CDC Changes Rules for Counting Breakthrough Cases, as More Fully Vaccinated People Test Positive

The Centers for Disease Control and Prevention will report only those breakthrough cases resulting in hospitalization or death. The agency also lowered the testing threshold, but only for the fully vaccinated.

As more reports surface of breakthrough COVID cases, in and outside the U.S., the Centers for Disease Control and Prevention (CDC) today said it will change how breakthrough cases are reported, effective May 14.

According to a statement on the CDC’s website, the agency said to help “maximize the quality of the data collected on cases of greatest clinical and public health importance” it will stop reporting weekly COVID breakthrough infections unless they result in hospitalization or death.

The news followed another change, announced late last month, in how PCR tests should be administered to the fully vaccinated.

Both changes will result in lower overall numbers of reports of breakthrough cases in the U.S.

breakthrough case is recorded if a person tests positive for SARS-Cov-2 two weeks after receiving the single-dose Johnson & Johnson (J&J) shot or completing the two-dose Moderna or Pfizer vaccination.

Why the changes matter

In April, the CDC issued new guidance to laboratories recommending reducing the RT-PCR CT value to 28 cycles — but only for those fully vaccinated individuals being tested for COVID.

In an RT-PCR test — the gold standard for detecting SARS-CoV-2 — RNA is extracted from the swab collected from the patient. It is then converted into DNA, which is then amplified.

CT, or cycle threshold, is a value that emerges during RT-PCR tests. A CT value refers to the number of cycles needed to amplify viral RNA to reach a detectable level.

According to the Indian Council of Medical Research, a patient is considered positive for COVID if the CT value is below 35. In other words, if the virus is detectable after 35 cycles or earlier, then the patient is considered positive.

LATEST VIDEO