Looking back, 2025 may be characterized as “the year of measles in North America.” The U.S. has recorded its highest number of measles cases in more than 30 years, although cases have tailed off significantly in the last eight weeks and are only slightly higher than they were in 2019. The current per capita incidence of measles in the U.S. is roughly 4 per 1 million people.
While there is a cyclical component to measles every several years, declining vaccination rates are by far the largest factor in this increase. According to Johns Hopkins University, the average county-level vaccination rate in the U.S. for measles, mumps and rubella declined from 93.9% pre-pandemic to 91.3% post-pandemic, moving further away from the 95% herd immunity threshold necessary to limit the spread of measles. (There are actually far more people vaccinated in the U.S. than there were in 2000, when measles was “eliminated” but the U.S. population has risen by 20% since then, and the number of unvaccinated has outpaced the population rise.)
This is simply the latest illustration of the importance of vaccines. Even small decreases in vaccination rates can have big consequences.
Which brings us to Health and Human Services Secretary Robert F. Kennedy Jr. and his fraught relationship with the mRNA vaccine, the unique delivery system that carries genetic material into the body’s cells to create an immune response against viral proteins. Under Kennedy’s guidance, HHS will gradually wind down its mRNA vaccine development programs and cancel 22 vaccine projects that have funding totaling $500 million. Some mRNA contracts in their final stages will be allowed to conclude, but no new mRNA projects will be put in place. The government is essentially getting out of the mRNA business.
During the COVID-19 pandemic, Operation Warp Speed, the federal initiative to rapidly develop an mRNA vaccine for the coronavirus, saved thousands of lives in the U.S. and millions of lives worldwide. The immune response created by the vaccine conferred relative protection for those infected and the severity of COVID-19 infections gradually declined. Besides this, those vaccinated with the mRNA vaccine were at less risk of developing post-COVID-19 persistent fatigue and other physical problems, known as long COVID. Recent data from a national study led by Rush University in Chicago found that those who did develop long COVID returned to full employment with fewer financial hardships if they had been vaccinated.
Not that the mRNA-powered COVID-19 vaccine was perfect. It decreased disease severity but did not prevent infection or transmission. The immunity it confers is short-lived, so patients must be revaccinated at frequent intervals. Side effects are rare, but heart inflammation in young men is not uncommon.
Kennedy’s oft-intemperate and sometimes-unscientific remarks about vaccines have generated fierce criticism from the public health community and much of the mainstream press. His critics have made equally intemperate remarks, suggesting that Kennedy will have the blood of millions on his hands. Not yet anyway, but it makes it difficult to analyze in sober fashion what Kennedy is doing.
What he is doing is rolling the dice. The strength of mRNA technology was that it could be developed and modified quickly in comparison to other non-mRNA vaccine technologies (almost nobody expected the mRNA COVID-19 vaccine to be ready as soon as it was). Scrapping mRNA research means the country might be unprepared upon the arrival of the next pandemic — whether it is a new COVID-19 strain, bird flu or some other agent that requires a rapid response. Kennedy and his HHS minions are redirecting efforts toward what they hope are improved technologies. He seeks vaccines developed with more transparency that are safer and more durable and can address the shortcomings of mRNA vaccines.
Maybe that will happen. Currently, other platforms include inactivated vaccines that use the actual organism to stimulate the immune system (flu vaccine); attenuated vaccines that use a weakened form of the organism to cause a mild infection (measles vaccine); and conjugate vaccines that use parts of the organism that don’t cause infection but train the immune system to respond (meningitis vaccine). But developing and testing new platforms takes time, and the vaccines created may still underperform in real-world usage.
Is Kennedy’s move to abandon mRNA research a calculated risk or a rash one? No one — not experts, the media nor the public — can say with confidence because the future and the science are uncertain. The next pandemic may occur in a year, a decade or a generation.
Answering that question will require patience, intellectual honesty, humility and wisdom. The Kennedy family has always walked the fine line between fantastic luck and accomplishment on one side and tragic misfortune on the other. Let’s hope the Kennedy luck is with the country here.
Dr. Cory Franklin is a retired intensive care physician and the author of “The COVID Diaries 2020-2024: Anatomy of a Contagion as it Happened.” Dr. Robert Weinstein is an infectious disease specialist at Rush University Medical Center.
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