A health care worker fills a syringe with the Pfizer COVID-19 vaccine in July in New York. U.S. officials are recommending that Americans get COVID-19 booster shots to shore up their protection amid the surging delta variant and evidence the vaccines' effectiveness is falling.

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A health care worker fills a syringe with the Pfizer COVID-19 vaccine in July in New York. U.S. officials are recommending that Americans get COVID-19 booster shots to shore up their protection amid the surging delta variant and evidence the vaccines' effectiveness is falling. / AP

Updated August 18, 2021 at 7:36 PM ET

COVID-19 booster shots of the Pfizer and Moderna vaccines are set to become available for all U.S. adults beginning next month, the country's top health officials announced Wednesday.

"We know that even highly effective vaccines become less effective over time," Dr. Vivek Murthy, the surgeon general, said at a White House briefing. "It is now our clinical judgment that the time to lay out a plan for COVID boosters is now."

He added, "This includes our most vulnerable populations, like our health care providers, nursing home residents and other seniors. We will also begin delivering booster shots directly to residents of long-term care facilities."

People who received the Pfizer and Moderna vaccines will be eligible before Johnson & Johnson recipients

People 18 years and older who received the Pfizer or Moderna vaccines will be eligible for a booster dose eight months after their second dose, officials said.

The booster plan would go into effect starting the week of Sept. 20.

People who got the single-dose Johnson & Johnson vaccine would also likely need an additional shot to prolong its effectiveness against coronavirus infection and to reduce the severity of COVID-19 symptoms, health officials said. However, they are still conducting research and not yet releasing plans for booster shots for people who received that type of vaccine.

The data shows vaccines become less effective over time

The announcement comes as health officials across the country are battling a new wave of COVID-19 cases linked to the highly transmissible delta variant. The latest infections have once again pushed intensive care unit occupancy rates to the breaking point in multiple states, especially those with low rates of vaccination.

The surgeon general said that health officials were concerned about "waning immunity and the strength of the delta variant" — a "pattern of decline" that could "continue in the coming months."

In a statement released shortly before Wednesday's briefing, the U.S. Department of Health and Human Services cautioned that "the current protection against severe disease, hospitalization, and death could diminish in the months ahead, especially among those who are at higher risk or were vaccinated during the earlier phases of the vaccination rollout."

Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, cited three new studies in the CDC's Morbidity and Mortality Weekly Report that show reduction in protection from infection over time, including in nursing homes and against the delta variant. Effectiveness against severe disease, hospitalization and death remains relatively high, she said.

Dr. Anthony Fauci, the chief medical adviser to President Biden, said the plan for a booster is happening now because "if you wait for something bad to happen, you're considerably behind in your response." When it comes to the virus, he said, it's better to stay ahead of it than chase after it.

The White House says it's trying to make it easy for people to get the shots

Jeffrey Zients, the White House coronavirus response coordinator, said the aim was to make the administration of booster shots as easy as possible — and that they would be given at the same locations where people received their first and second vaccine doses.

He said 90% of Americans lived within 5 miles of one of the more than 80,000 vaccination sites across the country.

He also defended the plan to give Americans an additional dose while much of the rest of the world remained unvaccinated. The U.S. goal is to administer 100 million booster shots in the coming months. Over the same time period, 200 million doses would be donated to other countries, Zients said.

Biden addressed this issue himself, when he delivered remarks later Wednesday.

"We can take care of America and help the world at the same time," he said.

Biden also outlined plans to require nursing homes to vaccinate staff or risk losing Medicare and Medicaid funding.

"With this announcement," he said, "I'm using the power of the federal government, as a payer of health care costs, to ensure we reduce those risks to our most vulnerable seniors."

The Department of Health and Human Services is drafting the regulation to go into effect next month.

Since the start of the pandemic some 20 months ago, more than 623,000 people in the U.S. have died from COVID-19, according to figures tallied by Johns Hopkins University.

At Wednesday's briefing, the CDC's Walensky said the U.S. was averaging about 500 COVID-19 deaths per day.

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