This is one-half of a point/counterpoint pair of articles regarding the need for infection-control precautions by people who’ve received their full COVID-19 vaccinations. Here, David Aronoff, MD, argues that now is not the time to lower our guard, vaccinated or not. Click here for the viewpoint from Vinay Prasad, MD, MPH, who says relaxing some restrictions after vaccination will be OK.
The COVID-19 pandemic has now raged on for more than a year. In the U.S., we have documented more than 24.5 million cases and 400,000 COVID-19-related deaths, with between 3,000 and 4,000 people dying each day. The CDC projects we will reach nearly 500,000 total deaths within the next month. COVID-19-related hospitalizations remain at an all-time high. America continues to suffer through a third wave of disease activity that has dwarfed the peaks of the Spring and Summer of 2020.
And, while COVID-19 is beating down on us, it could be worse, believe it or not. We have learned much about how the SARS-CoV-2 virus spreads, easily, through our breath from one person to another. Most nefarious has been the extent to which transmission occurs silently, moving from infected individuals who feel well, look well, and have no idea that they are infected. However, we know that maintaining our distance from others protects against transmission, as does the use of cloth face-coverings. It has been through social distancing and mask use that we have, in the absence of vaccination and herd immunity, been able to limit the damage done by this horrible infectious disease.
Clearly, vaccines against SARS-CoV-2 are the light at the end of the tunnel, assuming that viral mutations do not escape our vaccines sooner than we can put out the fire. With estimates that more than 60% of the population will need to have immune protection against SARS-CoV-2 to benefit from herd immunity, we have a long way to go. While less than 10% of the U.S. population has been formally diagnosed with COVID-19, a recent estimate suggested that by November of 2020 we were at about 15% of the U.S. population immune to the virus. And while that figure may now exceed 20%, this leaves more than 250 million Americans without immune protection, and falls short of the roughly 200 million people who might need to be immune for herd immunity to take hold.
Vinay Prasad, MD, MPH, has authored a thoughtful, evidence-based commentary, making a strong case for why we can relax some restrictions following successful immunization against SARS-CoV-2. He succinctly lays out an argument about why and how immunization, in the absence of vaccine-escaping virus mutants, will confer strong enough protection to render tight adherence to wearing masks and other restrictions unnecessary. And, while I think he has the right idea (I would love to see more people’s faces right now and share a meal with my friends), it is premature to suggest that now is that time. It is OK for us to hold differing opinions (that’s what we do). Two well-intentioned scientists can both look at the same data and reach different policy conclusions. So, let me focus on the case for keeping our masks on, even as we roll our sleeves up. The same logic holds for other restrictions.
First, given how active COVID-19 is right now we need to be doing everything in our power to slow its spread. Lives hang in the balance. I really like the Swiss Cheese model of pandemic defense, popularized by Australian virologist Ian Mackay, PhD, which demonstrates the concept that each measure we implement to interrupt the SARS-CoV-2 pandemic is imperfect yet when layered together they cooperatively reduce transmission risk.
Even immunization is not a perfect defense. Thus far, SARS-CoV-2 vaccination has not been shown to eliminate the risk that someone will get infected or pass the virus on to others. Studies published to date on the Moderna and Pfizer-BioNTech mRNA vaccines show clear protection against developing symptomatic COVID-19. But they also show that some vaccinated people still develop symptomatic disease. And, given what we know about the disease in non-immune people, symptomatic infections represent a fraction of total infections. This predicts that despite immunization some people will develop asymptomatic infection. Do I think that SARS-CoV-2 immunization will significantly protect people against both asymptomatic and symptomatic COVID-19? Yes. Do I think the risk to an individual will be zero following successful immunization? No. Stated differently, removing masks from vaccinated people (or relaxing social distancing) is likely to increase the risk for propagating COVID-19 compared to maintaining these restrictions. And, even if that incremental risk is small, why take it, given where we are with the disease now?
There will be a time when immune people can let their guards down, allowing even non-immune people to do the same (a benefit of herd immunity). But that time is not now.
The issue of wearing masks has been a contentious one, not helped by mixed messaging from leaders in the federal and state government. This has translated into story after story of difficulty convincing people of the public health benefit of wearing face-coverings. What we do not need are more people out and about in public spaces without masks, which sends the wrong message at the wrong time. We cannot know if an unmasked person is unvaccinated or simply an anti-masker. Why provide fuel for people to skirt mask policies based on stating they have been vaccinated, when they might not have been? And the same holds for hosting dinner parties or participating in other gatherings.
To safely advise people that once they are immunized they can leave their masks at home and relax other infection control measures we need to record sustained decreases in disease activity, hospitalizations, and deaths, to the point where leading infectious disease and public health experts are comfortable recommending that we can deescalate these interventions. We also need to ensure widespread vaccine uptake, particularly among Black, indigenous, and people of color, who have been disproportionately harmed by COVID-19. Recent data show that Black Americans, for example, are getting vaccinated at lower rates than white Americans.
We remain in the thick fog of a true healthcare emergency and need to be doing all we can, especially the simple things, to shut it down. Now is not the time to let up on masking, even for the relatively few who have been immunized. Abandoning mask-wearing and social distancing, even in immunized persons, is not the right thing to recommend, yet. We need masks on and sleeves up.
David Aronoff, MD, is director of the Infectious Diseases Division in the Department of Medicine at Vanderbilt University in Nashville.