Former National Institute of Allergy and Infectious Diseases Director Anthony Fauci has refused to appear before a second Senate panel investigating the COVID-19 pandemic, following his earlier testimony in which he invoked his Fifth Amendment right against self-incrimination more than 100 times. The refusal adds a new chapter to the prolonged congressional examination of decisions made during the pandemic response.

Fauci's invocation of the Fifth Amendment during the initial Senate probe was a notable departure from his prior public posture, having spent years as a prominent public face of the federal government's COVID-19 response. His legal team has not publicly detailed the specific lines of questioning that prompted the repeated use of the constitutional protection.

The Senate panel had sought a second appearance from Fauci, but he declined that request as well. Congressional investigators have been examining issues including the origins of the coronavirus, federal funding of gain-of-function research, and the basis for key public health guidance issued during the pandemic.

The Atlantic reported on text messages connected to Fauci that have drawn attention from investigators, adding texture to what lawmakers say they are trying to understand about internal communications during the early phase of the outbreak. The scope of the Senate inquiry has expanded as new documentary evidence has emerged.

Fauci has maintained through representatives that he is cooperating with lawful inquiries but has reserved his constitutional rights. Critics argue that his refusal to answer questions undermines public accountability, while supporters contend that the proceedings have become politically motivated. The Senate's next steps regarding enforcement or further subpoenas have not been announced.