Health Officials Lay Out Plan for US COVID-19 Booster Shots in General Public

This article has been updated.

US health officials today announced a plan for any American over the age 18 who received a COVID-19 vaccine to become eligible for a booster shot 8 months following their second dose of an mRNA vaccine, beginning on September 20, 2021.

Separately, CMS announced it would require staff in the nation's over 15,000 Medicare- and Medicaid-participating nursing homes to be vaccinated against COVID-19, or face losing federal funds.

Wednesday's recommendation for universal booster shots is subject to the FDA conducting an independent evaluation of a third dose of the mRNA vaccines and the CDC’s Advisory Committee on Immunization Practices (ACIP) issuing booster dose recommendations based on a review of the evidence, according to a joint statement.

Meanwhile, Pfizer has already submitted phase 1 data to the FDA to support a booster dose for those who received the company's 2-dose regimen.

“If you are fully vaccinated, you still have a high degree of protection from the worst outcomes of COVID-19, severe disease hospitalization and death. So, we are not recommending that you go out and get a booster today,” stressed US Surgeon General Vivek Murthy, MD, during a press call. “Instead, starting the week of September 20, fully vaccinated adults could begin getting their booster shots, 8 months after their second shot of an mRNA vaccine.”

The 3 approved COVID-19 vaccines continue to remain extremely effective against severe COVID-19 outcomes but increasing cases of the Delta variant throughout the country and the fact that vaccines are associated with a reduction in efficacy over time contributed to the decision.

“The available data make very clear that protection against SARS-CoV-2 infection begins to decrease over time following the initial doses of vaccination, and in association with the dominance of the Delta variant, we are starting to see evidence of reduced protection against mild and moderate disease,” according to a statement attributed to CDC Director Rochelle Walensky, MD, MPH, and other federal health officials.

Booster shots will be available to all Americans at no charge regardless of immigration or insurance status, officials said.

For individuals who received the single-dose Johnson & Johnson (J&J) vaccine, booster shots are likely to be recommended, although agencies are waiting for the company to release data in the coming weeks. Rollout of the J&J vaccine began in March 2021.

The news comes after a CDC advisory committee endorsed the administration of booster shots for immunocompromised Americans on August 13. This group, in addition to health care workers, the elderly and nursing home residents, will likely be the first individuals to receive booster shots, as they made up the initial cohort of vaccine recipients when doses first became available.

The booster plan is also subject to modification should new data emerge. Nearly all Americans hospitalized with COVID-19 are unvaccinated, and the overwhelming majority of deaths are among unvaccinated individuals.

Although the statement notes the United States will continue to increase the supply of vaccines worldwide, the notion of introducing booster shots in wealthier countries has been met with contention among critics, including WHO Director-General Tedros Adhanom Ghebreyesus.

The global health organization has called for a moratorium on booster shots until at least the end of September, allowing less wealthy countries to vaccinate at least 10% of their respective populations.

Also Wednesday, the CDC released data from 3 studies supporting the plan for administering boosters to the general population, with one study conducted among nursing home residents revealing the efficacy of 2 doses of mRNA vaccines against COVID-19 infection decreased throughout the spring and summer of 2021.

Specifically, researchers found "2 doses of mRNA vaccines were 74.7% effective against infection among nursing home residents early in the vaccination program (March–May 2021). During June–July 2021, when B.1.617.2 (Delta) variant circulation predominated, effectiveness declined significantly to 53.1%."

The analysis found similar efficacy rates between the Pfizer and Moderna vaccines, but did not distinguish between asymptomatic and symptomatic presentations.

An additional study highlighted the efficacy of the 2 mRNA vaccines against hospitalizations, showing sustained protection over 24 weeks, although Delta-specific vaccine efficacy was not assessed.

A further analysis, conducted between May 3, and July 25 in New York found "the overall age-adjusted vaccine effectiveness against hospitalization in New York was relatively stable (91.9%–95.3%)." However, "the overall age-adjusted vaccine effectiveness against infection for all New York adults declined from 91.7% to 79.8%." Lower relative rates of new COVID-19 cases were seen among vaccinated individuals compared with unvaccinated persons.

Based on these findings, “while the exact percentage of vaccine effectiveness over time differs depending on the cohort and settings study, the data consistently demonstrate a reduction of vaccine effectiveness against infection over time,” Walensky said.

“Importantly, though, despite waning vaccine effectiveness against infection, data analyzed through July continue to demonstrate the stable and highly effective protection against severe illness and hospitalization for people who are vaccinated,” she added during a press briefing about the announcement.

Additional data released from Moderna showed that the booster mRNA vaccine increases antibody titers by at least 10-fold, Anthony Fauci, MD, explained, adding that Pfizer has released similar encouraging data. Trials were based off efficacy against the Delta variant. “You get a dramatic increase in antibody titers when you do a third immunization dose,” Fauci said.

“The current immunological data that indicate that antibody levels decline over time, higher levels of antibody are associated with a higher level of efficacy. Higher levels of antibody may be required to protect against Delta…and a booster mRNA immunization increases antibody titers by multiple fold,” he said.

Meanwhile, CMS, in its announcement regarding nursing homes, noted that only 62% of staff are vaccinated as of August 8 and a rise in cases among residents has been seen in facilities with low staff vaccination rates. State level vaccination rates range from 44% to 88%.

CMS will monitor vaccination rates through its National Healthcare Safety Network (NHSN).

“Keeping nursing home residents and staff safe is our priority," said CMS Administrator Chiquita Brooks-LaSure. "The data are clear that higher levels of staff vaccination are linked to fewer outbreaks among residents, many of whom are at an increased risk of infection, hospitalization, or death."