The Case Against mRNA for Flu

The U.S. Food and Drug Administration has approved the first mRNA-based influenza vaccine, Moderna's mFlusiva, for adults aged 50 and over. It is a landmark decision that will no doubt be celebrated by supporters of mRNA technology as the next step in modern vaccine development.

For many others, however, the announcement raises an obvious question:

Why introduce a new mRNA flu vaccine when conventional flu vaccines already exist?

Unlike the situation in early 2020, when the world was facing a rapidly spreading pandemic with no approved vaccines, influenza has long been managed with a range of established vaccines using more traditional technologies. Those vaccines have decades of safety data behind them and continue to be widely available.

So why take the additional risk of a relatively new technology when the improvement in effectiveness appears to be modest?

Some Important Questions

In a recent video, Dr John Campbell carefully reviewed the FDA's approval documents and highlighted several aspects of the decision that deserve public attention.

His central argument is that new medical technologies should demonstrate clear and meaningful advantages before replacing existing alternatives—particularly when those alternatives already have established safety records.

One statistic immediately caught his attention.

Although headlines reported that the vaccine was around 27% more effective than a standard flu vaccine, that figure represents a relative improvement.

Looking at the absolute numbers, laboratory-confirmed influenza occurred in approximately:

• 2.8% of people receiving the standard vaccine.

• 2.0% of people receiving the new mRNA vaccine.

That represents an absolute reduction of roughly 0.8 percentage points—meaning that, compared with people already receiving a conventional flu vaccine, fewer than one additional flu case was prevented per 100 people vaccinated.

As Dr Campbell points out, whether that improvement is large enough to justify adopting an entirely new vaccine platform is a very real question.

More Reactions Than Conventional Flu Vaccines

The FDA documents also show that recipients of the mRNA vaccine experienced higher rates of expected vaccine reactions such as sore arms, fatigue, headaches and fever than those receiving the standard flu vaccine.

Most of these reactions were short-lived and not considered serious by regulators. However, Dr Campbell noted that the mRNA vaccine produces noticeably more serious adverse reactions. 

"Serious adverse events were reported in 2.2% of the recipients of mRNA-1010

Grade 3 solicited adverse reactions were reported by 6.4% of recipients of mRNA-1010 and 1.0% of recipients of the standard-dose comparator Adverse events of special interest in recipients of mRNA-1010 included thrombocytopenia 84 days after vaccination and cardiomyopathy 95 days after vaccination"

Given these more serious adverse events while delivering only a modest absolute improvement in protection, the overall benefit-risk balance deserves close scrutiny rather than automatic acceptance.

The Shadow of COVID

Public confidence in mRNA technology was profoundly affected by the COVID pandemic.

Millions of people believe legitimate questions about adverse events, myocarditis, long-term safety and vaccine effectiveness were dismissed rather than openly debated. It has undeniably left many people cautious about further expansion of the technology.

Against that background, regulators should arguably be setting an especially high evidentiary bar before approving new mRNA vaccines where effective alternatives already exist.

Existing Flu Vaccines Already Work

One important difference between COVID in 2020 and seasonal influenza today is that influenza vaccines are not a new field.

There are already several licensed vaccine technologies available, including traditional egg-based vaccines, cell-culture vaccines, recombinant vaccines and adjuvanted high-dose vaccines for older adults.

This naturally raises another question:

If existing vaccines already provide acceptable protection, what additional public health benefit is achieved by introducing an mRNA version?

Supporters argue that mRNA vaccines can be manufactured more rapidly and may eventually allow better matching to circulating influenza strains.

That may indeed prove valuable in future.

But that potential advantage has yet to be demonstrated in routine seasonal use.

Trust Must Be Earned

Medical innovation is essential.

Many breakthrough treatments began as new technologies that eventually proved themselves through careful testing and long-term experience.

But innovation alone is not sufficient.

Public trust depends upon transparent evidence, honest communication of both benefits and risks, and regulators demonstrating that new products offer meaningful improvements over existing options.

When a new vaccine platform offers an absolute improvement measured in less than one percentage point while producing more expected vaccine reactions than established alternatives, it is entirely reasonable for people to ask whether the evidence justifies the decision.

Those questions should not be dismissed as "anti-science."

They are precisely the questions that good science encourages us to ask.

After the controversies surrounding COVID, regulators should recognise that confidence cannot simply be demanded—it must be earned.

For many observers, including Dr John Campbell, this approval has yet to meet that standard.

Here is Dr John Campbell's video; -