I recently discussed a new CDC study that stated that the COVID-19 vaccines provided better protection than a previous infection. Unfortunately, I buried the lede – COVID-19 vaccines are better than a prior COVID-19 infection in keeping you out of the hospital.
Not to be repeatedly repetitive, but I am going to re-review that paper in light of the lede – in other words, the anti-vaxxers keep ranting on about a prior COVID-19 infection. I don't think it means what they think it means.
Prior COVID-19 infection – the paper
On 29 October 2021, a paper was published in the Morbidity and Mortality Weekly Report by Centers for Disease Control and Protection (CDC) scientists. They examined more than 7,000 people across 9 states who were hospitalized with COVID-19.
The patients were in the VISION Network, which includes Columbia University Irving Medical Center (New York), HealthPartners (Minnesota and Wisconsin), Intermountain Healthcare (Utah), Kaiser Permanente Northern California (California), Kaiser Permanente Northwest (Oregon and Washington), Regenstrief Institute (Indiana), and University of Colorado (Colorado). The VISION Network, which includes 187 hospitals, is a database that allows researchers to examine various aspects of COVID-19 and vaccines.
The researchers examined hospitalizations in adults with COVID-19 illness and compared the odds of receiving a positive SARS-CoV-2 test result between unvaccinated patients with a previous SARS-CoV-2 infection occurring 90–179 days before COVID-19 illness hospitalization, and patients who were fully vaccinated with an mRNA COVID-19 vaccine (either Moderna or Pfizer) 90–179 days before hospitalization with no previous documented SARS-CoV-2 infection.
Essentially, they found that unvaccinated, previously-infected adults were 5.49 times more likely to contract laboratory-confirmed COVID-19 compared to fully-vaccinated recipients of an mRNA COVID-19 vaccine with no previously documented infection.
The researchers concluded that:
These findings suggest that among hospitalized adults with COVID-19–like illness whose previous infection or vaccination occurred 90–179 days earlier, vaccine-induced immunity was more protective than infection-induced immunity against laboratory-confirmed COVID-19. All eligible persons should be vaccinated against COVID-19 as soon as possible, including unvaccinated persons previously infected with SARS-CoV-2.
Let's look at it in another way. Among more than 7,000 individuals who were hospitalized for COVID-like symptoms, 8.7% of unvaccinated adults with a prior infection at least 3 months before testing positive for SARS-CoV-2 again, as compared to 5.1% of the fully vaccinated patients without a prior history of infection, for an adjusted odds ratio (OR) of 5.49 (95% CI 2.75-10.99) after factoring in local positivity rates, age, and numerous other factors.
There is one more thing I wish this study showed – a comparison of the risk of hospitalization for those who were previously infected AND were fully vaccinated compared to an infection-only cohort and a vaccine-only cohort.
As I wrote before, this study strongly demonstrates that the COVID-19 vaccine can provide a higher, more robust, and more consistent level of immunity than "natural" illness. And the vaccine can protect people from hospitalization for COVID-19 than infection alone for at least 6 months.
I doubt that this will convince the committed anti-vaxxer, who want us to believe that anything from horse dewormer to risking death from the disease itself is better than the vaccines. But the scientific facts contradict that – vaccines keep you out of the hospital while contracting COVID-19 does not.
Get the vaccine.