Myth No. 1
Masks protect against covid-19.
The stereotypical news photos from modern-day epidemics often show people in public places wearing masks. During the covid-19 outbreak, there have been mask shortages, presumably driven by widespread consumer belief in their effectiveness. In remarks on Feb. 29, President Trump sought to assure Americans, “We have 43 million masks, which is far more than anyone would have assumed we could have had so quickly, and a lot more are coming.”
All this despite evidence that commonly used masks, particularly typical surgical masks — essentially rectangular pieces of material connected to elastic bands — don’t prevent respiratory viruses among healthy people. Although a specific type of mask, the N95 respirator, is useful in protecting health-care workers and others caring for sick patients, it is not recommended for healthy individuals. Masks are, however, recommended for those who are sick to prevent transmission to others.
Myth No. 2
We will have a vaccine in the next few months.
Vaccines are extremely effective in controlling large outbreaks, which may be why the president and others in his administration have emphasized their supposedly imminent role in containing the current pandemic. At a public event in early March, Trump seemed convinced that a coronavirus vaccine could be ready in “three to four months, in a couple of cases.” Only slightly less optimistically, an NPR headline proposed: “Timetable For A Vaccine Against The New Coronavirus? Maybe This Fall.”
As a vaccine researcher, I wish this were true. There has been remarkable progress in creating a vaccine for covid-19. Several dozen development initiatives have been announced, and a candidate vaccine was recently delivered to the National Institutes of Health for human testing. Unfortunately, the vaccine is unlikely to be available for widespread use anytime soon.
First, candidates that seem promising in the laboratory are often found to not be effective (or in a few cases safe) in human trials. Second, before licensure and deployment, vaccines must be tested in progressively larger human trials. This process is likely to take several months to more than a year. Third, when a vaccine is found to be effective, it must be manufactured in very large quantities; scaling up production will take some time. The soonest we could expect a truly pandemic-controllingvaccine would be 12 to 18 months.
Myth No. 3
Travel restrictions are effective.
One of the measures the Trump administration enacted soon after the importation of novel coronavirus cases was a travel ban on foreign nationals who had recently visited China. It has since imposed similar restrictions on travelers from Europe. “Now, more than ever, we need the wall,” conservative activist Charlie Kirk tweeted Tuesday, referring to Trump’s proposed barrier at the southern border, despite the fact that cases are not entering the United States from Mexico.
The perception that such restrictions are effective is based on a simplistic understanding of how emerging infectious diseases spread. Travel bans are likely to be ineffective for covid-19 because in the time between the initial outbreak of the disease and the shutdown of travel from Wuhan, the virus is likely to have spread to a few other places undetected. So a passenger arriving in early February from Italy, a country that now has a widespread covid-19 outbreak that probably started several weeks ago, would not have been flagged.
The limited utility of travel bans is documented by mathematical models of influenza pandemics. In a study published in the Bulletin of the World Health Organization, examining the case of a virus even less transmittable than SARS-CoV-2, bans that shut down more than 90 percent of travel would be needed to have any impact. Even with these bans, there would only be a minimal impact on the total number of cases.
Myth No. 4
Covid-19 will be as dangerous in the U.S. as it was in China.
But in the United States the mortality rate, formally known as the case fatality ratio, is very likely to be lower than in China, and in many populations outside China it’s likely to be less than 1 percent. To get an idea of what we could face in the United States, it is reasonable to look at South Korea, which has fewer bottlenecks in covid-19 testing and, therefore, has good data. Right now, the estimate of mortality in South Korea is approximately 0.7 percent. Since fatal cases of covid-19 cause death three to eight weeks after the onset of symptoms, the South Korean case fatality rate might tick up a bit even as the outbreak wanes in that country.
But that doesn’t mean we should expect the same numbers in the United States. Fatality ratios depend on the specifics of a health system, such as the level of care provided and the ability to quickly expand the number of patients under treatment. Since conditions such as heart disease, cancer and other “comorbidities” are risk factors for severe outcomes with covid-19, fatality rates also depend on the prevalence of these illnesses in a population. Therefore, case fatality rates are variable and could be lower here depending on how we manage this outbreak. Sadly, this means mortality will be higher in low-income countries than in high-income countries.
Myth No. 5
We are helpless in the face of this outbreak.
As the capacity for laboratory testing expands in the United States, we will see a sharp rise in reported cases. This increase is likely to continue for several weeks, if not months. During a public health emergency, it is easy to feel paralyzed. “You’re Likely to Get the Coronavirus,” declared an Atlantic headline, capturing the general sense of inevitability. One Chicago Sun-Times columnist wrote that even expert information leaves him with the feeling that there’s nothing he can do.
But we are able to take effective action. For example, social distancing — public health strategies that reduce contact between people — can be effective in reducing the speed and impact of an outbreak. Social-distancing measures include canceling large events, closing schools, encouraging telecommuting and switching to online instruction in colleges.
Such measures need to be anticipatory rather than reactive. Since there is an incubation period before symptoms appear and patients seek care, today’s confirmed cases reflect virus transmission that occurred several days ago. Once a case is identified in a community or an institution, it might be too late.
We are also not helpless in the face of misinformation. We have the ability to obtain and disseminate facts by using credible sources such as the Centers for Disease Control and Prevention. When it comes to this novel coronavirus outbreak, we must seek truth as if our lives depended on it.