Epidemiologist Dr. Allen Johnson shares some insight with us this week into the COVID-19 situation and efforts to slow the spread of the virus.
Johnson is an assistant professor of public health and director of the Master of Public Health program at Rollins College. His wife, Dr. Asal Johnson, is an assistant professor of public health at Stetson University, where she has taught epidemiology and global health for the past six years.
The Johnsons live in DeLand.
Q: Many people want to compare this with the ordinary flu, and they question why such a big deal is being made about COVID-19, when raw numbers would indicate the flu is more prevalent and possibly even more deadly. Why are they wrong?
A: Most of what is being reported are raw counts. Although important, putting these numbers in context provides a more in-depth picture about what is going on.
The first context we need to consider is time. The coronavirus outbreak essentially has just begun in much of the world. The numbers we are seeing today are just the beginning.
In the U.S., New York is like looking into the future. Because this is a new virus, we simply do not know how long this may go on for, although we can make some predictions based on certain scenarios.
The seasonal flu, on the other hand, has a very predictable time frame. So, at this point, raw counts of flu cases or even deaths from last year, for instance, may be higher; however, this is because the duration of the two are different.
The flu season typically lasts around six months. Once the coronavirus pandemic runs its course, we will have a more accurate account of the extent of it.
Q: Are there other differences between COVID-19 and the flu?
A: The other main difference between the seasonal flu and COVID-19 is that COVID-19 is much more deadly.
Again, when comparing raw counts, flu may appear more deadly. Although at this point, the actual number of deaths for flu may be higher because, as mentioned, the coronavirus epidemic has essentially just started, this is misleading.
In public health, we determine how deadly a disease is by a measure called the case-fatality rate. This is the percentage of people that will die that get the disease. On average, 0.1 percent of people who get the flu die, or about 1 out of every 1,000 that get the disease.
Based on the numbers we have today, for COVID-19, around 4.5 percent of people that get the disease will die. That means out of every 100 people that get the disease four or five of them will die. This is very high and should cause great concern.
The last main difference is that there is a vaccine and treatment for the flu. The vaccine helps prevent many people from getting the disease.
For people not vaccinated and who get the flu, there are medications available that help reduce the severity of the disease. To date, there is no vaccine or proven effective treatments for COVID-19, although research on both is ongoing.
Q: Can you go into more detail about what’s different about COVID-19 than, say, pneumonia or the flu that we’re used to seeing?
A: Pneumonia is a general condition of the lungs where fluid builds up due to an infection. This infection can be caused by a virus, such as COVID-19, or bacteria or even fungi.
Typically, when someone has pneumonia, it is caused by a bacterial infection, and it can be treated with antibiotics. One of the symptoms of COVID-19 is pneumonia.
The primary difference is that there is no treatment for pneumonia caused by COVID-19 because it is a new virus. In severe cases, the fluid in the lungs builds up so much that you essentially drown in your own fluids.
Q: Can you explain what is meant by a “novel” coronavirus?
A: Coronaviruses are a group of viruses with some similar characteristics. Some coronaviruses are human viruses and cause some of the common colds we see every winter.
Other coronaviruses are animal viruses that typically cannot infect humans. Sometimes these animal viruses change in a way that allows them to infect human cells. These are considered “novel” viruses because they are new to humans.
This was the case for SARS, MERS and COVID-19. All three of these viruses originated in bats and changed at some point, allowing them to infect humans and be transmitted person-to-person.
Because COVID-19 was previously unable to infect humans, we have no natural immunity built up from prior exposures, causing the disease to be more severe.
Q: Is it true that if everyone in the world isolated themselves completely for 14 days (or some other number), we could end this immediately? If so, why would that work?
A: Yes, although the exact duration is debatable. If you could wave a magic wand and have everyone stay in their homes except for people providing the most basic services for survival, such as the people that operate our water systems, sewage systems, and the electric grid, emergency response personnel such as firefighters, law enforcement and paramedics, and health care workers, the epidemic would end.
This is because transmissions would be severely reduced, and everyone infected would develop the disease within that time period and be transported to hospitals for treatment.
The problem with this is we don’t have a magic wand. What we are seeing instead in the U.S., and much of the world, is more of a patchwork approach where different states, counties and cities are doing different things.
Also, keep in mind that this is a global pandemic. Therefore, even if one country, or state, was able to do this, the virus would still be spreading in other locations and would likely become epidemic again in that country after the measures were lifted.
There must be a coordinated effort across countries and by the federal government here in the U.S. to ensure our approach is consistent across different locations.
Unless there is strong leadership at the federal level to effectively coordinate consistent, evidence-based effort across the entire U.S., we will have a hard time containing the epidemic.
Q. Isn’t it also true that, ultimately, the world population needs to develop “herd” (that may not be exactly the right term) immunity to COVID-19? How can that happen, if we prevent ourselves from being exposed?
A: There seems to be some misunderstanding about herd immunity.
Herd immunity is a concept we use to effectively implement vaccination programs. Because a very small number of people cannot take vaccines for medical reasons or have legitimate religious objections (for instance, the Amish), we are unable to vaccinate everyone.
We then must reduce the probability that a non-vaccinated person that gets the disease comes into contact with another non-vaccinated person, effectively preventing the disease from spreading in the general population.
Typically, this requires around 95 percent of the population to be vaccinated. This is known as “herd immunity.”
There seems to be a narrative going around that you can achieve herd immunity through people catching the virus.
Keep in mind, the whole concept is based on preventing people from getting the disease through immunity acquired by vaccination.
For 95 percent of the world’s population to get the disease is not herd immunity, that’s simply a full-blown pandemic of monumental scale where hundreds of millions of people will die and every aspect of society would break down.
Public health is about preventing disease and death. That’s not public health, that’s public disease.
Q. If you get COVID-19, will you then be immune?
A: It is unclear at this point that you develop immunity after recovering from COVID-19.
Some new research out of Japan suggests that people may get infected again after they have recovered, although it is too early to know for sure.
At this point, there is no vaccination, although there is ongoing research to, hopefully, develop one.
Without a viable vaccine that is readily available, herd immunity is not an option.
Q: Across the globe, are we seeing examples of a successful approach to dealing with this? Where, what, how?
A: The two main success stories during this pandemic, if you could call them that, are China and South Korea. They had different approaches to this success.
Because the pandemic started in China, very little was known about the virus and no tests were available during the early stages.
China took steps fairly quickly to impose total isolation by law for the citizens of the affected area. A test was eventually developed, and they began testing people at that point.
The mandated isolation in China effectively stopped the spread of the virus.
It is important to point out, however, that China has a government structure that is readily able to implement these types of measures and a citizenry more willing to comply. This is not the case for many countries around the world, including the U.S.
The epidemic started in South Korea a little later than in China, and they were able to start a mass testing campaign very early on.
This was coupled with aggressive contact tracking; whereupon, they would identify everyone an infected person came into contact with and test them. Then they would contact everyone they came into contact with and test them, and so forth.
In public health, we refer to this as contact tracing. Because they started this very early on, it has been effective at controlling the epidemic and, so far, there has not been a need to implement widespread isolation policies.
Because we are now so far into the epidemic in the U.S., and much of the world, to effectively control the epidemic, we will need to have a combination of the two approaches.
The problem with the U.S. response so far is that we have not done either one very well.
Q: What’s your best guess at how long this will take to work through society? In other words, when maybe, maybe, we might get back to “normal”?
A: It’s hard to say. Everyone should expect things to get a lot worse before they get better. I do not think it is realistic to think in terms of weeks; rather, we are likely talking about months.
As difficult as this is, it is important to not relax public health policies too early, or we will lose all the gains we have made.
Q: What kinds of things are you and your family doing to be safe? Can you share your opinion about masks, gloves, hand sanitizers, etc.? What are the best things we can all be doing?
A: It is important to take public health recommendations and policies seriously, particularly by social distancing and self-isolating when possible. We really don’t know if people that are infected but don’t have symptoms yet can spread the disease.
Also, many people with COVID-19 may have mild symptoms and mistake it for a cold or allergies. Because of a shortage of tests, we are primarily testing sick people, and we can assume that there are a lot more people out there that have the virus but are not sick yet and may not be for a week or so.
It is also very important to regularly wash your hands with soap and water. Any soap is effective.
What I tell my kids is to sing their ABCs while washing their hands before they run them through the water. This should be enough time to remove any potential virus that is on your hand.
If you have them, masks and gloves are good if you must go to public places where you may interact with people in close contact. They are probably not necessary if you are strictly practicing social distancing of at least 6 feet and washing your hands regularly.
Q: What should readers understand about the scientific methods and models being used to recommend best practices at this time?
A: Because there is so much information being circulated and a lot of confusion, it is very important that the information you are receiving is accurate. It is important to listen to scientists and public health experts.
Unfortunately, there is much we do not know about some of the specifics about the virus, its transmission, how the pandemic will unfold, etc.
I know this can be frustrating to people in a time of uncertainty. It’s understandable that people will seek out answers from other sources that may provide more definitive claims, as inaccurate as they may be.
People should resist this, and trust the experts.