It’s said that there are three ways that people learn; by example, repetition, or significant emotional event. That first, example, is also a powerful method of communication, and for that matter, often a key instrument of leadership. With that in mind, and given the virulence of this year’s flu strains, here’s look at how U.S. presidents have communicated (and instructed and led) on the topic of influenza and in particular getting annual, seasonal flu shots.
The first flu vaccine was available to the U.S. military in 1945 and to the general public one year later. (Interestingly, Dr. Jonas Salk, who would go on to develop one of the two major polio vaccines, was also instrumental in creating the influenza vaccine.)
Given the power of the bully pulpit, the extraordinary persuasiveness of film, photography, and broadcast TV, and the proven efficacy of the flu vaccine, it’s surprising how little presidents have publicly communicated and led by example on this issue.
Below is a brief summary, from 1945 to the present, of presidents and the flu. Surprisingly, we have only one, verified photograph of any president having ever received a seasonal flu shot. For that we have President Barak Obama and his redoubtable White House photographer, Pete Souza, to thank.
Harry S. Truman (in office, 1945 – 1953)
A draft news article, dated January 16, 1953, by Jane Stafford, Science Service Medical Writer, stated: “At the White House, the President’s physician, Maj. Gen. Wallace H. Graham, said that the Truman family had been vaccinated against influenza in the past and would be in the future whenever he thinks they should be. But the current outbreaks apparently do not at present seem enough of a threat for Gen. Graham to advise the vaccination now.” 
Earlier, in July of 1952, Truman had actually been hospitalized for five days with three concurrent infections: “Alpha Streptococcus (strep throat), Hemophilis influenza (flu), and Neisseria catarrhalis, which infects the respiratory tract.”  But in keeping with the norms of the day, this was not revealed to the public. “On Monday, July 14,  Press Secretary Joseph Short revealed that Truman would stay in his quarters because he suffered from a "mild virus infection" and thought—he did not know for sure—that he had a "mild temperature." Asked if the President had a cold, Short replied, "Don't press me." Asked if he had the flu, Short said "[International News Service reporter Robert] Nixon is on the right track" (i.e., the President had a cold). He preferred that the press not reveal that the President was "up and down" or spent part of his time in bed sick.” 
Dwight D. Eisenhower (1953 – 1961)
Stafford’s article (see above), written just before Eisenhower’s first inauguration, went on to say: “President-elect Eisenhower’s physician, Maj. Gen. Howard McC. Snyder, told Science Service in a telephone interview that the question of vaccination of the Eisenhowers has been under consideration Nothing has been decided yet, however, and Gen. Snyder is not sure that he will advise it. He feels that right now would be a bad time because of the possibility of reaction. When asked whether he felt as some physicians do, that the vaccination against influenza is as bad as the disease, he chuckled but made no comment. President-elect Eisenhower was vaccinated against influenza when he was abroad, Gen. Snyder said.” 
The Eisenhower library reports that “President Eisenhower was only vaccinated for the flu on one occasion during his time in the White House. On August 26, 1957 he received the vaccination given by Dr. Howard McCrum Snyder, his personal physician. Snyder gave him the injection at the White House and there are no photographs of this event.” 
John F. Kennedy (1961 – 1963)
Though President Kennedy urged Americans to get vaccinated against polio , there is no record of him similarly encouraging vaccination against the flu. His own medical records are not available to the public, but may be viewed by researchers only by permission of the Director of the Archive and in the presence of a physician.
Lyndon Baines Johnson (1963 – 1969)
From his Presidential Daily Diary, we know only that President Johnson received a flu shot on September 26, 1968. There are no other mentions of flu vaccinations. The Johnson Library archivist speculates that perhaps flu shots were by then so routine they were not recorded.
Richard M. Nixon (1969 – 1974)
A review of President Nixon’s Presidential Daily Dairy shows no mention of his receiving a flu shot while in office. Nixon’s medical history is held as private and not available for research.
Gerald R. Ford (1974 – 1977)
Apparently, the only flu shot President Ford received was for the swine flu on October 14, 1976. He and his family received the vaccine on television and a photograph of Ford’s shot was widely circulated.
Jimmy Carter (1977 – 1981)
There is no record of President Carter ever receiving a flu shot.
Ronald Reagan (1981 – 1989)
From a March 11, 1985 press release, summarizing President Reagan’s recent physical and medical examination, we know that the president received yearly flu shots as well as “weekly hyposensitization allergy shots.” Photos of four of those shots area shown here, but judging from the dates, it’s unlikely they show flu vaccinations.
George H. W. Bush (1989 – 2009)
There is no record of President George H. W. Bush ever receiving a flu shot.
William Clinton (1993-2001)
From a December 14, 1999 White House press briefing, we know of at least one instance where President Clinton received a flu shot. 
George W. Bush (2001 – 2009)
There is no record of President George W. Bush ever receiving a flu shot.
Barak Obama (2009 – 2017)
The only photo we have definitively showing a president of the United States receiving a flu shot is that of Barak Obama on December 20, 2009. We also know that Michelle Obama receive the vaccination that same day and that their daughters received the shots earlier that year in October. 
Donald J. Trump (2017 - )
President Trump is known, not least, for his many contradictions, and his engagement with the flu is no different. After publicly courting Robert Kennedy, Jr. to head up a commission to inquiry, looking for links between vaccines and autism, and after claiming to have never received a flu shot, he apparently, and quietly, did so. 
My thanks to all of these who answered my research requests. Without knowing what this article would say, they were all prompt, courteous, and helpful. They are all, also, professionals at the National Archives and Research Administration (NARA), an agency whose work receives too little attention and too little support. They are:
Valoise Armstrong (Dwight D. Eisenhower Presidential Library, Museum and Boyhood Home), David Clark (Harry S. Truman Presidential Library & Museum), Malisa Culpetter (George W. Bush Presidential Library and Museum), Stacy Davis (Gerald R. Ford Presidential Library & Museum), Mary Finch (George Bush Presidential Library and Museum), Allen Fisher (LBJ Presidential Library), Christian Goos (Barack Obama Presidential Library), Melissa Heddon (Richard Nixon Presidential Library and Museum), Jason Kaplan (William J. Clinton Presidential Library), Emily Mathay (John F. Kennedy Presidential Library and Museum), Brian C. McNerney (Lyndon Baines Johnson Library and Museum), Jennifer Newby (Ronald Reagan Presidential Library), Michael Pinckney (Ronald Reagan Presidential Library), Herbert Ragan (William J. Clinton Presidential Library) Clara Snyder (John F. Kennedy Presidential Library and Museum).
 E-mail to author.