The Centers for Disease Control and Prevention (CDC) decided to limit its tracking of people who contracted the Wuhan coronavirus (COVID-19) despite vaccination. It recorded more than 9,000 breakthrough COVID-19 cases – a tiny percentage of the total number immunized. The CDC’s move drew concern from scientists who remarked that it only made investigations on the breakthrough infections more difficult.
According to the public health agency, it would only report “patients with COVID-19 vaccine breakthrough infection that were hospitalized or died” effective May 14. It cited a need to “maximize the quality of the data collected” for the decision. The CDC nevertheless acknowledged that breakthrough cases are to be expected as no vaccine is 100 percent effective in preventing illness.
CDC official Dr. Thomas Clark elaborated that it shifted its reporting strategy due to “few worrying patterns” in their collected data. He continued that the agency’s current data suggested a focus on more severe cases. “I don’t think we’re missing out on this data. It’s just sort of a package of how we’re looking at these questions [regarding breakthrough infections],” Clark said in an interview.
However, the public health agency noted that the official numbers are probably an undercount. This is because its Vaccine Adverse Event Reporting System is passive and relies on voluntary reporting from state health departments. These departments may be reporting incomplete figures, the CDC added.
Clark commented that the agency has planned other vaccine studies to look at the severity of COVID-19 cases in both vaccinated and unvaccinated people. It also planned to look at the frequency of infections caused by circulating Wuhan coronavirus variants in both groups. The CDC has partnered with a network of health centers for this particular purpose.
But some scientists have argued in favor of tracking and sequencing all breakthrough infections. They claimed that it helps figure out who may be more at risk, when vaccine protection decreases and if new variants bypass vaccine-induced protection. Scripps Research Translational Institute Founder and Director Dr. Eric Topol said: “We shouldn’t be narrowing the focus, [Instead,] we should be broadening and [developing] a systematic plan.”
Washington University in St. Louis Associate Vice Chancellor Michael Kinch said information on breakthrough COVID-19 cases should be recorded as much as possible. He added that cases that do not progress to hospitalization should also be tracked nevertheless as some patients could eventually go down that path. “It’s essential that we stay on top of this. If we let our guard down, we will pay the price,” Kinch said.