As the US approaches the second half of 2021, amazing progress against COVID-19 has been made. Most of the adult population has received at least one dose of vaccine and case rates have fallen substantially. Though the potential for seasonal spikes and new variants of concern remain as issues, it appears the worst of the pandemic is behind us in the US.
I feel that we were lucky. It seems wrong to write that for a disease that has claimed approximately 600,000 American lives, causes lingering effects in many people, and both harmed and altered the economy in ways that are still being assessed.
However, it could have been much worse. An illness that combines the infectivity and asymptomatic spread of COVID-19 with the lethality of SARS-CoV-1 would have been beyond devastating.
Despite many missteps in our COVID-19 response, the US hit a grand slam with vaccine development. The widespread availability of COVID-19 vaccines across
the country makes it easy to forget that these agents became available only a few short months ago.
Any one of the many steps in vaccine development could have gone wrong. Although not every vaccine that entered clinical trials was successful, multiple agents were, and they have efficacy that is well above the expected threshold to limit spread. Safety of our available vaccines is now well understood and severe adverse events are exceedingly rare, particularly for the mRNA vaccines.
The spike protein of SARS-CoV-2, which is the antigen targeted by every single one of the vaccines currently available, turned out to be an effective target for vaccine-induced neutralizing antibodies. The US government funding of several vaccine manufacturer programs led to useful vaccines (with others still possible), and the “go-it-alone” approach of Pfizer led to another success.
Imagine some scenarios where things went differently. In one, multiple vaccines were not efficacious, and the one that succeeds in a trial has a measured efficacy of 50% but only for severe disease and only mildly blunts asymptomatic disease, leading to a limited effect on decreasing transmission. Vaccine availability is low due to high demand and limited production capabilities. Deaths decrease, but the pandemic rages.
Or, an approved vaccine is effective, but has a less-safe adverse effect profile that causes severe adverse effects in 1000 times as many people as the current vaccines. The adverse effects are still much rarer than deaths from COVID-19, but due to a different risk-benefit balance, only older adults and health care practitioners receive it. Deaths decrease, but the pandemic rages.
Or, imagine if the spike protein ended up being a poor target after all. Every single vaccine currently on the international market would fail. The pandemic rages.
None of these scenarios occurred. We are on track to control a rapidly emergent pandemic through vaccination for the first time in our history. It has not been easy, and because we have not implemented the more basic tenets of public health for infectious diseases well, we are fortunate. Humans have a tendency to forget history’s lessons as crises abate, and this is where I fear we are learning the wrong lesson now.
A process that began many years ago with vaccine development on multiple fronts culminated in the amazing therapeutics that we are putting into arms now. It is an enormous success. We cannot assume that the next challenge will be addressed successfully with technology at the same pace. The time to fund disease surveillance, bolster scant public health infrastructure, and develop our ability to respond to novel viruses is now, before the next shiny object takes our focus away.