Hi, Sheri,

Big week on the Covid news front!

Vaccines: A light at the end of the tunnel? As I’m sure you’ve heard, Pfizer and Moderna both announced preliminary results indicating that their vaccines are about 95 percent effective. This far exceeds even the most optimistic estimates and is fantastic news. That said, there are several caveats:

  • The data haven’t been published yet, so independent parties haven’t been able to evaluate the claims.
  • People with chronic diseases and pre-existing conditions were excluded from the trials, so we don’t know how the vaccines work in these populations.
  • We have limited data on how well they work in the elderly, and no data on how well they work in children.
  • We don’t know how long the immunity from the vaccines will last (though recent research on immunity from natural infection suggests the news may be good here).
  • The Pfizer vaccine needs to be stored at -94F, which presents challenges for rolling it out. (The Moderna vaccine can be stored in a typical freezer for up to 30 days, so logistically, it’s easier to work with.)
  • We don’t yet know when these vaccines will be widely available and how the rollout will work. There are many challenges with scaling them up. 

Derek Lowe wrote an excellent summary of what we know and don’t know about the vaccines. He covers both the good news and the questions that still need to be answered. This article in Politico covers the daunting technical and data challenges associated with vaccine rollout on a global scale. And this article in the New York Times discusses other obstacles we might encounter with scaling up production. 

The pandemic is out of control. It’s great to finally have a light at the end of the tunnel. On the other hand, we’re breaking records in the United States for the number of new cases and we’re getting close to records for the number of daily deaths. Healthcare systems in many states in the United States are overwhelmed, and it’s only going to get worse. Epidemiologist Trevor Bedford has shown that reported deaths from Covid lag behind reported cases by 22 days and that the case fatality rate (CFR) has consistently been 1.8% on a lagging basis since August. This means that we can somewhat accurately predict the number of deaths per day we’ll see in three weeks by looking at case numbers today—and those predictions are grim. If we reach 200,000 cases per day, which is entirely plausible, that would be 3,600 deaths per day about three weeks later. However, this CFR of 1.8% could increase as hospitals get overwhelmed and can’t accommodate everyone coming in. 

It’s time to buckle down. One of the potential downsides of the positive vaccine news is that people may let their guard down. This is a well-known psychological phenomenon in a situation like this. But what we really need now is to double down on protective measures so we can make it through this period where cases are exploding and we don’t yet have a widely available vaccine. A new study found that 130,000 lives could be saved over the next five months if 95 percent of Americans consistently wore a mask in public. Sadly, mask-wearing has become so politicized in this country that it’s virtually impossible that we’ll reach this goal.

Less masking, more infections. A New York Times survey in Louisiana found a direct correlation between attitudes toward wearing masks and infection rates. In places where people said they rarely/never wear a mask, infection rates were highest. Correlation is not causation, but these data fit well with what the large body of evidence supporting masks as a way to reduce transmission indicates. 

But wait, didn’t the Danish study prove that masks are worthless? No, it didn’t. It did find that wearing masks did not significantly reduce the risk of infection for the person wearing the mask, but it didn’t examine the question of whether wearing masks reduces the risk of infecting others (which, of course, is the primary reason we are advised to wear masks). There are some caveats, which are explained well in this write-up by Dr. Vinay Prasad. And, as public health authorities have argued all along, wearing a mask should not be viewed as a panacea; it is simply one of many interventions, along with distancing, hand hygiene, and ventilation, that can help. 

How do we fight Covid in a “post-truth” society? Fighting a pandemic is hard under any circumstances, but it’s nearly impossible when we don’t have a shared reality and can’t agree on basic facts. This week, nurses in South Dakota reported that they were being insulted and cursed at for wearing masks and other protective gear by patients with Covid who insisted that Covid did not exist—right up until when they died from it. Yes, this is happening—and sadly, it’s the world we live in now. 

Does a negative Covid test result mean it’s safe to gather indoors? The LA Times reported that some people in LA are getting tested on Thursdays, and if the results are negative, are attending dinner parties without masks on Saturdays. I recorded a video explaining why this is a bad idea and exploring whether we can use testing to make indoor gatherings over the holidays safe. (Spoiler alert: it’s really hard to use testing for this, at least for now.)

Even Sweden is abandoning the Swedish strategy. Hospitalizations are rising faster in Sweden than in any other European country, and they appear to be at least partially abandoning their own strategy of pursuing herd immunity. 

In health,


P.S. I’ve come to believe that the erosion of a shared reality is one of the most significant and dangerous problems we face. I recently discussed this topic with Tim Kendall from the Netflix documentary The Social Dilemma on my podcast. That episode should be ready soon. Stay tuned!