Trump administration health officials are expected to miss the president’s deadline requiring they deliver new recommendations for childhood vaccinations by Sunday, according to people familiar with the matter.

President Donald Trump signed an executive order in August alongside Health Secretary Robert F. Kennedy Jr. that directed health officials to produce a plan within 90 days to split the combined measles, mumps and rubella immunization into separate shots. The order also asks that health officials submit plans to evaluate “the ideal timing” of childhood vaccines, develop alternatives to aluminum in some shots and improve safety monitoring.

The Department of Health and Human Services has submitted a draft of the plan to the White House, according to people familiar with the matter who were not authorized to publicly discuss internal deliberations. Kennedy had unequivocally promised plans by Nov. 8 during theg of the executive order.

“We will bring you actions and findings as soon as they are ready,” Kennedy said at the time. “We will not wait for the 90 day period. And within 90 days, as you have directed, we will deliver the full response required by this executive order.”An HHS spokesperson said the agency is actively implementing President Trump’s order. “The HHS Task Force on Safer Childhood Vaccines is working to strengthen vaccine safety research, improve transparency, and expand options for American families. This work requires careful scientific review, and HHS remains committed to advancing the president’s priorities through gold standard science and informed parental choice,” the HHS spokesperson said.

MMR vaccines are manufactured by Merck & Co. Inc. and GSK Plc.

The delay in recommendations comes amid the largest outbreak of measles the country has seen in decades and a threat to the country’s long-held elimination status. Next week, the Pan American Health Organization will convene to formally determine whether the US has seen continued transmission for more than 12 months, which would trigger the loss of its elimination status and signal the country does not have a handle on the highly contagious disease. While no vaccine is perfect, the MMR shot is considered 97% effective in preventing the disease after two doses.

The Centers for Disease Control and Prevention has recorded 5,182 cases across 45 states as of Nov. 6. Pennsylvania has the highest number of infections and has confirmed six measles-associated deaths. On Nov. 2, New York reported its first measles fatality in three decades. Three days later, Wisconsin announced its first fatality in an infant. The federal government has yet to acknowledge all of the deaths after Kennedy called into question the legitimacy of the first deaths in Pennsylvania, sparking a political fight with Governor Josh Shapiro. The CDC is working with a group of epidemiologists to determine a national definition of a measles death.

Top health officials sit on the task force making the plans. By law, officials leading the top US health agencies must have a seat in the group. The director of the National Institutes of Health chairs the group, which also includes the CDC director and the commissioner of the Food and Drug Administration. Kennedy, Trump’s incoming chief of staff Stephen Miller and the president’s pending nominee to be FDA commissioner, Heidi Overton, appeared alongside Trump at the executive orderg.

The required plan is the latest step in a series of attempts by Trump and Kennedy to pare down the nation’s childhood vaccine schedule, following a presidential memorandum in January and a May executive order that sought to align US shot schedules with countries that recommend fewer immunizations. The health agency in August solicited public comment on changing the categories of vaccine recommendations.