RALEIGH, NC (WNCN) – Thousands of new cases of COVID-19 are pouring into North Carolina each week during this recent surge.
But what we don’t know is how many of these are breakthroughs.
That’s because the state Health Department’s weekly count has quietly disappeared – after months of being included in the weekly respiratory virus surveillance report.
It could be a big problem — when it comes to data, less isn’t often actually more — but doctors say the agency’s rationale for the decision to remove these updates makes sense.
“As of this writing, several years into the pandemic and over a year into vaccinations, it’s not that important to us,” said Dr. Erica Pettigrew, general practitioner and assistant professor at the University of North Carolina School of Medicine.
Our state isn’t the only one to stop releasing this count: New Mexico, for example, also removed its post-vaccination case data from its public reports.
The latest update from NCDHHS came in the report published on April 21st and covered the period from New Year’s Day 2021 to April 9th this year.
A total of more than 540,000 cases were counted after vaccination, of which almost 434,000 were in vaccinated people and a further 106,000 in booster vaccinations.
In a statement, NCDHHS called the breakthrough totals “difficult to interpret,” but says it continues to track them even though that total is no longer released weekly.
“Recent trends in reported case rates after vaccination and booster vaccination are difficult to interpret given the differences in time since vaccination and the high rate of recent infections, particularly in the unvaccinated population,” NCDHHS said. “The bare number of cases after vaccination is also difficult to interpret for similar reasons.”
A significant complicating factor is that people have different levels of protection depending on the timing of the shot or shots they received. Someone who only received the basic series of vaccines last spring has a much lower level of protection than a person who was double-vaccinated.
“There are too many of these variables to fit into a nice clean number,” Pettigrew said.
And because so many people are testing at home — and those numbers are rarely reported to health officials, and rarely factored into those case counts — the total is certainly a massive undercount.
Nonetheless, NCDHHS still considers caseload to be one of the seven key actions it is pursuing.
So why not break it down by vaccination status?
dr Thomas Holland, an infectious disease specialist at Duke University School of Medicine, says it’s not that simple.
“I think it’s still informative just to look at the total number of cases, but it’s become more difficult to relate it to some sort of vaccinated versus unvaccinated rate,” he said.
Breakthroughs were such a big deal early in the pandemic because there are two types of immunity: sterilizing, meaning a vaccinated person would never get the disease, and functional, meaning a vaccinated person can get the disease but is largely protected from the most severe cases of it. Public health experts were unsure of what type the vaccines would produce.
“So it was really important to track it when so many people started getting vaccinated because it was a question we didn’t have an answer to yet,” Pettigrew said.
“If someone has a breakthrough infection we expect it, we know it happens, we’re also very confident that the hospitalization and death rates are much lower for those who are vaccinated,” she added.
“So we still have to focus on getting people vaccinated and getting them their boosters. But as a metric, tracking breakthrough infections over time is less meaningful for us.”
dr Pia MacDonald, an epidemiologist at RTI International, agrees with the agency’s rationale but says breakthroughs will still be an important avenue – but the best way to do that is in the clinical setting, she said.
And it becomes even more important to monitor them as more variants develop.
“With any new variant, it’s important to understand who gets infected, what changes in the effectiveness of the vaccine, what changes in how much a previous infection protects us,” she said. “So in terms of understanding the epidemiology, this remains an important indicator for us. But where we can see it, the clinical setting is an efficient way to do it.”
CBS 17 Joedy McCreary has been tracking COVID-19 numbers since March 2020, compiling data from federal, state and local sources to provide a clear snapshot of what the coronavirus situation is now and what it could be in the future.
https://www.cbs17.com/community/health/coronavirus/what-happened-to-ncs-running-count-of-breakthrough-covid-cases/ What Happened to NC’s Running tally of Groundbreaking COVID Cases?