<p>In less than three weeks, American medicine produced two significant milestones.</p>
<p>On August 5, the Food and Drug Administration (FDA) approved MFLUSIVA, Moderna’s influenza vaccine for adults 50 and older — the first flu vaccine in the United States developed with messenger RNA (mRNA).</p>
<p>Two weeks later, Moderna and Merck announced positive Phase 3 results for an individualized mRNA treatment intended to prevent high-risk melanoma from returning after surgery. This marked the first positive Phase 3 result for an mRNA-based cancer therapy.</p>
<p>This second achievement warrants further explanation.</p>
<p>Messenger RNA serves as a temporary set of biological instructions. For this treatment, scientists analyze mutations in an individual patient’s tumor and create an mRNA therapy designed to instruct that patient’s immune system on what to target. Unlike preventive vaccines, this is a therapeutic cancer vaccine personalized to one patient’s tumor.</p>
<p>The therapy was combined with Keytruda, Merck’s widely used immunotherapy, which aids the immune system in attacking cancer by releasing one of the brakes tumors can impose. The notable finding is that the addition of the personalized mRNA therapy yielded better results than Keytruda alone.</p>
<p>However, this is not the conclusion of the scientific process.</p>
<p>Moderna and Merck have released top-line findings, not the complete dataset. The details still need to be presented and scrutinized by scientists, and typically published for peer review. If the results are validated, they could support an application to the FDA, which would independently assess whether the benefits justify the risks. A successful Phase 3 trial — the large, late-stage study generally intended to provide evidence for regulatory decisions — is a significant milestone but does not equate to approval.</p>
<p>Science does not conclude with the issuance of a press release.</p>
<p>Moreover, not every mRNA experiment succeeds. Moderna’s Phase 3 norovirus vaccine recently did not meet the statistical criteria for early success, and the company is continuing its study.</p>
<p>One program faced disappointment. Another led to an approved influenza vaccine. A third has now produced a potentially historic cancer result.</p>
<p>These developments extend beyond mRNA. They demonstrate the implications when new medical evidence conflicts with established conclusions by policymakers.</p>
<p>Science begins with a question, develops a hypothesis, and designs an experiment that allows for the hypothesis to be tested. The results must then be accepted. Public policy should follow this process.</p>
<p>This is why these medical milestones present a complex relationship with Health and Human Services (HHS) Secretary Robert F. Kennedy Jr.’s statements.</p>
<p>Last year, Kennedy’s HHS directed BARDA to wind down 22 mRNA vaccine-development investments totaling nearly $500 million. BARDA — the Biomedical Advanced Research and Development Authority — is the federal program that aids in developing vaccines and other medical countermeasures against pandemics and national health threats.</p>
<p>Kennedy stated that the “data show these vaccines fail to protect effectively against upper respiratory infections like COVID and flu” and that HHS was “moving beyond the limitations of mRNA.”</p>
<p>One year later, his own FDA approved an mRNA vaccine against influenza.</p>
<p>This apparent contradiction merits examination rather than being dismissed as a political point. Earlier this year, the FDA initially declined to review Moderna’s flu vaccine application due to concerns regarding the trial design but later reversed its decision and accepted it. In June, the FDA’s outside vaccine advisers unanimously concluded that MFLUSIVA’s benefits outweighed its risks. The FDA granted approval in August.</p>
<p>From an external perspective, it is unclear how much of this reflects Kennedy allowing FDA scientists the necessary space to operate, how much is due to leadership changes within the FDA, or simply the regulatory process at work. If Kennedy permitted the evidence to guide decisions even when it contradicted his previous assumptions, he deserves acknowledgment.</p>
<p>However, the same principle must apply in other contexts.</p>
<p>I have previously argued that enthusiasm for unapproved peptides cannot replace evidence and that patient demand and influencer medicine cannot substitute for rigorous trials.</p>
<p>The standard should remain consistent regardless of whether politicians are supportive or skeptical of a treatment. The standard of proof must be upheld.</p>
<p>Kennedy’s own HHS advocates for “Gold Standard Science” based on reproducibility, transparency, constructive skepticism, falsifiable hypotheses, peer review, and acceptance of negative results.</p>
<p>These are commendable principles. However, skepticism is not evidence, and suspicion does not equate to a result.</p>
<p>This is significant as the administration is currently revising childhood vaccine policy. President Donald Trump has proposed reducing the number of vaccines routinely recommended for children and separating the measles, mumps, and rubella vaccine into individual shots. HHS is also seeking public input on new recommendation categories, including vaccines recommended “with qualification” or “but not during infancy.”</p>
<p>Revisiting vaccine policy is not inherently problematic. Medical recommendations are not immutable. Improved evidence should have the capacity to modify, narrow, or overturn them.</p>
<p>However, the evidence must precede any changes.</p>
<p>The melanoma result does not validate every mRNA product. The norovirus setback does not discredit the technology. The approval of MFLUSIVA does not imply that the next mRNA vaccine should automatically receive approval.</p>
<p>Kennedy claims he desires gold-standard science. MFLUSIVA may exemplify what that entails: scientists pose the question, the data provide the answers, and policymakers accept the results — even when they complicate prior beliefs.</p>
<p><em>Arie Blitz, M.D., M.B.A., is a retired physician and independent writer in Weslaco, Texas, who writes on foreign policy, medical ethics, and public policy.</em></p>