Moderna

The U.S. COVID-19 vaccination program has gone from zero to 50% in less than six months. As of Tuesday afternoon, the Biden administration said, half of the country's adults are now fully vaccinated against the coronavirus.

Children have now received their first doses of Moderna's COVID-19 vaccine, as the company studies the safety and effectiveness of the vaccine for kids ages 6 months to less than 12 years old.

The new guidance is specific to freedoms that vaccinated people can resume in their own homes, but the agency warns that everyone – even those who are vaccinated – should continue to follow recommended guidelines in public settings, including masking.

As the newest coronavirus vaccine makes its debut, the American public has a new set of deliberations before walking into their vaccine clinic — go with the new arrival or stick with the two vaccines that have already gone into the arms of more than 50 million Americans?

A third COVID-19 vaccine is on the way, and this one requires only one shot for immunization. The Food and Drug Administration authorized Johnson & Johnson's vaccine for emergency use Saturday, a day after a panel of advisers to the agency voted unanimously (22-0) in its favor.

In clinical trials, the Johnson & Johnson vaccine appears to be 66% effective at preventing moderate to severe cases of COVID-19 — compared to about 95% for Moderna and Pfizer. That has some people wondering if they should avoid the Johnson & Johnson vaccine. Absolutely not, says Dr. Ashish Jha, dean of the Brown University School of Public Health.

Vaccine supply chains are extremely specialized and sensitive, relying on expensive machinery, highly trained staff and finicky ingredients. Manufacturers have run into intermittent shortages of key materials, according to the U.S. Government Accountability Office; the combination of surging demand and workforce disruptions from the pandemic has caused delays of four to 12 weeks for items that used to ship within a week, much like what happened when consumers were sent scrambling for household staples like flour, chicken wings and toilet paper.

President Biden has finalized deals to buy 200 million more COVID-19 vaccine doses from Pfizer and Moderna by the end of July, increasing the likelihood of delivering on his promise to have all Americans inoculated by mid-summer.

President Biden announced Tuesday that his administration is working to purchase an additional 200 million doses of the two COVID-19 vaccines that have been authorized for emergency use, with the goal, the White House says, of having enough vaccine supply for the entire adult U.S. population by the end of the summer.

As reports emerge across the country of health facilities throwing out unused and spoiled COVID-19 vaccines, some state governments are failing to track the wastage as required by the Centers for Disease Control and Prevention, leaving officials coordinating immunization efforts blind to exactly how many of the precious, limited doses are going into the trash and why.