What is the risk of death vaccinated against COVID?

The following essay is reprinted with permission from Conversationan online publication that covers recent research.

Fortunately, most people who become infected with COVID-19 do not become seriously ill, especially those who are vaccinated. But a small portion does end up in the hospital, and a smaller portion dies. If you were vaccinated and contracted a coronavirus, what are your chances of being hospitalized or dying?

How epidemiologist, I was asked to answer this question in one form or another throughout the pandemic. This is a very reasonable question, but it is difficult to answer.

To calculate the risk of hospitalization or death after SARS-CoV-2 infection, it is necessary to know the total number of infections. The problem is that no one knows exactly how many people have been infected with the coronavirus. Thus, although it is very difficult to assess the true risk of death if you are vaccinated and have contracted COVID-19, there are several ways to better understand the risks.

Counting infections

The first thing to consider when thinking about risk is that the data needs to be fresh. Each new option has its own characteristics that change the risk for those it infects. Omicron appeared quickly and seems to be going away quickly, so researchers or health officials had little time to collect and publish data that could be used to assess the risk of hospitalization or death.

If you have good enough data, you could calculate the risk of hospitalization or death. You will need to count the number of people who have been hospitalized or died and divide that number by the total number of infections. It is also important to consider the time delays between infection, hospitalization, and death. Performing this calculation will give you a true hospitalization of infection or mortality rate. Trouble in health officials don’t know exactly how many people got infected.

The omicron option is incredibly contagious, however the risk that this will lead to a serious illness is much lower compared to previous strains. It’s great that omicron is less serious, but it can lead to fewer people doing tests when they’re infected.

Even more complicated is the widespread use of test kits at home. The latter data from New York indicates that 55% of the population ordered them and that about a quarter of people who tested positive during the omicron surge used a home test. Many people who use home tests report their results, but many do not.

Finally, some people who develop symptoms may simply not be screened because they may not be able to easily access test resources or see no benefit in doing so.

If you combine all these factors, the result is that the official number of coronavirus cases in the United States is much less than the actual number.

Evaluation of cases

Since the beginning of the pandemic, epidemiologists have been working to estimate the true number of infections. There are several ways to do this.

Researchers have previously used antibody test results from large populations to assess the prevalence of the virus. Organizing this type of testing takes time, and as of the end of February 2022, no one seems to have done it for omicron.

Another way to evaluate cases is to rely on mathematical models. The researchers used these models to make estimates total number of cases as well as for mortality from infection. But the models do not distinguish between presumed infections of vaccinated and unvaccinated individuals.

Studies over and over again show that vaccination significantly reduces the risk of serious illness or death. This means that calculating the risk of death is really useful only if you can differentiate by vaccination status, and existing models do not allow this.

What is known and what to do?

Without an accurate estimate of the total number of vaccination status cases, the best available data are known cases, hospitalization and death. Although this limited information does not allow researchers to calculate the absolute risk a person faces, it is possible to compare the risk between vaccinated and unvaccinated people.

Most the latest data from the Centers for Disease Control and Prevention shows that hospitalizations are 16 times higher in unvaccinated adults compared to fully vaccinated, and the mortality rate is 14 times higher.

What to take away from all this? The main thing vaccination significantly reduces the risk hospitalization and death many times.

But perhaps the second lesson is that the risks of hospitalization or death are much harder to understand and study than you might think, and the same goes for deciding how to respond to those risks.

I look at the numbers and feel confident in the ability of my vaccination and revaccination against COVID-19 to protect me from serious diseases. I also choose a high quality mask when I am indoors with a lot of people to further reduce the risk and protect those who cannot get vaccinated.

Many lessons have been learned from this pandemic, and there are many things that researchers and the public still need to do better. It turns out that studying and talking about risk is one of them.

This article was originally published on Conversation. Read original article.