The drug hydroxychloroquine, once touted by Donald Trump as a pandemic “game-changer,” should not be used to prevent Covid-19 and has no meaningful effect on patients already infected, a World Health Organization expert panel said.

A U.S. official told a World Health Organization meeting that Washington would participate in a program to boost Covid-19 testing, diagnostics and vaccines as the country joins global efforts to respond to the pandemic.

The U.S. Centers for Disease Control and Prevention is stepping up efforts to track coronavirus mutations and keep vaccines and treatments effective against new variants until collective immunity is reached, the agency’s chief said.

Joe Biden is resetting the United States’ response to the Covid-19 crisis after being sworn in as president to lead a country reeling from the nation’s worst public health crisis in more than a century.

Pfizer Chief Executive Officer Albert Bourla said his company supports Joe Biden’s $1.9 trillion coronavirus-focused plan that is intended to boost vaccination efforts and address the pandemic.

U.S. President-elect Joe Biden said he would order increased production of syringes and other supplies to ramp up vaccinations against Covid-19 and improve upon the Trump administration rollout that he called a “dismal failure.”

As the events that unfolded in Washington on Jan. 6 captured the nation’s attention, the raging coronavirus pandemic claimed its highest U.S. death toll yet, killing more than 4,000 people in a single day according to a Reuters tally.

German biotech firm CureVac agreed to an alliance with drugmaker Bayer to get global support in seeking approval for the company’s experimental Covid-19 vaccine and for distribution, the daily Bild reported.

The U.S. Food and Drug Administration warned health care personnel not to make any changes to the dosing of Covid-19 vaccines and that doing so would place the public health at risk and undermine “the historic vaccination effort to protect the population.”

As Operation Warp Speed – the Trump administration’s program to develop and distribute a Covid-19 vaccine – struggles to ramp up vaccinations, one of the approaches under consideration is cutting the doses of the Moderna vaccine.