Washington, D.C. — Republicans on the House Energy and Commerce Committee sent a letter to Centers for Disease Control and Prevention (CDC) Director Rochelle P. Walensky as another step in their ongoing investigation into the origins of the COVID-19 pandemic. The letter to Dr. Walensky asks for a staff briefing to provide an update on CDC's investigative studies as to when COVID-19 may have first arrived in the United States, and if their studies indicate that it arrived earlier than the current official date of January 20, 2020.

WHY THIS MATTERS: It’s extremely relevant and important to the COVID-19 origin investigation. There needs to be an expanded CDC investigation and study to determine a more accurate date for when SARS CoV-2 first arrived in the United States. This information and new data will be important to constructing models that can make stronger determinations about when cases from China arrived in the U.S.

This will also provide new data to calculate the approximate date of the first cases in China. With China blocking access to information, relevant medical records, and patient samples, this strategy of tracing back America’s first cases may be the best shot to draw these key conclusions around the origin of the COVID-19 pandemic.

KEY: This request from Energy and Commerce Republicans is the first request to the CDC asking for a new study for potential COVID-19 cases before December 13, 2019. In the search for scientific proof, the Committee is specifically asking the CDC to 1) widen their testing base, 2) use the most accurate tests available to test blood samples, and 3) investigate unexplained deaths.

LETTER EXCERPT: “We write to request information and a briefing from the U.S. Centers for Disease Control and Prevention (CDC) that will assist us in our inquiry into the origins of SARS-CoV-2, the virus that causes COVID-19. As Republican leaders of the Committee on Energy and Commerce, the Congressional Committee with jurisdiction over public health, we strongly support an independent, comprehensive investigation into the origins of the COVID-19 pandemic, including the possibility of an accidental laboratory leak.

“In investigating the origin of the pandemic, it is essential to uncover the most accurate information necessary to determine when the first case of SARS-CoV-2 occurred.”

CLICK HERE to read CBS News' exclusive reporting on this letter.

CLICK HERE to read the letter to CDC Director Walensky.

CLICK HERE to read about the COVID-19 origin investigation.