Booster jabs ‘likely’ in future

Additional booster shots for Covid-19 vaccines may be needed in the future for the best possible protection from the virus, but an exact time frame is not yet known.

The topic of booster jabs emerged yesterday after Pfizer chief executive Albert Bourla took part in a panel discussion hosted by US news network CNBC.

Bourla explained that at this stage, it is ‘‘likely’’ that a booster shot will be needed within 12 months of the initial two-dose vaccine regimen.

However he, and experts, all agree that more research is needed in this area.

The Pfizer/BioNTech vaccine is a twodose jab given at least three weeks apart. It’s currently the only Covid-19 vaccine to be given provisional approval by Medsafe for use in New Zealand.

Bourla said a likely future scenario is that people will need a booster shot – a third dose – of a Covid-19 vaccine, possibly within a year of getting fully vaccinated.

They may also need annual booster shots.

But Bourla reiterated that this is yet to be confirmed, and further data is needed.

The vaccine’s manufacturers, Pfizer and its German partner BioNTech, are currently studying how long the protective immunity of the vaccines will last for.

Previous data from clinical trials have found that the Pfizer vaccine was just over 91 per cent effective. Further analysis also found that the vaccine offered high levels of protection for up to six months after the second dose.

Following a small study in adolescents, Pfizer also found that its vaccine was safe and strongly protective in children as young as 12.

Dr Nikki Turner, the director of New Zealand’s Immunisation Advisory Centre, told Stuff there had always been an expectation that booster shots might be needed, but the time frame wasn’t known.

She explained there were two different and significant reasons for this – one being virus mutations, and the other being the issue of protective immunity.

At this stage, the vaccine was ‘‘effective against the current mutations in circulation in the world’’, but Turner said countries have to be prepared.

For example, if the virus significantly mutated and the vaccine was no longer highly effective, the formulation would need to be changed and booster shots would be needed.

This is a completely different issue to the duration of protective immunity, Turner said.

Currently, there are clear data showing that the Pfizer vaccine offers six months of protection.

Turner compared the Covid-19 jab to the influenza vaccine, saying that the reason the flu vaccine is annual is because the strains mutate, ‘‘and they mutate fast’’.

‘‘Flu viruses are more unstable than coronaviruses. So we don’t know whether this one will continue to mutate fast or not. So we will need boosters at some stage.’’

Referring to Bourla’s comments, Turner said his reference to boosters potentially being needed within a year was not because anyone knew for sure.

‘‘He’s saying we need to be planning and ready just in case.’’

In New Zealand, Medsafe is the regulatory body tasked with approving vaccines. In a statement to Stuff, Medsafe group manager Chris James said the discussion of a potential booster dose of the Pfizer vaccine has no impact on the rollout of the Covid-19 immunisation programme here.

‘‘Discussion of booster doses is speculation at this time and we have no data at present that determines whether a booster of the Pfizer vaccine might be needed. This is an area of intense study at the moment.’’