Relax, America: The Vaccines Are Still Working

They’re not perfect and they never were. But they remain the only way to end the pandemic.  

A woman wearing a blue mask and gloves pulls vaccine into a syringe.
Kirsty O'Connor / PA / Getty

About the author: Craig Spencer is an emergency medicine physician and director of global health in emergency medicine at New York Presbyterian/Columbia University Medical Center.

As Delta surges across the country, many fully vaccinated Americans are wondering how much their shots still protect them.

There’s reason to be confused. Pfizer says its vaccine becomes less effective with time. Moderna says its doesn’t. And Johnson & Johnson says its vaccine holds up against the Delta variant, but not everyone agrees.

For anyone perplexed by what this all means for your own safety, the main takeaway hasn’t changed: The vaccines are still miraculous. And they’re still doing exactly what we need them to do.

This wasn’t the message many took away from last week’s CDC announcement, however. After an investigation into an outbreak in Provincetown, Massachusetts, where vaccinated people made up 74 percent of the 469 cases, the CDC warned that fully vaccinated people infected with the coronavirus harbor as much virus as unvaccinated people.

As a result, the agency recommended that fully vaccinated people resume mask wearing in many instances. This was sad and shocking news to everyone who had been told just two months earlier that they could safely toss their masks aside once fully immunized. Overnight, hot vax summer started feeling more like hot mask summer.

Adding to the onslaught of bad news was an internal CDC slide deck leaked a few days later in which the agency warned that “the war has changed” and classified the Delta variant as more transmissible than smallpox, the common cold, and Ebola. Major news outlets published misleading headlines suggesting that breakthrough infections were extremely common and that vaccinated people are as likely to spread COVID-19 as the unvaccinated. The White House immediately pushed back on media coverage it considered “hyperbolic and frankly irresponsible,” but the damage was done: COVID-19 vaccines were facing a credibility crisis.

This is an opportune time to get one thing straight: The vaccines are still incredible, but they aren’t perfect. And they never have been.

It’s worth remembering that this time last year, experts weren’t certain any of the vaccine candidates would pan out. And for any that did, they didn’t expect an efficacy of more than 70 percent.

Yet the mRNA vaccines (Pfizer and Moderna) that most Americans have received showed stunning efficacy of more than 90 percent in clinical trials. Still, none were 100 percent effective, even if many people who got their shots started treating them as impenetrable armor.

That’s why we expected breakthrough infections, even before the Delta variant arrived.

It’s a question of simple arithmetic: As more people get vaccinated, we expect more breakthrough infections in vaccinated people. Imagine a world where 100 percent of people were immunized. In that scenario, 100 percent of infections would be in vaccinated individuals, even if their likelihood of being infected in the first place had been dramatically lowered by getting the shots.

Many people already know someone who’s tested positive for COVID-19 after being fully vaccinated. If you don’t, you likely soon will. If only 1 percent of the 165 million fully vaccinated Americans have a breakthrough infection, that’s still 1.6 million people.

In Israel, data show that vaccine efficacy may have dropped to 64 percent, down from 95 percent in clinical trials. But other data from England, India, and Canada show that efficacy against Delta is still greater than 87 percent. Even if the exact efficacy isn’t certain, one thing is: You can still get infected with coronavirus after you’re fully vaccinated. But the likelihood is low. And compared with infections in the unvaccinated, these breakthrough infections are more likely to be asymptomatic. For the people who do experience symptoms, they’ll likely have fewer of them than the unvaccinated.

Moreover—and this was a source of widespread confusion in the wake of the Provincetown outbreak—even if vaccinated people with breakthrough infections harbor as much virus as infected unvaccinated people, vaccinated people still collectively lower spread, given that they’re much less likely to get infected in the first place.

Yes, Delta has shaved a few points off the vaccines’ ability to prevent symptomatic illness. But it hasn’t blunted our vaccines’ crucial role in combatting the pandemic.

That’s because the vaccines have performed beyond our most optimistic projections at the thing that matters most: keeping people alive.

I’ve been working on the front lines as an emergency-medicine physician since the start of the pandemic. My colleagues and I would feel helpless when patients came in unable to breathe and rapidly deteriorating. Some days I saw more people die in New York of COVID-19 than I did in Guinea while treating Ebola. But once vaccination started, in December 2020, we began to see a dramatic change.

With a vaccination campaign targeted at the most vulnerable, the impact was almost immediate. In nursing homes—which had previously accounted for 40 percent of all COVID-19-related fatalities—deaths plummeted. And according to a Commonwealth Fund study released last month, the vaccine rollout has saved nearly 300,000 lives. The vaccines dramatically changed the course of this pandemic here in the U.S.

Even with Delta, the likelihood of severe illness if you’re fully immunized is still a small fraction of the likelihood for the unvaccinated. Almost all COVID-19 hospitalizations and deaths have occurred in the unvaccinated or partially vaccinated. In other words, nearly every COVID-19-related death right now is preventable with vaccination.

So what can we take away from all the recent news, and what does this mean for you?

For one thing, the Provincetown outbreak didn't prove that the vaccines were imperfect—we already knew that. But it did prove how well they work against the things that matter most. Of the 374 fully vaccinated people who experienced a breakthrough infection in Provincetown, only four were hospitalized. None died.

For another, we should recognize that the battle isn’t over. The Delta variant is sweeping across the country, spoiling what was supposed to be a joyous summer. That’s why, for the unvaccinated, right now may be the most dangerous time of the pandemic.

For the fully immunized, masks will become part of our daily lives again, especially for those of us living with vulnerable family members. And boosters may also be in our future, particularly for the immunocompromised or elderly. More practically, it means that you should get tested for COVID-19 if you have symptoms.

Delta is indeed the most formidable foe we’ve faced. But even if Delta has dented our armor, we remain remarkably protected against the worst outcomes COVID-19 has to offer.

The war has changed. The tools we need to win it haven’t.