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Share of breakthrough coronavirus infections increasing as omicron spreads in Missouri


Missouri is seeing a larger share of fully vaccinated or previously infected people getting the coronavirus amid a surge powered by the more transmissible omicron variant.

The share of breakthrough infections in Missouri has hit pandemic highs over the last two weeks. Those cases made up nearly 22% of new infections last week and 46% of new cases the week before, according to the Missouri Department of Health and Senior Services. Almost 8% of cases so far in Jan. are of people previously infected with the virus.

Dr. Robin Blount with Boone Health says, "although we are seeing breakthroughs with those who are vaccinated, boosted or not, they still aren't the ones ending up in the hospital, you know sick for days, weeks or even dying."

Health experts believe the new omicron variant of the coronavirus is better able to evade vaccine protection but that vaccines remain effective against the virus causing severe illness and death. And they're emphasizing the importance of third shots to get maximum protection.

Marc Johnson, Professor at the University of Missouri School of Medicine, says, "Omicron infections are less severe but ,from the best data we have that is predominantly because the people that it is infecting have immunity."

“However, what is the somewhat encouraging news is that the protection against hospitalization and severe disease, although it goes down to around 70% from around 93% — when you get boosted, it brings it back up to the level of pretty good protection,” Dr. Anthony Fauci, the nation's top infectious disease expert, said Sunday on CNN.

Total coronavirus cases and breakthrough infections in Missouri

Missouri health officials continue to promote boosters as effective protection against the virus. Nearly 90% of Missouri's COVID-19 deaths were in people not fully vaccinated.

"Booster doses are incredibly important to increase your level of immunity as new variants circulate," the state health department posted on social media last week. "Research shows that COVID-19 vaccines continue to be highly effective at preventing severe illness and death."

Reinfection occurs when someone tests positive for COVID-19 via PCR or antigen test, recovers, and then 90 days or later tests positive again.

The state health department reports 17,443 people have been previously infected with COVID-19 and been reinfected out of nearly 850,000 cases throughout the pandemic. Out of more than 3.3 million fully vaccinated people in Missouri, the state has logged 121,117 breakthrough cases of COVID-19.

A breakthrough infection is a COVID-19 case that occurs in someone who is fully vaccinated, which means 14 days have passed since getting a second shot of the Pfizer or Moderna vaccines or a single shot of Johnson & Johnson.

University of Missouri Health Care reported 83 people in its hospitals Monday morning with COVID-19, with 20 of them vaccinated and 62 unvaccinated. Of MU Health's 21 intensive care COVID-19 patients, 19 are not fully vaccinated.

MU Health Care had 16 patients on ventilators, one being vaccinated and 15 being unvaccinated.

Vaccinations statewide have been on a downward trajectory since the start of Dec., with Missouri's rate of full vaccination stalled at about 54%. Most of the shots given since that time have been boosters.

Erika McGuire



    1. Well I have a local hospital witch has cancelled all elective procedures, has inadequate staff to handle even urgent and emergent issues and multiple patients that are actively dying right now because of your “Bad Cold” . you need to try, at the very least, to learn something, ANYTHING, about this subject which you opine upon frequently without even the remotest idea about the subject matter.

    1. Lisa I don’t think you know what “effective” means, Well I don’t anyway, and I live and work in this arena! Appropriate terms include specificity, sensitivity, and positive or negative predictive value. you can also use the term accuracy but I have never heard the term effective applied to a test of this type. It sounds to me, much like Alice, that you have absolutely no idea what you are talking about.

      1. Maybe you should stick to anesthesiology Lisa. Clearly you are out of your depth here. FYI, The PCR test was found to be 87% sensitive and 97% specific, with a positive predictive value of 0.98 and a negative predictive value of 0.80. PPV is related to prevalence, which is currently very high… but then you weren’t that great at stats in nursing school either !

      2. CDC 12/29/2021: “people can remain PCR positive for up to 12 weeks after infection and long after they are transmissible and infectious.” False positives for for as many as 12 weeks. Which can also be generated by “adjusting” cycles to produce the desired results. You argue semantics.

        1. So lets start by agreeing that someone who has absolutely no idea about epidemiology, virology or medicine in general, would likely think that the difference between using the word “effective” or using the word “accurate” may be “semantics” … that being said those people know nothing about medicine, virology or epidemiology. (they should probably not be opining on the said subjects on a social media platform and making a public fool of themselves.)

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