Obviously, my posts have become more sparse in the last few months, reflecting the reprieve we have had with COVID-19 in the spring and early summer. For a while, I contemplated closing this blog down in hopes that the worst had past. But I think I knew we were not out of the woods yet, and the Delta variant is confirming that unfortunate reality. After significant time without any hospitalized COVID-19 patients, our hospital has started to see an influx and has brought back status updates and contingency planning. 

I do not think most of us who have been seeing and treating patients during the pandemic are that surprised. I view this pandemic akin to an arms race. While we are administering vaccines, stockpiling PPE, and developing treatments, the virus itself is replicating, mutating, and adapting. Evolutionary pressure is extraordinarily strong and as I have alluded to in previous posts, the sheer number of viral particles out there means mutations will arise that increase infectivity, worsen severity, and evade our vaccines and therapies.

Furthermore, there's been a lapse in the social behaviors that protected our communities for so long. Indeed, simply being out in everyday life, I have seen a dramatic difference in our social distancing, indoor densities, and geographic mobility. I'm not sure if this was necessarily wrong, per se, because at the time, we weighed the risks and benefits to determine guidelines. But it seems we have run out of borrowed time. We need to adopt those risk-reduction behaviors again.

The crux of the issue is this. In medicine, we weigh each clinical decision by assessing its risks and benefits. The calculus changed significantly with vaccination, reducing individual and societal risk, allowing us to do more safely. But the Delta variant has reframed that risk-benefit analysis. The infectivity (R-naught) of this mutation is significantly higher, and comparisons have been made with chickenpox.

I believe we may be able to take a lesson from chickenpox. Like nearly everyone else my generation, I got the chickenpox in elementary school where it spread like wildfire. However, medical students today hardly see chickenpox at all because of a very effective vaccine developed in the 1990s. Even if a virus has a highly contagious R-naught value, we can tamp down outbreaks with widespread community immunity. 

There's a lot to say about the Delta variant. But what we know is that the vaccine is effective in reducing severe disease, hospitalization, and death, and we need to take advantage of that now. 97% of hospitalized COVID-19 patients are unvaccinated. The higher infectivity is ravaging unprotected communities. This wave is already here, and we need to act now. The best long-term tool we have is vaccination, but that will take time; we're already behind the ball because infections, hospitalizations, and deaths lag weeks behind exposures, and full immunity takes weeks to a month after a shot. Meanwhile, we need to mitigate spread with behavioral interventions.

The CDC has gotten criticism over these recent changes. Some say they liberalized their mask recommendations too early; others think this step back is premature; news reports find it confusing. From my perspective, it makes sense and feels necessary. At each point in time, we are weighing risks and benefits of each guideline, and they will change as the virus changes. If anything, the ups and downs of the past sixteen months argue that this may be the norm. So disappointing as it is, it's time to mask up and hunker down again to weather the storm.