CDC should track more COVID-19 breakthrough infections to get ahead of the pandemic, experts warn

The Centers for Disease Control and Prevention (CDC) says the best way to prevent infection and slow the spread of COVID-19 is to get vaccinatedbut the total number of breakthrough cases is unknown because the agency only monitors the most severe on a monthly basis, according to Medpage Today.

After May 1, 2021, the CDC streamlined from reporting all breakthrough COVID-19 infections to only monitoring the most severe cases, with the agency acknowledging the total number of cases are under underrepresented because of the asymptomatic patients or mild cases who do not seek care or testing.

Dr. Devang Sanghavi, medical director of the medical intensivist unit at Mayo Clinic, told the American Medical Association (AMA) that a breakthrough COVID-19 infection is defined as the detection of COVID-19 viral RNA or antigen in a respiratory specimen collected 14 days after receiving the second dose of Moderna or Pfizer mRNA vaccines or two weeks after the first dose of Johnson & Johnson COVID-19 vaccine.

Coronavirus.  Courtesy of the CDC

Coronavirus. Courtesy of the CDC

The CDC transitioned to focus on the breakthrough cases of the highest clinical and public health significance “because many breakthrough infections among fully vaccinated people will not develop into serious illness compared to those who are unvaccinated and get COVID-19,” the agency noted.

“One of the strengths of this system is collecting data on severe cases of vaccine breakthrough COVID-19 since it is likely that most of these types of vaccine breakthrough cases seek medical care and are diagnosed and reported as a COVID-19 case,” the agency said.

Hospital workers process COVID-19 tests at a hospital in Aiea, Hawaii, Wednesday, Sept.  15, 2021. (AP Photo / Caleb Jones)

Hospital workers process COVID-19 tests at a hospital in Aiea, Hawaii, Wednesday, Sept. 15, 2021. (AP Photo / Caleb Jones)

Approximately 10% of people who develop breakthrough infections, however, still require hospitalization, Sanghavi told the AMA. “One percent to 2% of those hospitalized from breakthrough infections may still die, unfortunately. So, it’s still a concern,” he added.


A CDC spokesperson told Fox News the agency monitors rates of COVID-19 breakthrough cases and their associated hospitalization and deaths on a monthly basis, not continuously, because, “These data are reported based on when the patient was tested, not the date they died . ”

“Deaths usually occur up to 30 days after diagnosis. This is why CDC allows at least 4 weeks of lag time to link case surveillance data to Immunization Information System(IIS) and vital records data up to a month after the diagnosis. ”

Dr. Eric Topol, professor and executive vice president of Scripps Research and founder and director of Scripps Research Translational Institute, however, told Fox News, “The CDC vaccination breakthrough data reporting has been grossly inadequate.”

Healthcare worker administers COVID-19 test.

Healthcare worker administers COVID-19 test.

When the pandemic first started, the level of protection from the vaccines could be interpreted by monitoring breakthrough infections between the unvaccinated and those who were vaccinated, “… but now it is more a comparison of vaccinated versus previously infected [with COVID-19]”said David Dowdy, MD, PhD, an epidemiologist and associate professor at the Johns Hopkins Bloomberg School of Public Health in Baltimore.

Dowdy told Fox News, “Now that the vast majority of the unvaccinated population has been infected, measurement of ‘breakthrough’ infections is more difficult to interpret.”


COVID-19 infections among vaccinated people were not common with the delta variant, but because the omicron variant is more transmissible, “It is not uncommon to see breakthrough infections,” added Sanghaviwho also noted breakthrough infections occur among vaccinated people because their immunity wanes over hour.

He said because the vaccines were created for a different strain than the omicron variant, “… the efficacy of the vaccine itself may not be as good for omicron as compared to say delta as compared to alpha [variant]which was what it was originally designed for. ”

Saad Omer, MPH, PhD, the director of the Yale Institute for Global Health, told NPR last year that tracking non-severe breakthrough infections is also important.

“In this pandemic, unfortunately, we have been chasing the outbreak. And the way to control an outbreak is to get ahead of it. And one way to get ahead of it is to detect these early signals and make sure you are testing not just severe cases that take time to sort of get to the hospital“he said.


“It’s the unknown unknowns that get us.”

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