‘Tis the season for year-end reflection. I imagine many of us are just as happy to put 2020 in our rear view mirror without further adieu. If that’s you, feel free to carry on your way with my blessing. For the rest of us, I have a couple thoughts on what has transpired from the past 365 days and what we might fruitfully carry forward. I’ve covered a variety of topics this year, in part to give us all something to think and talk about besides the pandemic, but at the end of the day/year I’m a public health scientist with an emphasis on infectious diseases, so that’s where I’ll focus now.
First and foremost, the biggest positive from 2020 is the extraordinary speed and effectiveness with which multiple SARS-CoV-2 vaccines were developed. One year ago, we did not know the identity of the virus causing unusual clusters of pneumonia in China, and today people around the world are receiving injections of several potent vaccines, with more candidates likely on the way to bolster our manufacturing throughput. While these deliveries are still in very early days and second doses are still to come for the first recipients, the numbers are such that lives likely already will have been saved.
Initial authorizations went to mRNA vaccines, the first such vaccines to be authorized for human use. Other vaccines deliver the target pathogen itself or some pieces of it; mRNA vaccines deliver the instructions for how to make those pieces for our own cells to assemble. In this case, those instructions are for just part of one protein, the spike that gives the coronavirus its distinctive namesake shape. At no point is the whole virus involved, so there is no risk of the recipient developing an infection that could make them ill or be spread to others. The polio vaccine, by contrast, involves a live virus modified to not cause disease, but mutations can occur when that vaccine virus replicates in a recipient that make it more pathogenic and capable of causing outbreaks. Thus mRNA vaccine technology holds out the promise of safer vaccines for present and future pathogens.
Remarkably, in one sense these vaccines were assembled in a matter of days, once the SARS-CoV-2 viral genome was published. The vaccines now being administered have existed since as early as January; all of the time in between has been spent testing them to make sure they are effective and as safe as we can reasonably assess without giving them to everyone. In another sense, however, these vaccines have been many years in the making. Vaccines based on mRNA for a variety of diseases have been created and tested in multiple settings, including animal experiments and small, early phase human clinical trials. Some of these vaccines targeted the related coronaviruses causing SARS and MERS, but they never received final approval because there is not enough active transmission (in the case of the SARS virus, none) to make a large-scale clinical trial possible.
Valuable lessons relevant to the SARS-CoV-2 vaccine were learned from this research, particularly from the SARS vaccine studies. Using the whole spike protein prompted mice to make antibodies that actually helped the virus bind to its receptor and exacerbate infection. Researchers found that they could leave off one end of the spike protein and prevent that scenario, but then the spike protein also didn’t bind to itself the way it does in the actual virus. So they replaced that end with another bit of completely unrelated protein that restored self-binding without exacerbating infection. These lessons have been incorporated in several vaccine candidates, meaning we have benefited from years of preparatory work that no one at the time could have known for certain would ever yield dividends. Basic, open-ended research continues to be vital for innovation. So for everyone investigating how the world works without a definite path to practical application, we see you and value your work and thank you for it.
Second, it is my hope and prayer that 2021 and beyond bring greater awareness of the value of public health, and perhaps with it greater investment. Here I don’t just mean our formal public health institutions, but the common good that is our health as communities. We’ve seen how simple measures like wearing masks can positively impact respiratory illness; we could incorporate some version of these in common practice going forward. Infrastructure for widespread testing could lessen the need for cruder measures liking sweeping stay-at-home orders. The public has learned more about herd immunity; perhaps that could lead to greater uptake of the annual influenza vaccine. All of these changes could reduce the disease burden of pathogens we know we will need to deal with every year, as well as prepare us better for future pathogens we haven’t encountered yet.
Relatedly, this pandemic has highlighted and hopefully raised awareness of the reality that health and healthcare are not equally accessible to all people in the United States. Indigenous peoples and other communities of color have been disproportionately impacted. There are multiple causes for these disparities. One is higher rates of chronic diseases like diabetes in these communities, chronic diseases which increase risk for more severe COVID-19 outcomes. Those higher rates are themselves the product of various systemic inequalities. Another cause of COVID-19 disparities is simply that more members of those communities work in jobs that cannot be done remotely, in some cases with inadequate paid sick leave. These inequalities were worthy of redressing before the pandemic, but hopefully the greater awareness will spur faster and more systemic action.
Thanks for reading along with these thoughts and all of my musings in 2020. I hope 2021 is a healthy and fruitful year for all of us individually and as communities.