Answers to frequently asked questions about the omicron variant and COVID-19 vaccines

UI Health Care infectious disease specialists Daniel Diekema, MD, and Patricia Winokur, MD, answered questions about the omicron variant, COVID-19 vaccines, and other topics during a live Q&A on Jan. 14, 2022.

The following is a summary of the answers provided by Dr. Diekema and Dr. Winokur.

How is the omicron variant of COVID-19 different from previous variants?

First, let’s explain why we even care about these variants. We are very interested when the variant: 

  • Increases transmission from person to person 
  • Causes more severe disease 
  • Evades our vaccines or evades the treatment options we have 
  • Can't be diagnosed as readily, because our tests don't work 

The omicron variant of COVID-19 has more mutations than any of the previous variants we've seen before. We are seeing that the omicron variant is more transmissible, meaning it is going from person-to-person more quickly. Right now, it seems like the omicron variant of the virus likes to replicate more often in the nose and throat, and less often in the lungs. This is good news, because it is causing less severe disease.

What does the data say about the importance of COVID-19 vaccines, specifically with regards to safety and effectiveness?

The COVID-19 vaccines have been studied for very close to two years now. The evidence shows that these are some of the safest vaccines we have available. We have very few severe side effects with these vaccines, and we are not seeing anything popping up now, two years later after people have gotten these vaccines, so that's great news. 

Throughout the pandemic we’ve seen that the COVID-19 vaccines are very effective at preventing serious illness. When people are fully vaccinated, they are less likely to be hospitalized or end up in the intensive care unit. With omicron, because there are more mutations than any of the previous variants we’ve seen, the vaccines are not quite as good at preventing infection. But the vaccines are very effective in keeping you out of the hospital. These are still very safe and effective vaccines. 

Get more information about the COVID-19 vaccines and booster shots.

Why are some people who are fully vaccinated, even those who have had a booster shot, still getting infected with COVID-19?

We’ve seen that the COVID-19 vaccines create antibodies that are effective against previous variants. Because the omicron variant has mutations that we’ve not seen in previous variants, the antibodies created by the vaccines are not quite as effective at preventing infection as they were with previous variants. 

One key factor is when you were vaccinated. We know that the level of antibodies in your blood decreases over time, either after vaccination, or after infection. After five months, the titers (the blood tests showing the level of these antibodies) have dropped, and there are more breakthrough infections. The first two doses of the vaccine (with Pfizer-BioNTech and Moderna) create a certain level of antibodies to protect you. When you receive the booster shot, the antibody numbers skyrocket and the level of protection improves again. That booster shot is really important for preventing infection with the omicron variant and reducing the severity of the illness, if you do get sick. 

Related: Learn more about why vaccinated people can still get sick with the omicron variant.

Some of the symptoms of COVID-19 are similar to the flu or the common cold. When is it recommended that people get a COVID-19 test?

COVID-19 symptoms can vary quite a bit from person to person. Any symptom you would normally think of as being flu-like or cold-like is an indication that you could have COVID-19, and you should seek a test. These symptoms include: 

  • Sore throat 
  • Sinus congestion 
  • Cough 
  • Fever 
  • Headache 
  • Extreme fatigue 
  • Loss of taste or smell 

We also recommend getting tested after you have been around someone who you know had COVID-19. This could be someone you live with or someone that you were within six feet of for more than 15 minutes.  

The recommendation is to get tested on the fifth day after that exposure, while you're monitoring your symptoms. If you are fully vaccinated and boosted, you can still go out of your house while wearing a mask and keeping other safety precautions in place. If you aren't fully vaccinated or boosted, public health authorities recommend that you stay at home for at least five days in quarantine until you get that test.  

Related: Learn more about the difference between a cold, the flu, and COVID-19.

There are many types of COVID-19 tests available. Could you explain the options and how they differ?

There are three main types of COVID-19 tests: 

  1. Antigen tests look for proteins from the virus, from a sample, usually taken from your nose or nasopharynx.  
  2. PCR tests look for genetic material from the virus. 
  3. Serology tests look for antibodies against the virus that are present in your blood. 

Most of your at-home tests are antigen tests. These tests are most likely to be positive or most sensitive when you have high levels of virus in your nose and throat. This also happens to be the time when you're most likely to transmit the virus, so the antigen test can be very useful when you're having active symptoms or shedding a lot of virus. However, they're not as sensitive as the PCR tests. 

PCR tests are considered the gold standard tests for diagnosing COVID-19. PCR tests are mostly analyzed in hospital laboratories and are very sensitive tests. The downside is that they can sometimes detect genetic material from the virus that's being shed from your lungs, throat, and nose for weeks and weeks after your infection. 

Serology tests are not that helpful to determine if you are actively infected. These tests are used mostly for epidemiologic studies to determine how many people have been exposed to the virus within a given population. 

All these tests need to be interpreted with caution. If you take an antigen test because you have symptoms of COVID-19 and it's negative, you should still get a PCR test, because PCR tests are the most sensitive tests.

What other safety precautions should Iowans be taking right now, and does vaccination status impact any of those decisions?

The number one thing is to get vaccinated if you haven't been vaccinated and get boosted if you are eligible for a booster. It can't be emphasized enough—the booster dose is very important to protect against the omicron variant. 

Secondly, wear a mask in public, even if you are fully vaccinated. Medical-grade masks are now recommended instead of cloth masks. If you are still wearing a gaiter or a cloth mask that's a single layer, it’s time to consider upgrading to a medical-grade mask. 

Most importantly, make sure your mask fits snugly over both your mouth and nose. The mask protects you and protects others around you from aerosols you might produce while unknowingly shedding the COVID-19 virus. 

Learn more information about the COVID-19 vaccines and booster shots.

With omicron so transmissible, some have assumed everyone will get the virus eventually and questioned whether safety precautions are worth it. What are the risks of that approach?

Getting infected with omicron is not inevitable. Over time, most of us will be exposed to the COVID-19 virus if we haven't already. You really want to be vaccinated and boosted when you encounter this virus. It could still protect you from an infection, and it will protect you from severe disease. Going out in public right now with no regard to being exposed to the virus is not a good idea. 

Secondly, we know that infections are not always mild. Some people need to be hospitalized, some get severely ill, and some have symptoms that persist for long periods of time. This is called “long COVID” or “long-haul COVID.” You really want to avoid that if possible. We know that the vaccine reduces the probability of long COVID symptoms by over 50%. 

Finally, early in the pandemic, we talked about crushing the curve. We wanted to avoid these very high peaks of infections, because those high numbers have the potential to overwhelm hospitals. That’s still important today, because even if only a half a percent of the people who are infected require hospitalization, if you have 300% or 400% more cases, that's a lot of people who need hospitalization.

Should people who previously had COVID-19 get the COVID-19 vaccine and a booster shot, if eligible?

Yes. With your immune system, we know that repeated exposure through multiple doses of vaccine (or an infection followed by the vaccine) increases the levels of antibodies in your blood, as well as the quality of those antibodies—they can bind to the virus better. The vaccine bolsters the antibody response even after natural infection. 

Antibody levels decrease over time both after natural infection and following the first two doses of vaccine, so you are not immune to reinfection forever. Our current recommendation is to get the booster about five months after your final dose of the vaccine.

How likely is reinfection after you’ve had COVID-19 and what factors are involved?

The large studies that were done early in the pandemic showed that after a documented COVID-19 infection, for about the next six months or so, those individuals were up to tenfold less likely to get infected. In some of the studies, even more than that, compared to someone who hadn't been infected. 

We do believe some of that protection remains. However, the omicron variant is much more transmissible than previous variants. The omicron variant can evade some of the immunity that is built up by previous infection. Omicron does seem more likely to cause a repeat infection among those who were infected with a previous variant of the virus. 

Your risk of infection from COVID-19 also depends on how well you are following the safety practices, such as getting vaccinated, wearing masks, social distancing, and trying to reduce exposure to the virus. When there is a lot of COVID-19 circulating in your community, you are more likely to be exposed to the virus, especially if you’re not following those safety practices. 

With all the variables, defining the specific risk of reinfection is difficult, but we know that six months after the infection, the risk of reinfection increases. So it is still important to get vaccinated, even if it's right after you've had an infection. If you haven't been vaccinated, you shouldn't depend on the infection-induced immunity alone. 

What does the latest research say about the likelihood of long-COVID based on your vaccination status?

The COVID-19 vaccines reduce the incidence of symptoms that last over 28 days, like brain fog or severe fatigue. For those who have been vaccinated but have a breakthrough infection, the incidence is reduced by 50%. 

Remember, vaccines aren't perfect. Your immune system has to recognize the vaccine and make antibodies. Some people who are immunocompromised don't make a good immune response to the vaccines. Sometimes, natural genetics or other factors prevent a person from having a good immune response. But overall, the vaccines reduce the likelihood of long-COVID symptoms.

Lots of myths have circulated about treatments for people who have COVID-19. What treatments have been shown to be the most effective for patients hospitalized with COVID-19?

We've learned a lot about treatment of patients who get severe COVID-19 and need to be hospitalized. Often, when a patient with COVID-19 needs to be admitted to the intensive care unit, they are sick because of the interplay between the virus and their immune system. Medications that target other parts of the immune system that could cause the disease to get worse are used regularly, and they’ve really helped reduce the death rate from COVID-19. 

On the outpatient side, monoclonal antibodies have been effective against COVID-19. This treatment is for people who are at higher risk of complications from the virus. One of the monoclonal antibody treatments we have access to is still effective against the omicron variant. 

There are also some oral antiviral therapies that can be used within three to five days of your symptoms beginning. They are in limited supply now, but these therapies are highly effective at preventing hospitalization and severe outcomes. 

These treatments are all very promising, but prevention is always much better than treatment.

What are the most important things Iowans can do to help end this pandemic?

Get vaccinated if you haven't already been vaccinated, and get your booster shot, if you're eligible. 

Wear a mask when you’re outside of your household in public. Wear a medical-grade mask instead of a cloth mask by itself, or wear a cloth mask over the medical-grade mask to get a better fit. 

If the KN95 masks are more comfortable for you, those are also highly effective.  

If you have family members who have a compromised immune system, they need to be protected as best as we can protect them. Do that by surrounding them with vaccinated people. It may mean going to the grocery store for them, so they don't have to go out in public.  

Right now, while infection rates are high, don’t hold or attend big gatherings. It’s the right time to be careful and to be more intentional about your safety practices, until this surge with omicron subsides.