United States’ Department of Health and Human Services on Wednesday recommended coronavirus vaccine booster doses for all adults, noting that the protection offered by vaccines wanes over time.

Officials added that protection against mild and moderate Covid-19 cases was also diminishing due to the dominance of the Delta variant.

“Based on our latest assessment, 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,” the statement said. “For that reason, we conclude that a booster shot will be needed to maximize vaccine-induced protection and prolong its durability.”

But the government said that it will begin administering the booster doses only after the Food and Drugs Administration conducts an independent assessment of the safety and effectiveness of the third dose of vaccines developed separately by Pfizer and Moderna.

An advisory committee of the Centers for Disease Control and Prevention will then recommend the booster shots after reviewing the evidence, the health department said. The booster shots are expected to be rolled out by September 20. It will be provided to American citizens who received their vaccine doses eight months before the specified period.

“At that time, the individuals who were fully vaccinated earliest in the vaccination rollout, including many health care providers, nursing home residents, and other seniors, will likely be eligible for a booster,” the government said.

“We also anticipate booster shots will likely be needed for people who received the Johnson & Johnson vaccine,” the government said. “Administration of the J&J vaccine did not begin in the US until March 2021, and we expect more data on J&J in the next few weeks. With those data in hand, we will keep the public informed with a timely plan for J&J booster shots as well.”

The statement was jointly issued by the country’s leading health officials and medical experts, including Chief Medical Advisor to President Joe Biden, Dr Anthony Fauci, Surgeon General Dr Vivek Murthy, Acting Commissioner of Food and Drug Administration Dr Janet Woodcock and Director of the Centers for Disease Control and Prevention Dr Rochelle Walensky.

Earlier this month, Fauci had said that the country would administer booster shots to Covid-19 vaccine beneficiaries with weaker immunity before giving them to the rest of the population.

While Covid-19 vaccine doses are available widely in the US, unlike other countries, many people have chosen not to get vaccinated, according to Reuters. The daily cases in the US have climbed to more than 1,50,000 in August due to the Delta variant.

On August 1, Fauci warned that things would get worse as the Delta variant of the coronavirus had been found in more than 130 countries since it was first detected in India.

The US has so far recorded over 3.70 crore Covid-19 cases and more than 6.23 lakh deaths, according to the John Hopkins University data.

Germany, France and Israel have also decided to administer booster shots. Earlier in August, the World Health Organization had called for a pause in administering booster shots, at least till September, so that supplies can be used to help all countries vaccinate at least 10% of their population.