Pfizer ups pressure on Merck with Prevnar, flu vaccine co-dosing study

Pfizer's new Prevnar 20 conjugate pneumococcal vaccine can be dosed at the same time as the seasonal flu jab, without any impact on either shot's effectiveness, according to a new study.

The results in adults aged over 65 showed that giving the two vaccines at the same time was just as effective as administering them a month apart, with a similar side effect profile.

The results come just ahead of a Centers for Disease Control and Prevention (CDC) advisory committee meeting that is scheduled to review how Prevnar 20 and a rival conjugate vaccine from Merck & Co – Vaxneuvance – should be used in adults.

Data showing that Prevnar 20 can be administered alongside the flu jab could provide more convenience for patients, who would be able to book in for both shots at the same time and avoid two clinic visits.

That could lend Pfizer's shot an edge over Vaxneuvance in the adult market, although Merck has suggested it sees the biggest opportunity for its new shot in the larger childhood vaccination category.

"Both Prevnar 20 and the influenza vaccine are important for helping protect adults against pneumococcal pneumonia and the flu respectively," said Pfizer Vaccines' chief medical officer Luis Jodar.

"However, vaccination rates decline when someone needs to make multiple appointments to receive these vaccines," he added.

Prevnar 20 was approved in June, and provides protection against 20 pneumococcal serotypes, seven more than the current Prevnar 13 shot that made almost $6 billion in sales for Pfizer last year, dominating a market worth around $8 billion.

Merck sells an older pneumococcal vaccine called Pneumovax 23, which protects against 23 strains but is a polysaccharide based shot and doesn't stimulate as strong an immune response as the conjugate jabs.

Vaxneuvance – which targets 15 serotypes – is key to Merck's plan to boost market share. It was approved for adults in July, and is due to be filed for paediatric use before the end of the year.

That could give it a valuable lead over Prevnar 20, as Pfizer doesn't expect to have its phase 3 results in children until next year.

Pfizer meanwhile is also running a phase 3 trial looking at co-administration of Prevnar 20 with its COVID-19 vaccine Comirnaty, anticipating a situation in which booster shots against the coronavirus might be administered every year.