The Biden Administration’s booster vaccine plan has been messy and confusing, but at least it arrived at the right outcome. Credit to Centers for Disease Control and Prevention director Rochelle Walensky late Thursday for overruling the agency’s outside advisers and backing a broad booster rollout.

Last month White House officials and agency heads said they planned to make boosters available on Sept. 20. They were right to prepare, but boosters hadn’t been cleared by the Food and Drug Administration. Two senior career FDA...

Disease Control and Prevention director Rochelle Walensky

Photo: Michael Brochstein/Zuma Press

The Biden Administration’s booster vaccine plan has been messy and confusing, but at least it arrived at the right outcome. Credit to Centers for Disease Control and Prevention director Rochelle Walensky late Thursday for overruling the agency’s outside advisers and backing a broad booster rollout.

Last month White House officials and agency heads said they planned to make boosters available on Sept. 20. They were right to prepare, but boosters hadn’t been cleared by the Food and Drug Administration. Two senior career FDA officials told reporters they are leaving the agency because they disagreed with the White House booster plan.

Resignation is an honorable path if you can’t support a policy, but that doesn’t mean the dissenters are right. The preponderance of evidence supports boosters. Vaccine efficacy against infections has declined significantly for people who were vaccinated early this winter. Israel’s experience over the summer showed that more breakthrough infections were resulting in severe illness.

Some experts say boosters aren’t needed since vaccines still appear to be 80% or so effective against hospitalization. But some people with breakthrough cases are getting very sick even if they don’t land in the hospital. Others want to protect against the risk of long Covid or transmitting the virus to family.

An FDA outside panel last week hedged by backing boosters only for those over age 65 or at “high risk.” FDA Acting Commissioner Janet Woodcock on Wednesday endorsed this recommendation, but she defined “high risk” broadly to include workers who might have higher Covid exposure.

But experts on a CDC advisory panel on Thursday disagreed with her decision. Some said young, healthy people were at low risk for severe illness, so boosters weren’t necessary. Others worried that recommending boosters broadly would send the message that vaccines didn’t work. But the CDC’s job is to make decisions based on public health costs and benefits, and our guess is that tens of millions who are vaccinated will want booster shots as breakthrough cases increase.

Dr. Walensky overruled the CDC advisers and affirmed Dr. Woodcock’s recommendation, which is broad enough that most people who want a booster should be able to get one. The government will leave individuals to assess their own benefits and risks.

“As CDC Director, it is my job to recognize where our actions can have the greatest impact. At CDC, we are tasked with analyzing complex, often imperfect data to make concrete recommendations that optimize health,” Dr. Walensky wrote in a statement. “In a pandemic, even with uncertainty, we must take actions that we anticipate will do the greatest good.”

She’s right. The added protection against breakthrough infections will help the country get through what could be a rough winter. Experts predict that flu and other respiratory viruses will be more prevalent this year. Breakthrough infections could exacerbate the strain on the healthcare system and swell demand for monoclonal antibody therapies, which the Administration has been rationing.

A booster shot costs the government $20 compared to $2,100 for a monoclonal antibody treatment. A non-ICU Covid hospitalization costs $33,525. Add the health and economic benefits of fewer infections, and the cost-benefit analysis seems clear. The CDC has made many mistakes during the pandemic, but Dr. Walensky made the right call on boosters.

With elections fast approaching, Joe Biden and the Democratic Party are repeating their 2020 strategy of running against Donald Trump, realizing his name is a bigger driver of turnout than policy. Images: Getty Images/iStock Photo Composite: Mark Kelly The Wall Street Journal Interactive Edition