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COVID-19 cases in New Mexico have ticked up 121% in about a month and plenty of those are breakthrough cases, according to weekly epidemiology reports.
But we don’t know how many.
About a month ago the state Department of Health quietly removed from its weekly epidemiology reports data that compared the most recent four weeks of cases, hospitalizations and deaths among unvaccinated, vaccinated and vaccinated and boosted people. The removal of the breakthrough case data came as a greater share of people who were getting sick with COVID-19 had been vaccinated.
Dr. Christine Ross, the state epidemiologist, said the decision was made to pull the data from its public reports because it wasn’t a clear indicator of vaccine effectiveness. State health officials have long tried to increase vaccination rates, even going so far as to offer prizes and other incentives to get the shots.
“The pandemic itself has become more complicated over time, there are more reinfections, there’s different adjustments that would need to be made to this type of analysis for it to continue accurately displaying risk or vaccine effectiveness,” she said in an interview.
As a result of removing the data, it’s unclear how many of the recent cases, hospitalizations and deaths are breakthrough cases.
Every week, the state Health Department releases several epidemiology reports that show COVID-19 trends throughout the state. Some of the reports show the weekly case counts and hospitalizations. There’s also a vaccination report that compares outcomes of individuals based on their vaccination status. There is a cumulative case page, and there used to be a page showing data from the last four weeks. Originally, the four-week data showed almost all serious cases were among the unvaccinated.
For example, in the report dated Feb. 7, unvaccinated individuals accounted for 51% of new cases, 74% of hospitalizations and 88.9% of the deaths in the previous four weeks.
The report showed an unvaccinated person was eight times more likely to die of COVID-19 during the previous four weeks than a person who was vaccinated, and a whopping 29 times more likely to die than someone who had the vaccine and a booster.
But as the omicron variant started to spread, vaccinated and boosted individuals began to make up a greater share of serious cases.
In the report dated April 18, unvaccinated people accounted for 39.1% of cases, 55.7% of hospitalizations and 45.5% of the deaths in the previous four weeks.
The state stopped publishing four-week vaccination reports the next week.
The data in that report showed that during the previous four weeks, there were more cases, hospitalizations and deaths among those who had a booster than people who had only received their primary vaccine series.
An unvaccinated person was twice as likely to be hospitalized and 1.7 times as likely to die than a person who was vaccinated and had a booster. An unvaccinated person was three times as likely to be hospitalized and 1.9 times as likely to die than a person who had been vaccinated but not boosted.
There are plenty of explanations for why that might be the case, Ross said. For example, an older adult with multiple underlying conditions is probably more likely to get the booster shot than an otherwise healthy adult who was vaccinated.
Also, the data doesn’t take into account how long people were removed from their last vaccine.
“Everybody isn’t on the same playing field,” Ross said. “You’re probably more likely to take the time out of your day to seek out a booster if you’re in fact a higher risk individual. So you’re probably older, you may have multiple comorbidities, and that puts you at higher risk for severe outcomes.”
Dr. Paul Fenimore, a scientist at Los Alamos National Laboratory who specializes in predictive modeling, reviewed the state’s vaccination reports. He said multiple factors have turned raw vaccination data, a once useful gauge, into a “complex mess.”
The vaccines’ protectiveness has waned over time as the virus evolved and new variants emerged. Vaccinated people have had a mixture of one, two, three or four shots. Additionally, a much larger percentage of the population has now had COVID-19, which changes their immunity.
And crucially, the advent of at-home testing means that the many people who get COVID-19 and don’t need any care never show up in the new case counts.
“We’re simply diagnosing more sick people who are seriously sick, and we’re missing more of the people with mild illness,” he said. “Those imperfections have the character of being a bias, so that you see sort of the bad side of the coin.”
Those at-home test cases represent a case that would be evidence showing the vaccine is effective, because the person was vaccinated and didn’t get seriously sick, could throw off the existing raw data, he said.
“The intent of showing that data is to tell people what the vaccine efficacy is, and when you know that there’s a bias linked to that. You can be confident that the vaccine efficacy numbers are pessimistic,” he said. “You’re sitting there always looking at the people who show up in the hospital. And those are, by definition, people who feel lousy.”
Vaccine still effective
The four-week vaccination reports – even the last one the state released – still showed the vaccine was effective.
Even though unvaccinated people accounted for just 45.5% of deaths in that four-week period, they accounted for a greater share of deaths. Only 20% of adults are unvaccinated in the state, according to the Health Department’s website.
“So we know that with omicron, and with waning immunity, that protection against an infection has changed, and has decreased over time,” Ross said. “So we’ve seen, we’ve seen more breakthrough cases. But these vaccines still remain highly effective at preventing severe outcomes, hospitalizations and deaths.”
Ross said multiple studies and clinical trials show the vaccines are effective at preventing serious diseases and death.
“All I can say is, you’re going to have to trust that our goal is to present information that makes sense. And that is useful,” she said. “You have to be willing to look at all of the different methodologies that evaluate vaccine effectiveness. If you stick on this one methodology, which is using – it’s a very simple type of analysis using observational data – I think you’re kind of missing the boat.”
Ross said that New Mexico was one of only a handful of jurisdictions in the country that was providing the four-week data in the first place. She said the CDC has broken the country down into 67 jurisdictions, and New Mexico was one of only about 25 that were regularly producing surveillance data, which is how the state produced the four-week vaccination report.
She said all of those jurisdictions have decided to not publish that information anymore.
Jodi McGinnis Porter, a spokeswoman for the Department of Health, said that officials in all 25 of those jurisdictions are grappling with how to publish the data in a manner that accounts for issues like comorbidities, reinfection status, time since a person’s vaccination, age and access to care.
“DOH is working with other jurisdictions and CDC to develop appropriate new methods to improve our analysis of the surveillance data,” she said in a statement. “Our aim is accuracy and transparency, and we are working with others to produce ‘actionable epidemiological data’ with reports meant to aid, not obscure, understanding.”
New Mexico reported 636 new COVID-19 cases on Friday and 11 more deaths, pushing the statewide toll to 7,675 since the start of the pandemic.
There were 75 people hospitalized with COVID-19, including 10 on ventilators.
The state is seeing an upswing in cases.
In the weekly epidemiology report dated May 16, New Mexico reported 2,479 new cases in the previous week, which marked a 41% increase from the week before when there were 1,764 new cases. The week before April 25, there were 1,117 new cases.
There were 52 people hospitalized with COVID-19 in the previous week, up from 33 the week before.
It’s not known how many of the recent cases, hospitalizations and deaths were breakthrough cases.