Despite significant drama from Trump officials this year, the Food and Drug Administration has for the first time approved a flu vaccine that uses mRNA technology.

On Thursday, vaccine maker Moderna announced that its flu shot, mRNA-1010, aka mFLUSIVA, had earned approval for use in all adults ages 50 and up. The approval announcement follows a unanimous vote by FDA advisors in June to approve the vaccine. That vote was based on its superior efficacy to existing seasonal flu shots and a good safety record demonstrated in trials that included nearly 44,000 people. After that vote, the FDA set a goal of August 5 for a decision on the vaccine’s fate.

While the unanimous support from FDA advisors boded well for Moderna’s shot, the overall path to approval was treacherous and uncertain, even until the end. For one thing, current Health Secretary Robert F. Kennedy Jr. is a well-established anti-vaccine advocate who has worked diligently in his time in office to thwart vaccinations. One of his first acts as health secretary was canceling a federal campaign to encourage people to get flu shots in the midst of a bad flu season—despite the fact that the Centers for Disease Control and Prevention had already paid for the campaign and the flu season was killing relatively high numbers of children.

Kennedy is also openly hostile to mRNA vaccines, having called the mRNA COVID-19 vaccine the “deadliest vaccine ever made” and canceling hundreds of millions of dollars’ worth of federal research grants for mRNA technology.

In February, Trump appointee Vinay Prasad—a Kennedy ally—refused to even review the vaccine, despite objections from FDA staff and career officials, shocking Moderna and the larger biomedical community. Prasad defended his decision by arguing that the company didn’t compare its mRNA vaccine’s efficacy to the correct existing vaccine. But Moderna firmly and publicly pushed back, noting that FDA officials previously signed off on its trial designs. The FDA reversed Prasad’s rejection the following week, and Prasad was pushed out of the agency at the end of April amid a series of controversial and widely decried moves.