While mRNA saved the COVID-19 day, GSK and Sanofi vaccines likely safe beyond pandemic: analysts

coronavirus vaccine
Novel mRNA technology faces hurdles in other diseases beyond COVID-19, good news for GSK and Sanofi, Jefferies analysts said in a note. (nevodka/iStock/Getty Images Plus/Getty Images)

Few knew about mRNA technology before the pandemic ushered the novel approach to the forefront of the fight against COVID-19. But while mRNA shots sailed through testing and have reached hundreds of millions of people so far, the tech won’t be the panacea for all other diseases, analysts say. 

To be sure, the mRNA COVID-19 vaccines from Pfizer-BioNTech and Moderna have shown “astonishing” efficacy, Jefferies analysts wrote in a note Wednesday following a conversation with an undisclosed “world pre-eminent expert” on vaccines and infectious diseases. Still, uncertainties remain in areas such as flu and cancer.

Following the mRNA success, experts have started speculating about which other diseases might be suitable for the novel approach. For their part, the Jefferies analysts said it's not clear how mRNA vaccines would stack up against more traditional methods of vaccine-making from industry heavyweights Sanofi and GlaxoSmithKline.

For those companies and Merck, established shots include pediatric combinations, plus vaccines against meningitis, shingles and HPV. There may be more room for mRNA developers to tackle cytomegalovirus virus or dengue, the Jefferies analysts wrote.

When it comes to the flu, rival mRNA developers have argued the technology, which uses messenger RNA instead of a weakened germ to instruct cells to trigger an immune response, could disrupt the multibillion-dollar market. 

Existing flu vaccines typically hold a low efficacy bar—roughly 30% to 60%—and can’t be quickly adjusted to target emerging strains like mRNA can. Except there may be some challenges in that arena as well, Jefferies analysts pointed out.

RELATED: Pfizer, after success in COVID-19, will go solo to develop other mRNA vaccines, CEO Bourla says

For one, it’s unclear whether one shot of an mRNA vaccine will work just as well as existing flu shots; a two-dose regimen could be a drawback. It’s also unknown how much governments would be willing to shell out for more effective flu vaccines.

Meanwhile, developing a cancer vaccine “has proven to be a hard nut to crack” and the probability an mRNA-based cancer shot would work is likely lower than viral vectors, Jefferies analysts said in the note.

Pfizer and Moderna have both pledged to plow ahead with the gene-based technology. Both companies are working on booster shots to tackle emerging coronavirus variants, and Moderna is testing a dual COVID-flu combo option. 

Jefferies noted that the combo shot, while conceivable, “could be complicated by the different mutation rates of the two viruses, plus potential for deleterious interactions and added manufacturing complexity.” 

Beyond COVID-19, Pfizer CEO Albert Bourla said in March that the drugmaker will try to use the technology against a host of other diseases. The drugmaker’s chief scientist, Mikael Dolsten, told investors on an earnings call that the technology could potentially be applied to flu, CMV and RSV.

RELATED: Moderna advancing early-stage mRNA prospects to show depth beyond COVID-19 shot

But the drugmaker will have to go head-to-head with Moderna, which has been developing drugs in the field over the last decade. The Cambridge, Massachusetts-based biotech has more than a dozen different mRNA candidates launched into clinical trials already with plans to further invest in the mRNA platform.

That’s not to mention the mRNA partnerships Sanofi and GSK drummed up recently. Sanofi is working with Translate Bio while GSK is teamed up with Germany’s CureVac to develop and a handful of mRNA infectious disease contenders.