New Zealand is on track to have two Covid-19 vaccine options available by the end of August following provisional approval by Medsafe of the Janssen vaccine for use in over-18s yesterday .
Vaccine Alliance Aotearoa's Graham Le Gros said having two vaccine options will strengthen the country’s Covid-19 response.
He explained the most obvious difference between Pfizer and Janssen’s jabs was how it stimulates the immune system.
The Janssen vaccine is made up of another virus, which is harmless to people, that’s been modified to replicate the spike protein gene of SARS-CoV-2, Le Gros said.
Meanwhile, Pfizer’s Covid-19 uses RNA technology. This trains the body’s immune system to recognise SARS-CoV-2 by telling cells to create a similar “spike protein” that’s harmless.
There’s also a difference in its efficacy rates, Le Gros said.
The decision on the single dose Janssen vaccine coming as 500,000 people have now been officially vaccinated.
According to data from the World Health Organization, one shot of the Janssen vaccine has an efficacy of 66.9 per cent against symptomatic moderate and severe cases of Covid-19. Meanwhile, the two-dose Pfizer vaccine has an efficacy of up to 95 per cent.
Le Gros said while current data showed Janssen’s vaccine was a “little bit less effective” at stopping Covid-19 transmission, it worked against all identified variants.
The Janssen vaccine is also easier to distribute because it didn't’ need to be stored at ultra-cold temperatures like Pfizer, he said.
He said the fact it was a one-dose vaccine meant it could be suitable for people who didn’t have the time to get two jabs.
“It just gives the New Zealand Government, the New Zealand population another option.”
Johnson & Johnson's Janssen vaccine secured provisional approval status after being assessed for three months by Medsafe.
Once provisional approval is given, Ministry of Health officials provide advice to the Government to then make a decision about how it wants to use the vaccine.
Le Gros said it has only been provisionally approved for over 18s currently because of the lack of data.
“Data is still coming in for the Janssen [vaccine] for younger age groups. It doesn’t mean to say it’s less safe.”
New Zealand paid for two million doses of the Janssen vaccine in a November 2020 advance purchase agreement.
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