COVID variants and vaccine boosters

Do you need a booster? How worried should you be?

I’ve been getting huge numbers of questions from patients, friends, and family on COVID variants, vaccine breakthrough, and whether or not vaccinated folks are going to need booster shots.

On top of that, I’ve started to see some patients in the hospital getting COVID despite being vaccinated.

Now we have Pfizer making announcements about seeking FDA approval for boosters, the New York Times suggesting that we’re going to need boosters, and the co-founder of Moderna claiming boosters will almost certainly be needed.

And so it’s understandable that many of us are quite anxious about what the phase of the pandemic is going to be like.

So let’s take a look at some of these topics.

The vaccines remain incredibly effective

Let’s start with the most important thing: these vaccines are really amazing scientific achievements.

If you look at the published data on the Moderna, Pfizer, or Johnson & Johnson vaccines, you know that they work really well to prevent symptomatic COVID, severe COVID, and death from COVID.

They don’t just work in clinical trials - they work in the real world too. These incredible vaccines are a large part of why we’ve had such a precipitous drop in COVID hospitalizations and deaths over the last few months.

Unfortunately, like any medical treatment, these vaccines aren’t perfect.

It is still possible to get COVID after you’ve been vaccinated.

It is still possible to die from COVID after you’ve been vaccinated.

And although it does seem that the Delta variant - a slightly different strain of the SARS-CoV-2 virus first identified in India - evades vaccines better than the strains that we’ve been dealing with so far, the vaccines are still protective against it.

The Delta strain seems really bad… how bad it is?

With any new strain, you worry about 3 major things:

  1. Virulence or pathogenicity - is a new variant more likely to make you really sick or kill you?

  2. Transmissibility - how easily is the virus spread from one person to another?

  3. Response to acquired immunity from prior infection and vaccines - does previous COVID infection protected against the new strain? And will our vaccines work against this new B117 variant?

When it comes to the new strain, it doesn’t seem that COVID is more severe. But the virus is quite a bit more contagious.

I’ve written before about how a more contagious virus is worse than a virus that causes more severe infection.

The reason for that is the same reason that a respiratory virus can cause a globe-altering pandemic - exponential spread infects more people quickly which leads to more illness, suffering, death, and most importantly, more possibility for mutation.

I think that the Delta variant is quite concerning given our current worldwide state of herd immunity and vaccination efforts.

So should I get a booster?

The booster talk is so premature that I can’t believe it’s getting so much attention.

I’ve written time and time again that the measure for effectiveness of any intervention needs to be on an outcome that matters clinically.

Who cares what your antibody titers are if you get really sick from COVID?

And conversely, who cares whether your antibody titers are zero if you don’t get sick?

That’s why I think the stories about reduced vaccine effectiveness with the Delta variant or journal articles detailing antibody responses post vaccination are kind of missing the point.

It’s not that this research is unimportant, but immunity is more complex than just an antibody response.

The burden of proof needs to be on proving that a booster reduces severe disease, hospitalization, and death from COVID.

The preliminary research on antibody levels doesn’t come close to the necessary level of evidence to be a persuasive argument for a booster. You should wait on a clinical trial demonstrating an improvement in important outcomes before getting a booster.

Boosters in the US are much less important than vaccinating the world

Although the local infectivity rates play the biggest role when it comes to your personal COVID risk in the short term, the long term trajectory of this pandemic is going to be dictated by global spread and immunity.

Vaccine production and distribution has not yet ramped up to the level that it needs to be in order to immunize the world.

Before someone in the United States gets a third vaccine dose, we should be vaccinating the world. You’ll be safer in the long term if someone in Nigeria, or Bangladesh, or Colombia gets vaccinated than if you get your third Moderna shot.

The more the virus spread, the more likely it is to develop additional vaccine-evading mutations.

Getting more first doses out there is orders of magnitude more important than getting a handful of third doses.

The way we’re talking about vaccines is slowing our vaccination efforts

We’re having enough trouble vaccinating people here that a lot of our discourse is counterproductive.

I think it’s insane to be discussing vaccinating 12-15 year olds - or even younger kids - rather than focusing on high risk adults and sending vaccine doses abroad.

And how much is the discussion about boosters turning a person who is vaccine-hesitant into someone who is vaccine-averse?

The fact is that vaccination greatly slows spread of the virus and that vaccination reduces the severity of disease even if you happen to get sick after being vaccinated.

The gloom-and-doom nature of the discourse is discouraging. This was true on masks and it’s true on vaccines. Partly because our news ecosystem is dominated by things that make us scared and outraged, the stories that our counterproductive for public health tend to become the most widespread.

Here’s the bottom line

The vaccines work really well. Even against the Delta variant.

The Delta variant is concerning for the pandemic trajectory because it spreads more easily even though it doesn’t cause more severe disease.

The talk of boosters is extremely premature - show me a clinical trial demonstrating important outcomes, not just antibody levels.

Vaccinating the world is more important than vaccinating kids here or giving anyone a booster.

Discussing vaccination through the lens of mandatory boosters is likely to further discourage vaccine acceptance in America.


Share Gregory Katz's email newsletter

Thank you for reading! Please share on social media and encourage your friends and family to subscribe!