As the fall vaccination drive looms, over half of US children are left in limbo, facing uncertainty over their access to this year’s COVID-19 shot. The Centers for Disease Control and Prevention (CDC) has unexpectedly halted the distribution of vaccines to a key federal program and some states, causing a ripple in the nation’s immunization strategy.

Typically, the CDC would allow states to order the newly available vaccines through the federal Vaccine for Children (VFC) program, which provides vaccines free of charge to children who are uninsured, underinsured, Medicaid-eligible, or Indigenous people in the US. Approximately 52 percent of all US children are eligible for vaccines through this program.

Moreover, at least 11 states and one US territory are part of a universal vaccine purchase program, where they buy all vaccines for children, regardless of their ability to pay or insurance status, through contracts with the VFC. The states included are Alaska, Connecticut, Hawaii, Maine, Massachusetts, New Hampshire, New Mexico, Rhode Island, Vermont, Washington, Wyoming, and American Samoa.

Demetre Daskalakis, who was previously the director of the CDC’s National Center for Immunization and Respiratory Diseases, stated that the delay in VFC means a delay in these states’ ability to get vaccine for all children. In a statement, the Department of Health and Human Services (HHS) told Ars Technica that ‘CDC has not yet finalized procurement decisions for COVID-19 vaccines through the Vaccines for Children and Section 317 programs.’ The department, currently run by Robert F. Kennedy Jr., an ardent anti-vaccine activist, declined to answer the question of why there was a delay in the decision.

The unexplained delay aligns with Kennedy’s long-standing disdain for COVID-19 vaccines, which he has falsely called ‘the deadliest vaccines ever made’ and has actively tried to blame for the deaths of children, despite no evidence to support his claims.