Auckland University vaccinologist Dr Helen Petousis-Harris is one of the leading voices in New Zealand about everything to do with vaccines, and has been doing immunisation-related research since 1998.

Chris McKeen/Stuff

Auckland University vaccinologist Dr Helen Petousis-Harris is one of the leading voices in New Zealand about everything to do with vaccines, and has been doing immunisation-related research since 1998.

EXPLAINER: As the Government plans to start vaccinating border workers this Saturday, questions, fears and theories about the Covid-19 vaccine continue to abound.

Earlier this month, Auckland University vaccinologist Helen Petousis-Harris​ debunked theories in a Stuff Q&A, incluing fears vaccine development had been rushed or that it contained a microchip to control the masses.

Petousis-Harris said it was fair to have questions and fears about the vaccine considering the large volume of misinformation circulating online.

But vaccine hesitancy could prevent the country from reaching the critical mass of immunised people needed to safely re-open the borders.

Petousis-Harris has answered more of the questions that have cropped up recently. Her responses are edited for clarity.

READ MORE:
* Covid-19 vaccine: Was it rushed? Is it safe? Could it be used to spy on the population? An expert addresses key questions and fears
* Frontline border workers to be vaccinated first as New Zealand approves Pfizer vaccine
* Coronavirus: New Zealand could look to Australia for AstraZeneca supply

One of the most popular theories circulating is that vaccines containing messenger RNA, which are strands of genetic code, could alter people’s DNA.

The Pfizer-BioNTec vaccine, which Medsafe has approved for use in New Zealand, is an mRNA vaccine.

The ultra-cold freezers for storing the Pfizer/BioNTech vaccine can get down to -80 degrees Celsius.

Ministry of Health

The ultra-cold freezers for storing the Pfizer/BioNTech vaccine can get down to -80 degrees Celsius.

Can mRNA vaccines alter your DNA?

No. The mRNA in the vaccine cannot enter the cell nucleus where your DNA is, neither could it integrate it nor alter it in any way.

What is actually in the vaccines?

Each vaccine has a slightly different formulation. The vaccine New Zealand is receiving this week (from Pfizer) consists of little pieces of ribonucleic acid (RNA) wrapped up in little spheres of fat, or lipids like cholesterol. This not only protects the fragile RNA but also helps it get into our cells. The vaccine also contains salts, which help balance the acidity, and sugar, which helps keep the vaccine happy during the freezing process.

Can the vaccine give you Covid-19? Is it a live vaccine?

There are no live Covid-19 vaccines on the near horizon. None of the currently approved vaccines can give you Covid-19 as there is no virus in them.

A small ampoule with a cannula for vaccination against Covid-19 with the vaccine from Pfizer-BionTech stands in the Cottbus vaccination centre in Cottbus, Germany.

Patrick Pleul/dpa/AP

A small ampoule with a cannula for vaccination against Covid-19 with the vaccine from Pfizer-BionTech stands in the Cottbus vaccination centre in Cottbus, Germany.

Are Covid-19 vaccines likely to be lucrative?

Most developers are not profiting from Covid-19 vaccines – at least not in the immediate future. Some have committed to no profit at all, such as AstraZeneca. The price in US dollars of Covid-19 vaccines is very low. For example, a dose of the Pfizer vaccine is about US$20 (NZ$27.7), Moderna about $30, AstraZeneca about $3 to $4, Janssen about $10, and Novavax about $16. These prices are much cheaper than other new vaccines.

Does the vaccine stop the transmission of the virus or does it just help alleviate symptoms?

Growing evidence indicates that the Covid-19 vaccines we are familiar with so far will also prevent transmission of the virus. Not all the studies assessed this as an outcome, so while we thought it likely that they would prevent transmission as well as getting sick, we had to wait for the evidence to start coming in. We can see the effect on transmission once we start using the vaccines widely.

Does the vaccine prevent asymptomatic disease?

Probably. Data is mounting that the vaccine will prevent asymptomatic disease very well. As this was not measured in the trials for the Pfizer vaccine we have to wait for real world experience. It is looking very positive. In contrast, AstraZeneca measured this in some of their trial participants and found that the vaccine did indeed prevent asymptomatic infection.

Is the vaccine safe for children, pregnant and breastfeeding women and people who have allergies?

So far the trials have included older children and people with a range of health conditions such as allergies. In terms of people who have allergies, only those who have a serious allergy to ingredients in the vaccine or a previous dose of vaccine should not have it. The consumers information sheet from Medsafe says the Covid-19 vaccine should not be given to children under 16 years. It advises people who have medical conditions, who take other medicines, or are pregnant or plan to become pregnant or are breastfeeding to seek advice with their doctor before getting the vaccine. This information could change as more data becomes available. For example as the clinical trials on children continue, the age range will likely move down to younger ones.

Were animals used in the trials?

All the vaccines have data from animals. Before vaccines are used in humans they are tested on suitable animal models. These will be animals that can mimic various aspects of human responses. For example to test if the vaccine prevents disease you need an animal that can be infected with the particular virus, in this case the SARS-CoV-2 virus. A lot of very important data comes from animal models. The final product does not contain animal products.



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