Gamechanger? Real-world data from Israel shows Pfizer vaccine cuts asymptomatic infection by 94%

It feels silly to call this a “gamechanger” when (a) the available evidence already pointed to a much lower risk of asymptomatic COVID for the vaccinated and (b) vaccinated people are going to do what they want to do regardless of what a study says.


Recall that this Gallup poll shows that those who have had both shots are still behaving almost as cautiously as people who haven’t, evidence that the warnings from experts like Fauci and Rochelle Walensky about vaccinated people socializing too freely are having some effect. Expert opinion is influencing public behavior broadly, if not in every individual case. Which means that, if we want people who’ve been immunized to feel comfortable going out again, a little expert encouragement might go a long way.

This new data makes that encouragement more likely. The thing Fauci, Walensky, and other scientists are most worried about with vaccinated people is their capacity to infect others at a moment when most of the population remains unimmunized. That’s why they’re urging the vaccinated to avoid public spaces like restaurants and movie theaters for now. Just because you’re protected from COVID doesn’t mean you can’t transmit the virus to someone else — and if you don’t have any symptoms to clue you into the fact that you’re infected, you’ll have no reason to avoid those public spaces. Asymptomatic infection has been the most diabolical feature of the coronavirus since the start of the pandemic and risk-averse doctors aren’t about to overlook the threat from it now in vaccinated people. At least, not until a study gives them good reason to believe that the vaccines sharply reduce the odds of asymptomatic infection, not just symptomatic disease.

We now have that study:

Pfizer Inc and BioNTech SE said Wednesday that real-world data from Israel suggests that their Covid-19 vaccine is 94 percent effective in preventing asymptomatic infections, meaning the vaccine could significantly reduce transmission.

The companies also said the latest analysis of the Israeli data shows the vaccine was 97 percent effective in preventing symptomatic disease, severe disease and death. That is basically in line with the 95 percent efficacy Pfizer and BioNTech reported from the vaccine’s late-stage clinical trial in December.

The analysis also shows real-world evidence of the vaccine’s effectiveness against a highly infectious variant of Covid-19 first discovered in Britain, known as B.1.1.7. More than 80 percent of the tested specimens when the analysis was conducted were variant B.1.1.7.

Ninety-four percent effective in preventing infections even in a population that’s been overrun by the more contagious British variant of the virus. Not only are vaccinated people rarely getting sick, they’re rarely getting infected, which means only very rarely are they transmitting the virus to others. Assume further that they’re wearing masks in public and practicing some basic distancing and their odds of infecting others must be downright minuscule.

Which raises a question: Why isn’t the CDC encouraging them to start socializing in public spaces? Instead of asking them to avoid restaurants and theaters to protect the unvaccinated, the agency could impress upon them the need for simple precautions (masks) to further reduce risk of transmission while visiting them. As for travel, considering how low the baseline risk of infection is on planes, the risk of being infected by a masked-up vaccinated person is likely to be close to zero. Today’s data should — and maybe will — give the feds the confidence to finally greenlight greater risk-taking by the immunized.

Let’s hope so, at least. It’s still early in 2021 but we may not see a more dystopian headline this year than this one:

We’re almost three months into the national vaccination program, a program in which nursing-home residents were given early priority, and only now is CMS formally recommending that vaccinated seniors feel free to embrace family members. (“There is no substitute for physical contact, such as the warm embrace between a resident and their loved one.”) This Onion piece that circulated yesterday is supposed to be satirical, but is it really?

Fingers crossed, but I think the CDC is about to wise up on restrictions for the vaccinated. It’s not just nobodies like me who are grumbling about them being overcautious, it’s people like Scott Gottlieb and Leana Wen. Several times this week, federal officials like Fauci have hinted to the media that the guidance for immunized people is going to loosen up, and sooner than you think. They know the public is impatient about this and they worry that being hyper-cautious about socializing will discourage fencesitters from getting their shots, so they’re prepared to relax the rules. Hopefully the new Pfizer data pushes them even closer. Here’s Fauci again assuring critics that the new, more liberal guidelines are coming “really quite imminently.”