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The beginning of the end of the coronavirus?

University of Virginia immunologist and COVID-19 researcher Dr. William Petri continues to answer reader questions about COVID-19. Send your questions to Lynne Anderson at, and she will forward them to Dr. Petri.

I am so confused and exhausted from COVID-19. I thought the vaccines were going to protect us, but then along came omicron. Did the virus outsmart the vaccines?

Omicron is the beginning of the end. By mid- to late February, we will see the omicron wave subside in Virginia, as it already has in the United Kingdom. As it recedes, our world will be a better place. Two years ago, none of us were immune to COVID-19; by the spring, almost all of us will be. With this unprecedented high level of immunity, we can all look forward to a summer as summers past, without social isolation, school disruption, travel restrictions, lockdowns, masks, or social distancing. I think July 4th will be Independence Day in more than one way!

The reason for this simply is that omicron will have infected half of the world’s population by late spring. Add onto that immunity to COVID-19 from vaccination, and the U.S. will have the highest level of immunity ever. This will change COVID-19 to an endemic infection, with winter epidemics such as we have with influenza. When COVID-19 epidemics arise in the future, we will be in a much better position to protect ourselves through the combination of vaccination, pills to treat it such as Paxlovid and Molupiravir, and during epidemics, reinstitution of wearing masks and social distancing, especially for the elderly and most vulnerable segments of our population.

And yes, you are right that omicron outsmarted the vaccines, but only somewhat. The boosted vaccines are still reducing the risk of hospitalization and death 10-fold which is amazing, saving lives and keeping our hospitals from being even more overwhelmed. But clearly the vaccines are less effective at preventing a mild or asymptomatic omicron infection, which I saw in my own family over the holidays when three of our five children had sore throats from omicron! Expect better vaccines targeted to omicron soon.

My cousin in New York is getting a fourth COVID-19 shot. She said she can get one four months after her booster. Can we really get those fourth shots now? And where should we go to get one?

You really can’t get a fourth shot now, but I think you can be reassured that having been boosted, you are already quite well protected from severe COVID-19. A second booster (i.e., fourth shot) of the vaccine is being given to high-risk individuals in Israel, but not in the U.S. The argument to give a second booster stems from data from the United Kingdom, where the Pfizer vaccine booster waned in effectiveness in preventing mild COVID-19 after 4 months. The argument against giving a second booster is that the benefit would be incremental, i.e., just adding protection against mild COVID-19. Thank goodness for the vaccines, which have saved millions of lives!

The U.S. had a lower vaccination rate than it expected. Do the large numbers of unvaccinated people contribute to the virus’s ability to mutate and thus still move among us?

Unfortunately, it only takes one infected person for a new variant to arise. We saw this with the alpha variant from Kent England, and again with omicron from southern Africa. By fingerprinting or sequencing omicron, what was discovered was that it had emerged from the original SARS-CoV-2 virus from 2020 and not from the variants that had since arisen such as alpha, beta, gamma or delta. What this means is that one person, likely with a weakened immune system, was chronically infected for more than a year, during which time the virus mutated more and more until it became the omicron variant. So higher levels of vaccination are desirable frankly because it saves lives but are not going to entirely prevent new variants from arising.

Generally speaking, people are not getting as sick from omicron as they did from the virus that first spread or from delta. Those viruses both caused significant lung problems, and omicron does not. Are we even dealing with the same disease when we talk about an omicron-induced infection as we were with the one from two years ago?

You are correct that omicron is causing less severe illness. Best estimates, however, are that because of the ten-fold higher number of infections than we saw with delta, hospitalization of patients with COVID-19 pneumonia are at the highest ever, at over 150,000 in the US. At the University of Virginia Hospital Wednesday, there were 31 patients in the ICU and a total of 105 total admitted with acute COVID-19, which is tragically higher than the prior record back in January of 2021. But infections without symptoms may be as high as 90% with omicron as compared to only 40% with delta. My take on this is that omicron is not to be trifled with, but that the net result of having so many mostly mild infections will be the end of the pandemic.

If I get omicron, will I have immunity from COVID-19? I have heard of some people wanting to get exposed to this variant in hopes they might be immune.

Omicron infection does provide some degree of immunity to reinfection, but not lifelong as does, for example, measles. Immunity to COVID-19 decreases over time both for those who have recovered from infection as well as those who have been vaccinated. And while too early to know for omicron, for earlier variants the vaccine gave added protection to those who had recovered from COVID-19. Where the current vaccines are not working well is in preventing asymptomatic or mild omicron infections; they are still 90-plus percent effective at preventing death. I hope no one intentionally exposes themselves to omicron to gain even this partial immunity, as vaccination is far safer!

How long does immunity from COVID-19 generally last?

Months to years if we are talking about immunity from severe COVID-19. I anticipate that some frequency of vaccine boosting will be required to maintain that degree of immunity, just as we do by getting our annual flu booster, or once every 10 years for the tetanus shot. And like flu, the boosters will be adjusted to better protect against whatever the current variant is.

I’m a 62-year-old grandmother with a 4-year-old granddaughter who just tested positive. My husband and I tested positive two weeks ago. Her mother – my daughter – is two days away from a scheduled C-section. She and her husband are vaccinated. My husband and I are planning to fly to their hometown to stay to help with the new baby. Neither of us is vaccinated. What precautions should I take for myself, my daughter and her family?

I am so glad that you and your husband only had mild disease when you caught omicron! This is one of those “count your blessings” type things, since being a senior like me, yours could have been much worse. And how wonderful that you are now recovered and able to help with your soon-to-be-born new grandbaby! It is not too late to get vaccinated, which will improve on the protection that you now have from omicron. Wear an N-95 or KN-95 mask in the airport and on the plane and get tested (the in-home rapid tests are fine) the day before to be sure that you don’t inadvertently bring the infection with you. I imagine your granddaughter is going to so enjoy the extra attention you and your husband can give her now that her parents’ attention is divided!

If one has had one variant of COVID-19, how likely is it that they might get another variant? Just as getting influenza A doesn’t protect from influenza B.

I am continually impressed by the sophisticated thought-provoking questions that I get for this column, including yours! Variants of the COVID-19 virus are much more like one another than influenza A is to influenza B (which are about as closely related to one another as astrology is to astronomy!). The similarity between older variants and omicron is helping us, with a prior COVID infection providing at least 20% immunity to omicron. Therefore, virologists and epidemiologists are optimistic that omicron is going to usher in the end of pandemic spread of COVID-19. The caveat is that we will need to maintain the high level of immunity present this spring-summer, through some frequency of vaccine boosting.


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