President Joe Biden missed his Independence Day target of getting first shots into the arms of 70% of American adults. If he wants to convince the vaccine-hesitant to get immunized – especially vaccine-hesitant Republicans – there is a simple way to do so: Give Donald Trump the credit he deserves for the vaccines.

Former Presidents George W. Bush, Barack Obama, Bill Clinton and Jimmy Carter were all invited to record public service ads urging Americans to get vaccinated. The only former president not included was the one whose voice could have made the biggest difference – Trump.

This makes no sense.

Today, it is Trump supporters who are most likely to remain unvaccinated. The 20 U.S. states with the highest vaccination rates all voted for Biden in 2020. Meanwhile, most of the 22 states with the lowest vaccination rates went for Trump – including almost all of the states with vaccination rates below 50%. In conservative Mississippi, only 38.3% of adults are fully vaccinated, compared with 76.1% in liberal Vermont. A new Post-ABC News poll finds that while 86% of Democrats say they have received at least one dose, only 45% of Republicans have. And while just 6% of unvaccinated Democrats say they aren’t likely to get vaccinated, 47% of Republicans say they probably or definitely will not get shots against the virus.

If Biden wants to convince those Americans to get immunized, he should remind them that Operation Warp Speed – the greatest public health achievement in human history – was also the greatest achievement of the Trump presidency. Trump invested about $10 billion in six vaccine candidates – purchasing hundreds of millions of doses of vaccines before they were proven, and clearing away regulatory hurdles. All three vaccines that eventually received FDA approval received critical support from his administration. He provided $955 million to support the development of Moderna’s vaccine and another $1.5 billion to support large-scale manufacturing and distribution of the vaccine. He also pledged $1.95 billion for the purchase and nationwide distribution of 100 million doses of Pfizer’s vaccine, and $1.46 billion to purchase 100 million doses of Johnson & Johnson’s vaccine. And he provided $1.6 billion in support for Novavax, whose vaccine has been shown to be 90.4% effective and plans to file for FDA authorization in the third quarter.

Before leaving office, Trump had contracted to buy at least 800 million vaccine doses with delivery by July 31 – enough to vaccinate every single American. He put us on track to end the pandemic and get our lives back.

But instead of giving Trump credit for this accomplishment, Biden has tried to play down Trump’s role, falsely declaring that “my predecessor – as my mother would say, ‘God love him’ – failed to order enough vaccines.” Indeed, Biden has tried to take credit not only for vaccine distribution but also vaccine development, noting in a recent speech that “the science was done under Democratic and Republican administrations.”

This is childish.

Operation Warp Speed gave us the vaccines. Trump led it. It was his achievement. Full stop. Acknowledging this fact does not require Biden to gloss over what he considers Trump’s other manifold failures in office or his terrible behavior after the election.

Biden is the one who promised to usher in a new era of bipartisanship, so why can’t he admit his Republican predecessor’s role in delivering the vaccines that are saving us?

If Biden isn’t comfortable touting Trump’s achievement, he could ask Trump to do it. Does Biden really think that voters in Trump states are going to be persuaded by appeals from Carter, Clinton and Obama to get immunized? Apparently, Biden considered asking for Trump’s help. In March, he said, “I discussed it with my team and they say the thing that has more impact than anything Trump would say to the MAGA folks is what the local doctors, what the local preachers, what the local people in the community say.”

No, that’s not true.

Indeed, an appeal from Trump may very well be the only thing that would convince some of his supporters to get their shots.

Of course, Trump does not need to wait for an invitation from Biden. He could set up vaccination sites at his rallies, which would give him an opportunity to tout his administration’s singular success in saving us from COVID-19. And Republican governors in pro-Trump states could record public service ads of their own featuring Trump urging his supporters to get the vaccines his administration produced.

But though those efforts might be useful, it is the sitting president’s responsibility to convince Americans to get immunized. While the Biden administration deserves credit for the effective distribution of the vaccines, it was Trump who made the vaccines possible. The message to vaccine-hesitant Republicans should be: If you trust Trump, get your Trump vaccine.

– Follow Marc A. Thiessen on Twitter @marcthiessen.