A sedan and a sports car side by side

How quickly we forget. When the coronavirus pandemic started, public health experts warned that vaccines were unlikely to become available for years. Having vaccines within 18 months was considered a wildly optimistic estimate. (Those experts were not just being killjoys—ensuring that a vaccine is safe and effective takes time, and historically the process had never been completed in less than 18 months.) Now here it is just a year since the World Health Organization declared the coronavirus outbreak to be a pandemic, and we have not just one but three vaccines in the U.S. alone, with several more approved and in use in the rest of the world.

So now we have these three amazing vaccines … and people are worried about whether they can get the “best” one. Let’s discuss.

It might be worth talking to your students, first off, about why this particular vaccine development process went so quickly, especially since the unprecedented speed makes some people nervous about getting vaccinated. This article from Nature does a good job explaining what accelerated the process—the short answer is 1) pre-existing research: lots of relevant science research had already been done; 2) money, money, money: pharmaceutical companies were guaranteed to be reimbursed for the costs of developing and testing vaccines whether or not they worked; and 3) luck: the coronavirus mutates relatively slowly, the new vaccine approaches worked, and the vaccines had no serious side effects.

But that’s not what I want to focus on. Instead, I want to talk about why the difference in effectiveness among the three vaccines currently available in the U.S. doesn’t matter as much as you might think, which is why public health experts are telling people to accept whichever one they are offered even though two of them are, objectively, “better” than the third.

Here’s what I’m going to compare this situation to. Let’s say you’re in that scene from Raiders of the Lost Ark: the big boulder is rolling down the tunnel behind you and you think you are doomed. But ahead of you, you see a sports car with its engine running. You jump in the sports car and slam on the accelerator. You outrun the boulder! You are saved! Hurrah! Now, same scenario. The boulder is bearing down on you. Ahead of you is a really nice sedan with its engine running. You jump in the sedan and slam on the accelerator. The sedan isn’t quite as fast. The boulder might tap the bumper and leave a slight scrape. But you still outrun the boulder! You are saved! Hurrah!

You see, all you really care about is outrunning the boulder. If the sports car can accelerate to 60 miles per hour in 2.5 seconds and the sedan takes 7.5 seconds, it doesn’t matter—both cars save your life.

The more people we vaccinate, the harder it will be for the virus to spread and the fewer opportunities it will have to mutate in ways that allow it to spread faster, infect more people, or evade pre-existing or vaccine-induced immunity.

Okay, fine. But still, a vaccine that is 95% effective seems like it would be much better than one that is 70% effective! Well, it is betterl Remember what those efficacy percentages mean. When the vaccines were compared to placebos in tens of thousands of volunteers, researchers measured how many participants developed COVID-19. Then they looked at how many of those cases occurred in those who had received the vaccine versus those who received the placebo. If only 5% of the cases occurred in the vaccinated group, the vaccine was deemed to be 95% effective. That’s how effective the mRNA vaccines made by Moderna and Pfizer proved to be. The Johnson & Johnson vaccine was ~70% effective. Remember, that does not mean that you have a 30% chance of catching COVID if you get the J&J vaccine versus a 5% chance with the others—it means that your risk of contracting the disease is reduced by 95% in one case and 70% in the other. Reducing your risk by 70% is pretty darn good, and it’s even better when you consider that the all three vaccines are all just about 100% effective at preventing a case of COVID that will put you in the hospital or kill you.

In other words, if you get any of these vaccines, the boulder will not run over you.

There are a few reasons to think that the difference in effectiveness of the vaccines may not even be as large as the raw trial results suggest, the main one being that the Johnson & Johnson trials were done when there was much higher circulation of new variants of the virus, against which the vaccines may all be slightly less effective. Time will tell. But if new variants might reduce the effectiveness of all the vaccines, then there’s even more reason for everyone to get whichever vaccine they can, as quickly as they can. Since the J&J vaccine only requires one dose and doesn’t have to be stored at ultra-low temperatures, it should be easier to distribute and administer in remote locations and to people who might have a hard time reaching a vaccination site twice. The easier it is to reach even hard-to-reach places and people, the slower the virus will spread.

Because that’s the bottom line: the more people we vaccinate, the harder it will be for the virus to spread and the fewer opportunities it will have to mutate in ways that allow it to spread faster, infect more people, or evade pre-existing or vaccine-induced immunity. Ultimately, fewer people will be crushed by the boulder that has already killed more than 540,000 Americans. Just jump in a car, any car, and gun it.

NCSE Executive Director Ann Reid

Ann Reid is a former Executive Director of NCSE.

reid@ncse.ngo