WASHINGTON (NEXSTAR) ─ Members of the White House Coronavirus Task Force updated Senate lawmakers Wednesday on the nation’s response to the pandemic.

Several lawmakers, including Sen. Elizabeth Warren, D-Massachusetts, expressed their concerns over the production of a safe and effective vaccine.

“Vaccines are our best chance to end this pandemic,” she said.

Dr. Anthony Fauci, the nation’s top infectious disease expert, said that they should know by the end of the year whether any of the vaccines currently being studied can be safely mass produced.

“We feel cautiously optimistic that we will be able to have a safe and effective vaccine, although there is never a guarantee of that,” Fauci said.

Commissioner of the Food and Drug Administration (FDA) Dr. Stephen Hahn said science, not politics, will determine when a vaccine will be ready for the public.

“The FDA will not authorize or approve a vaccine that we would not feel comfortable giving to our families,” Hahn said. “FDA will not permit any pressure from anyone to change that.”

The nation recently surpassed 200,000 deaths from COVID-19. The experts told lawmakers that, until a vaccine is ready, testing is key.

“This month we will have available, on average, 3 million tests per day,” Assistant Secretary of Health Admiral Brett Giroir said.

But Sen. Chris Murphy, D-Connecticut, raised concerns that the testing guidance issued by the Centers for Disease Control and Prevention (CDC) has been confusing.

“I’ve read it 20 times and I don’t see anywhere in this guidance where it tells people they should get a test,” Murphy said. “I don’t see anywhere in this guidance where it tells them they should go see a doctor.”

Sen. Lamar Alexander said expanded testing is key to helping Americans regain normalcy the quickest.

“This explosion of many cheap reliable diagnostics tests are our best weapon,” Alexander said.