I had a blog post on another topic half written, but the rise in new COVID-19 cases in the United States over the last 2 weeks is too shocking and dangerous to ignore. Texas, Florida and California are all stepping back reopening plans and returning to previous restrictions. In my opinion, that was the right call to make. But I wish it hadn’t taken hundreds of thousands of cases and 20,000 U.S. deaths in the month of June alone for them to act.
COVID-19 isn’t taking a summer vacation. It hasn’t gone south of the equator to colder temperatures, and despite what some might like you to believe summer UV rays are not killing it. Believe me, I wish this were an ordinary summer, and that my family and I could go about our usual summer vacation activity without worrying about a pandemic. But that’s just not the world we live in anymore. It isn’t. We need to get back to the steps that helped control COVID-19 earlier this year and that will do so again if we stick to them.
The first step I’m going to address is face mask wear.
Face masks aren’t a cure-all, and certainly aren’t a replacement for stay-at-home, isolation or quarantine orders. If your state or local government has issued a stay-at-home order, if you’ve recently been exposed to COVID-19 and have been told to quarantine or if you have COVID-19 and have been told to isolate, then listen to your doctor or health department. Stay home. We are all relying on you.
This post is intended for people who aren’t under stay-at-home, isolation or quarantine orders: people living in areas that are reopening or who are essential workers and have to leave their homes to go to work. Please. Wear your masks any time you can’t stay at least 6 feet away from other people.
I know we’ve heard a lot of conflicting information about face masks over the last few months. Earlier this year, the CDC told us that the general public didn’t need face masks and to save the limited supply for healthcare workers. Now we’re asking everyone over 2 years of age to wear face masks.
Those changing recommendations reflect the nature of science, particularly when dealing with something new like COVID-19. There were a lot of unknowns earlier this year, and there still are many unknowns now. But in a dangerous outbreak – and make no mistake, COVID-19 is incredibly dangerous – we cannot wait until we have all of the answers to make a recommendation. Experts have to make recommendations based on the best available evidence. As we learn more, sometimes the best available evidence changes and smart experts change their recommendations to reflect the new evidence.
But the initial uncertainty about whether masks work doesn’t mean that experts are still uncertain. One of my favorite things about scientists is that when they see that an important question hasn’t been answered, they rush in to answer it. We now have multiple studies that show that masks do work to control COVID-19.
Let’s talk about what those studies show.
A study by investigators from the University of Iowa, published online at Health Affairs in advance of print publication, compared rates of increases in COVID-19 cases (growth rates) before and after mandates for face mask wear in public were signed in 15 states plus the District of Columbia. They found that overall, the growth rate dropped by 1 percentage point within 1 week of the public face mask mandate and by 2 percentage points within 3 weeks. In comparison, rates had not significantly changed before the mask wear mandates – suggesting that mask wear contributed to the decline in the growth rate. While a 1 or 2 percentage point change might not sound like much, bear in mind that the decline was statistically significant at every point measured after the mask wear mandate, but never significant before.
The same study also looked at 20 states that issued requirements for only certain employees to wear face masks. They found no significant benefit to employee-only mask mandates. In other words, for masks to be effective, everyone (or just about everyone) needs to wear them while in public. That study estimated that public face mask requirements prevented between 230,000 – 450,000 cases of COVID-19 by May 22. If COVID-19 kills between 0.5% – 1% of people infected (scientists still aren’t entirely sure of COVID-19’s death rate, but that seems to be the best estimate to date), then that could be 1,150-4,500 lives saved by wearing masks for only a few weeks.
Another multi-agency study published online in advance of print publication at Medrxiv compared COVID-19 mortality (death) rates in countries with and without societal support or early government recommendations for face mask wear. In countries recommending masks, deaths rose by 8% each week. In countries without mask wear, deaths rose by 54% each week.
A 54% increase in deaths in one week means that deaths doubled just less than every 2 weeks. At a rate of 8% increase per week, deaths would double every 10 weeks.
Let that sink in. Countries that didn’t have face mask recommendations had death rates more than five times that of countries that did.
The case for face masks gets even stronger, though: Figure 1 of that same study compares the death rates in countries with and without mask wear recommendations. In countries that recommended face masks within 2 weeks of the start of their COVID-19 outbreak, the death rates were so low that viewers nearly cannot tell the line illustrating their death rates apart from the line for 0 deaths.
A study published on June 1, 2020 in The Lancet, one of the most prestigious medical journals in the world, did a systematic review and meta-analysis (a statistical comparison of many studies) of 172 studies across 16 countries and 6 continents on methods to prevent coronavirus spread. The researchers found a strong effect of face masks on preventing coronavirus spread. N95 or similar respirators were the most effective, but surgical masks or similar reusable cotton masks reduced the odds of catching coronavirus by about two-thirds.
Finally (not the only other study on face masks, but the last I’ll discuss today), a fascinating video published in the New England Journal of Medicine on May 21, 2020 shows exactly how much face masks reduce the spray of droplets we all make while we’re speaking. Researchers used a green laser to light up the droplets sprayed when a man said “stay healthy” while and while not wearing a face mask. When he spoke without a mask, the screen lit up like fireworks. With a mask, the droplets were barely visible. Please, take a few seconds to watch that video. It might change the way you think about masks and how we speak.
Personally, that’s plenty convincing to me. Face masks reduce the spread of droplets that may carry the virus that causes COVID-19, they reduce odds of catching COVID-19 and similar viruses, they reduce cases and deaths due to COVID-19. In fact, a recent analysis by the Institute for Health Metrics and Evaluation predicts that if 95% of people wore face masks while in public in the U.S., we could prevent 33,000 U.S. deaths due to COVID-19 by October 1, 2020.
But then again, I’m a public health physician; preventing disease is kind of my “thing”. Some people need a bit more convincing as to why they should protect other people. If they are young and they are healthy, the argument goes, then they’ll be fine and needn’t worry about catching COVID-19 for themselves, and why should they worry about other people?
First of all, I would be shocked if you truly don’t know and care about any older adults or anyone else at high risk for COVID-19. Maybe you have older parents, grandparents, neighbors, coworkers or professors. Maybe you have a friend or family member with COPD, diabetes, sickle cell disease or heart disease. Do you have any friends or mothers of your kids’ friends who are pregnant? All of these group are or may be at high risk of severe COVID-19 disease. Don’t they deserve to be protected?
But even if you are young and healthy and don’t know anyone at high risk, you may still be at risk yourself. Half of the new cases of COVID-19 in recent weeks have been among adults under age 35. While it’s true that most cases among young adults are mild or asymptomatic, over 3% of COVID-19 deaths in the U.S. have been among persons under 40. That might not sound like a lot, but out of over 120,000 U.S. deaths reported as of today, that comes out to over 4000 deaths in younger adults and children.
We are all at risk. Protect yourself. Protect your loved ones. Protect your community. Wear a mask.
😷 Dr. B