The next target of mRNA vaccines after Covid-19: influenza

MRNA vaccines have beaten many traditional approaches in the race to develop Covid-19 vaccines. Now they face an old viral enemy: the flu.

Sanofi SA, GlaxoSmithKline PLC and Pfizer Inc. are all working on seasonal influenza mRNA injections, betting that the technology will be more efficient, faster and cheaper to manufacture than traditional injections. But there are still great challenges to overcome: mRNA vaccines require ultra-cold storage and can cause unpleasant and, in very rare cases, dangerous side effects.

Influenza is an obvious target for mRNA vaccine development, experts say, as there is a lot of room for improvement of existing products. Current vaccines generally reduce the risk of having to see a doctor for the flu by 40-60%, but in some years the effectiveness can drop to almost zero. It’s a big deal for vaccine makers nonetheless, generating revenues of around $ 6 billion a year, according to EvaluatePharma.

Another drawback of traditional vaccines is their complex and slow manufacturing process, which has changed little since the development of the first vaccines in 1940. Inactivated versions of the target viruses are grown from chicken eggs, made harmless and purified, a process that can take six months. Meanwhile, new strains of the flu, which mutate faster than the coronavirus, may emerge, making vaccines less effective.

MRNA vaccines are much faster and easier to manufacture. Moderna Inc. assayed its first clinical trial patient just 63 days after learning the genetic sequence of the coronavirus. This is because mRNA vaccines only include a piece of genetic material – the part that contains the instructions for making the key protein on the surface of the virus – enclosed in a fatty particle.