Like data released by other health departments, the analysis from DSHS purports that the number of COVID-19 cases and fatalities is significantly lower among vaccinated individuals than those who have not received a vaccination against the virus.
But the estimates are still sharply different from those of their federal counterpart, the Centers for Disease Control and Prevention (CDC), which has released similar data.
DSHS says unvaccinated individuals are 13 times more likely to become infected with COVID-19 than those who are fully vaccinated; the CDC says six times more likely.
DSHS says unvaccinated people were 20 times more likely to “experience COVID-19-associated death;” CDC says 11 times more likely.
Asked about the DSHS survey with estimates twice as high as the CDC’s report, the DSHS director of media relations, Chris Van Deusen, told The Texan, “As you’d expect, there will be differences depending on the time period being looked at and the state of the pandemic in a particular time and place.”
The dates of the two reports cover different sections of the recent wave of the Delta variant cases that swept across Texas and the country. While the CDC looked at the month of August as cases were rising, the DSHS data looks at the bulk of September as cases declined.
And while Texas’ data was limited to the Lone Star State, the CDC says it used data from 16 health departments in states with vastly different COVID-19 policies such as New York and Massachusetts, but also a host of southern states that have had trends and policies similar to Texas, such as Florida, Georgia, Arkansas, and Louisiana.
Other factors that Van Deusen said could contribute to the difference between the CDC and DSHS reports are variations from “jurisdiction to jurisdiction” on the overall course of the pandemic, “the proportion of people taking non-pharmaceutical interventions, including masking and distancing,” vaccine coverage, and methods in collecting and analyzing COVID-19 data.
The DSHS survey acknowledges several limitations to the report, including potential “lags in reporting” that “may have led to some information being incomplete at the time of analysis,” as well as that “variable linkage of case, vaccination, and mortality data might have resulted in misclassifications that could influence [incidence rate ratio] estimates.”
Another limitation noted is that, “Immunization data for COVID-19 are dependent on clinician report of status to ImmTrac2,” the immunization registry in Texas.
“As a condition of being a COVID-19 vaccine provider, each provider is required to report all doses administered into the immunization registry within 24 hours. While we cannot guarantee that they all meet that requirement every day, the data cutoff for the study (Oct. 1), means that nearly all doses given would be in the registry by the time the data was pulled,” said Van Deusen.
He also noted that ImmTrac “does not contain information about people not vaccinated,” so where no vaccination information could be matched to the details of a case or death, the individual was assumed to be unvaccinated.
Besides providing some crude case and fatality rate graphs in the survey, DSHS has not provided any regularly updated, date-specific data breaking down vaccinated and unvaccinated comparisons like the department has done for case, hospitalization, and fatality numbers over the past year and a half with its other COVID-19 data.
“We haven’t done this analysis on a daily basis; I’m not sure what the utility of that would be,” said Van Deusen.
The survey also does not look on hospitalizations — Van Deusen says DSHS does not have “similar comprehensive data” on that metric for vaccinated vs. unvaccinated patients — nor does it examine the potential waning efficiency of vaccines, the variable efficiency for different vaccine brands, the likelihood of reinfections for unvaccinated people, or the likelihood of transmission between vaccinated and unvaccinated people.
Based on the CDC’s report, the single-dose Janssen vaccine (Johnson and Johnson) has seen the most breakthrough cases, followed by the Pfizer and Moderna vaccines.
At the peak of cases on the CDC’s chart, August 21, the agency reports that 737 out of every 100,00 unvaccinated individuals tested positive for COVID-19, while that number was 172 for the Janssen vaccine, 136 for the Pfizer vaccine, and 86 for the Moderna vaccine.
Though Moderna has seen the greatest reported success at staving off the virus, it has also faced more scrutiny out of concern that it could be linked to myocarditis, especially for young men.
A study from France reportedly showed that among men between the ages of 12 and 29, there were 13.3 cases of myocarditis per 100,000 people who received the Moderna vaccine — far higher than the 0.71 deaths per 100,000 people that the CDC shows at the height of August’s wave for both genders of the same age range.