WASHINGTON (BLOOMBERG) - US President Joe Biden is fighting his war against the coronavirus shorthanded, as delays in the Senate and by his own White House have left several top US health posts unfilled.

Biden's team lacks a confirmed Health and Human Services secretary and surgeon general. And the president has yet to name permanent heads for the Food and Drug Administration, which approves vaccines, or the Centres for Medicare and Medicaid Services, which administers the government's two large health programmes for elderly, disabled and low-income people. Other roles are also unfilled.

The holes threaten to hamper the US's rebound from the virus and undermine one of the biggest promises of Biden's campaign. The logjam rests in large part in the Senate, which has found scant time to confirm Biden's key nominees as lawmakers haggled over how to split power and are now contending with the impeachment trial of former president Donald Trump.

The President isn't likely to see immediate relief. Xavier Becerra, Biden's pick for health secretary, won't even have Senate committee hearings until the week of Feb 22, though the planning remains fluid, aides familiar with the matter said. That would probably push any full confirmation vote into March.

The White House is stepping up the pressure.

"Frankly, it is disappointing that Congress, the Senate, is delaying any further in confirming his nomination at a time when thousands of people are dying every day of a pandemic and people need leadership at the top of an agency that has an important role to play," Press Secretary Jen Psaki said Wednesday.

HHS vacancies

Despite the delays, Biden's White House has kept its pandemic response in the forefront, steadily scaling up vaccine shipments and holding regular briefings to tout progress.

The administration itself is responsible for some of the delay. The White House hasn't said why Biden has yet to name a permanent FDA or CMS chief. The President named long-time FDA official Janet Woodcock as acting commissioner.

Both Woodcock, who was previously director of the agency's Centre for Drug Evaluation and Research, and Joshua Sharfstein, who served almost two years as the principal deputy FDA commissioner in the Obama administration, are in the running for the job.

Academics, physicians and patient advocates have unleashed duelling opinion pieces and letters singing the praises of either Woodcock or Sharfstein.

It's unclear when Biden will make a decision, but White House officials believe Woodcock is doing well in the acting role and haven't seen any missteps stemming from the lack of a permanent appointee, two officials familiar with the matter said.

Biden also hasn't announced a nominee for assistant HHS secretary for preparedness and response. "This office is critical when it comes to infectious disease emergency response," said Amesh Adalja, a physician and senior scholar at the Johns Hopkins Centre for Health Security.

Biden also hasn't picked someone to run the Centre for Medicare and Medicaid Innovation, though Elizabeth Fowler has emerged as the front-runner.

In the Senate, Becerra appears to be a linchpin for other key posts that are essentially on hold until he's confirmed.

Those include Biden's nominee for surgeon general, Vivek Murthy, who has previously served in that post, and Rachel Levine, chosen as assistant HHS secretary for health. Levine, previously Pennsylvania's top health official, would be the first openly transgender Senate-confirmed federal official.

"We're in the middle of a pandemic. The Senate should confirm these nominees as quickly as possible," said Senator Bob Casey, a Democrat from Pennsylvania who serves on the health committee.

The three "are highly qualified nominees with a wealth of experience."

Meanwhile, Biden is operating with essentially just two of his senior health officials in place: Rochelle Walensky, the head of the Centres for Disease Control and Prevention, who didn't require Senate confirmation, and Anthony Fauci, the longtime chief of the National Institute of Allergy and Infectious Diseases who is serving as the President's top medical adviser.

Several other aides shepherding the Covid-19 response have health backgrounds, including physicians, but don't hold senior agency roles.

Adds to 'uncertainty'

"While many highly competent professionals currently serve in acting positions of government leadership, the paucity of Senate-confirmed, high-ranking HHS officials only adds to the uncertainty of these times," said Howard Koh, a professor at the Harvard T.H. Chan School of Public Health who also served as an assistant HHS secretary under Barack Obama.

"A timely confirmation process for the HHS Secretary should be among the highest priorities right now," Koh added.

"And following that confirmation, the full HHS senior leadership team needs to be confirmed as soon as possible."

With a 50-50 Senate, Republicans and Democrats haggled over an organising resolution until just last week, a delay that halted the work of some committees, including health, which was left in limbo after the retirement of its chairman, Lamar Alexander.

Even so, the health committee agreed to hearings for Miguel Cardona and Marty Walsh - Biden's picks for secretaries of education and labour, respectively. But they didn't move forward with Becerra, a polarising nominee whom many Republicans view as too partisan. Republicans on the committee believe Cardona and Walsh are less controversial and more clearly qualified than Becerra, one Republican aide said.

Health secretaries typically receive a courtesy hearing from the health committee before advancing in the finance committee. Democrats, though, remain confident they'll be able to confirm Becerra, according to Democratic aides familiar with the process.

Becerra "brings decades of health care policy experience to the table and as the attorney general of our largest state has fought alongside Republicans and Democrats to expand access to Covid treatments and to hold opioid manufacturers' feet to the fire," said Andrew Bates, a Biden transition spokesman working on nominations.

Senator Patty Murray, a Democrat who chairs the health committee, will move quickly to schedule hearings for the nominees, according to a statement released by an aide.

The Finance Committee received Becerra's paperwork in late January and expects to hold a hearing this month, according to a statement from a spokesperson for Senator Ron Wyden, a Democrat who chairs the committee. Wyden looks forward to getting Becerra on the job quickly, the statement said.

The White House has moved forward with lower-level appointments.

"The Covid-19 response is being run out of the White House and is going full-speed ahead," said Leana Wen, a visiting professor at George Washington University's Milken School of Public Health. "Though I would think it would really help to have key permanent leaders in place."