The following essay is available for re-publication in The Conversation, an online publication covering the latest research.

Most people who get Covid don't become seriously ill. A small fraction get hospitalized and a small fraction die. If you catch the coronaviruses, what are your chances of getting hospitalized or dying?

I have been asked to respond to this question in a variety of ways. This is a very reasonable question to ask, but it is difficult to answer.


You need to know the total number of infections to calculate the risk of hospitalization or death. Nobody knows how many people have been affected by the coronaviruses. It is hard to estimate the true risk of dying if you are exposed to COVID-19, but there are ways to better understand it.

Counting infections

Fresh data is the first thing to consider when thinking about risk. Each variant has its own characteristics that affect the risk it poses to others. There has been little time for researchers to collect and publish data that can be used to estimate the risk of hospitalization or death because Omicron came on quickly.

It is possible to calculate the risk of hospitalization or death if you have good data. You need to divide the number of people who died or were hospitalized by the number of infections. Time delays between hospitalization and death are important. The true hospitalization or fatality rate would be given by doing this calculation. The problem is health officials don't know how many people have been affected.

The risk of the omicron variant causing significant illness is much lower than previous strains. It is great that omicron is less severe, but it may lead to fewer people seeking tests if they are exposed.

The availability of at- home test kits is complicating things. According to recent data from New York City, 45% of the population ordered these and a quarter used a home test. Many people who use home tests do not report their results.


Some people who get symptoms may not get tested because they can't easily access testing resources or they don't see a benefit in doing so.

The official count of coronaviruses cases in the U.S. is far lower than the actual number.

Estimating cases

Epidemiologists have been working on ways to estimate the true number of infections. There are several ways to do this.

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The prevalence of the virus has been estimated using results from large populations. It doesn't appear that anyone has done this for omicron because of the time it takes to organize this type of testing.

Another way to estimate cases is using mathematical models. Researchers have used these models to make estimates of the total number of cases. The models don't distinguish between the estimated infections of vaccine and unvaccinated individuals.


Research shows that vaccinations greatly reduce one's risk of serious illness or death. The risk of death calculation is only useful if you can distinguish between vaccination status and other variables.

What’s known and what to do?

The best data available is known cases, hospitalizations and deaths, because there is no good estimate of total cases by vaccination status. It is possible to compare the risk between vaccine and unvaccinated people because of the limited information.

According to recent data from the Centers for Disease Control and Prevention, the rates of hospitalization and death for unvaccinated adults are 16 times and 14 times higher, respectively.

What can we take away from this? Vaccination greatly reduces the risk of hospitalization and death.

The risks of hospitalization or death are more complicated to understand and study than you might have thought, and the same goes for deciding how to react to those risks.


I feel confident in my ability to protect myself from severe disease because I look at the numbers. I wear a high-quality mask when I'm indoors with lots of people to make sure I don't expose myself to more risk and to protect those who can't get vaccine.

There have been many lessons learned from the Pandemic and there are still many things that need to be improved. Talking about risk is one of them.

The Conversation published this article. The original article is worth a read.