11 Nov 2020

Covid-19 vaccine: Some unknowns and distribution a challenge

11:36 am on 11 November 2020

It's unclear how long the protective effect of the Covid vaccine which could be available in the country next year will last, a New Zealand scientist says.

A lab technician testing potential vaccines at a lab in France. The company, Sanofi, is testing to find a vaccine for Covid-19.

Photo: AFP

US drug company Pfizer has announced the coronavirus vaccine it is developing with German company BioNTech appears to be more than 90 percent effective.

New Zealand has an agreement with the companies to supply 1.5 million vaccines - enough for 750,000 people - subject to it passing all clinical trials and being approved by Medsafe.

Research, Science and Innovation Minister Megan Woods told Checkpoint the Ministry of Health would put together an immunisation plan on who would get the vaccine.

She said frontline border staff and people with increased susceptibility were likely to be among those to receive it first - and if everything went to plan, some doses could be delivered to New Zealand early next year.

College of GPs medical director Dr Bryan Betty said the government would need an expert group to look at the transport and distribution of the vaccine.

He said it had to be transported at minus 80C and GPs did not have the means to accommodate that yet.

"This is very different from the normal vaccines we use such as the flu vaccines."

Betty said vulnerable groups including the elderly, people with conditions such as diabetes, and Māori and Pacific communities should be prioritised to access it first.

Healthcare workers who potentially interact with Covid patients and border staff were also a priority, he said.

"The experience of the last few months has shown us the border is the place where Covid breaches, or comes through into New Zealand, so obviously the border starts to become a high priority in terms of an additional layer of protection with use of a vaccine.

"What we know is the Pfizer vaccine is one of many, many vaccines that are in development across the world ... there's likely to be other vaccines that start to come on stream over time."

The companies had to complete phase 3 trials and safety data collection so the vaccine was close but "not quite there yet", he said.

Pfizer and BioNTech say they will have enough safety data by the third week of November to take their vaccine to regulators.

Until it has been approved it will not be possible for countries to begin their vaccination campaigns.

The two companies say they will be able to supply 50 million doses by the end of this year and around 1.3 billion by the end of 2021. Each person needs two doses.

No vaccine has gone from the drawing board to being proven highly effective in such a short period of time.

The vaccine has been tested on 43,500 people in six countries and no safety concerns have been raised.

Some unknowns remain, however, including how long its protective effect might last.

Professor Graham Le Gros, director of Wellington's Malaghan Institute, said the trial on 43,500 people was carried out at 120 sites around the world and had covered different ethniticies.

Though it was a very good test, vaccines usually need several years of making sure nothing occurs, he said.

"We don't know whether it stops spread, we don't know a few other things yet, we just know that people didn't get sick.

"We know that it should be safe, up 'til now, and we know that it seems to be effective at the best rates that we can expect for a vaccine.

"How long that protective immunity will last for - we don't know until a few years down the track."

There will need to be several types of vaccines tried out in global population because it's not clear yet how long their effect will last, he said.

- RNZ / BBC

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