Dr Michelle Dickinson answers many of those ‘big questions’ about the COVID-19 vaccine in this set of videos.
Nanogirl (Dr Michelle Dickinson) vaccine videos
How does the vaccine work?
Vaccines work by safely helping our own immune system to recognise and train against a pathogen like a virus or bacteria. They do this by triggering an immune response that helps our immune system to learn how to attack and destroy the pathogen if our body is ever exposed to it again.
The Pfizer vaccine is designed to help us to build a long term immune response to the COVID-19 virus by exposing our body to a protein unique to the virus - known as the spike protein.
The active ingredient in the vaccine is mRNA, a molecule that is naturally found in every cell in your body. The Pfizer vaccine contains mRNA with instructions for how to build spike proteins similar to those found on the outside of the COVID-19 virus. Your ribosomes follow these instructions and build this spike protein on your own cell.
Your immune cells detect this newly made but unusual spike protein and destroy it. During this process they store information about the protein helping your immune system to be ready to attack quickly and efficiently if your body is exposed to the protein again - which might be because you are exposed to the COVID-19 virus.
What are the ingredients in the vaccine?
You can look up the ingredients on the medsafe or FDA website, to summarise they are:
- mRNA- the active ingredient. mRNA is the molecule that contains the instructions for ribosomes in your cells to make a protein similar to that found on the outside of the COVID-19 virus. Once built your immune system detects this protein and can safely figure out ways to destroy it quickly and effectively, saving that information as a memory to help you fight against the virus if you are ever exposed to it.
- Lipids – these are oils or fats that are used as a protective cushion that goes around the delicate mRNA molecule so it isn’t damaged as it’s being injected.
- Polyethylene glycol - this is used as a protective coating that goes around the delicate mRNA molecule to help stabilise it.
- Salts - these are used to help buffer the pH or acidity of the vaccine solution so it’s similar to those of your body fluids.
- Sucrose – this is sugar and used as a cryoprotectant to stop the tiny particles in the vaccine from losing their shape and sticking together during the intense freezing process.
- Water – this is the carrier that everything is held in.
What are the side effects of the vaccine?
Vaccines work by triggering your immune system which can produce responses by your body that indicate your immune system is working and responding!
With the Pfizer vaccine, most of these responses, or side effects show within a day or two after being vaccinated.
Initially we learned about side effects from the clinical trials that took place, but since then over 6 billion doses of different COVID-19 vaccines have been given and with that comes so much data around side effects experienced.
The Vaccine Adverse Event Reporting Form on the Medsafe website informs the Centre for Adverse Reactions Monitoring (CARM) which is a database of information about side effects to medicines and vaccines in New Zealand.
The most common side effects reported by New Zealanders have been dizziness, headache: and pain at the injection site.
After your vaccination you are required to stay for around 15 minutes. This is because any rare but severe reactions to the vaccine are likely to happen immediately after you receive it. All vaccination centres have medical professionals and medication to immediately treat you if you are one of these rare cases.
How do we know it is safe when it was developed so quickly?
There is a difference between fast and rushed, and while the COVID-19 vaccine was released much faster than previous vaccines, no steps were skipped or shortcuts taken in the testing process.
This vaccine has gone through just as much safety testing as previous vaccines that you may have had.
Scientific research needs to find funding and this application process can take a long time.
When COVID became a global issue, funders including governments, philanthropists and businesses contributed billions of dollars to help the research to continue.
The development of mRNA vaccines has actually drawn on the work of hundreds of researchers over more than 30 years, starting in 1978.
The mRNA COVID vaccine was able to take the results from decades worth of experiments to quickly create a new vaccine, based on what had been learned over the years.
All vaccines need to go through 3 phases of human clinical trials which test the safety, effective dose level, and efficacy of the vaccine. When COVID-19 became a global pandemic, tens of thousands of volunteers signed up for the trials.
While it might seem fast, a lot of the work on this vaccine had already been done, and the scientific community worked together to get the vaccine out to the public quickly and safely.
How effective are masks against the spread of the virus?
The primary route of transmission for COVID-19 is via respiratory particles, exhaled when infected people breathe, talk, cough, sneeze, or even sing.
To reduce the spread of the virus we need to reduce the probability that transmission occurs between people. This can be done by wearing a mask.
Masks help to prevent an infected person from exposing others to the droplets they are breathing out, and helps prevent another person from breathing in those infected droplets.
From scientific studies in a lab, we know that multiple layers of fabric on a mask are more effective than a single layer, able to block up to 70% of small droplets and particles coming their way. The better a mask fits around the nose and mouth, the better it performs.
Real-world studies also show that masks have been effective at reducing the spread of COVID-19 in public settings.
Why is Pfizer the only vaccine that has been approved?
How is the Novavax vaccine different?
Medsafe has granted provisional approval of three COVID-19 vaccines in New Zealand, the Pfizer, Johnson & Johnson and AstraZeneca vaccines. Currently, only the Pfizer vaccine is available.
The Novavax vaccine has not been approved by Medsafe, and is not yet approved in the US or Europe, as it’s still going through clinical trials. Vaccines safely expose your immune system to something that will help it to recognise an invader in the future.
With the Pfizer vaccine, the active ingredient is mRNA. When injected this mRNA provides information to some of your cells, so they can produce a protein similar to one found on the outside of the COVID-19 virus. Instead of injecting mRNA, Novavax vaccines inject nanoparticles covered in lab grown COVID-19 spike proteins.
These spike protein nanoparticles are then injected, using two spaced out doses similar to the Pfizer vaccine schedule.
Should pregnant or breastfeeding people get vaccinated?
Questions about vaccines and pregnancy or breastfeeding
If you have specific questions or concerns about the vaccine when pregnant or breastfeeding, have a chat to your healthcare professional.
While pregnant and breastfeeding people were not included in the initial COVID-19 vaccine trials, some of the volunteers did become pregnant during the trial with no reported adverse effects.
Since then, Pfizer has launched a separate clinical trial focussing directly on those who are pregnant. Studies show that there are no safety concerns in pregnant or breastfeeding people who receive an mRNA vaccine.
Vaccination helps mothers to produce protective COVID-19 antibodies, which might provide early protection to their newborn.
The current research indicates that it is safe for pregnant or breast feeding people to get vaccinated, and it might even provide some antibody benefits for your baby.
Does the vaccine affect fertility?
There is no scientific evidence to suggest COVID-19 vaccines affect fertility
There have been lots of studies concluding that vaccines have no effect on pregnancy or fertility.
Large population studies found no difference in the rate of accidental pregnancies, or the rates of miscarriage, in women who were vaccinated compared to those who weren’t.
COVID-19 vaccines did not affect ovarian reserve in women going under IVF, or change any sperm parameters in men, when measured before and after two doses of the vaccine.
What are the long-term effects of the vaccine?
Vaccines and long-term safety
When it comes to vaccines and long term safety, clinical trials look at the effect for six months.
This is because vaccines are a single intervention, sometimes provided over two doses that don’t remove or significantly change your biology.
Their goal is to expose your immune system to something that it can remember for next time.
Long term, the vaccine helps your immune system to have a memory of a specific pathogen like a bacteria or virus, that allows it to quickly and efficiently destroy it if ever exposed to it again.
Why is natural immunity not as effective as the vaccine?
Natural immunity fades faster and is less effective
You would think that being infected naturally with COVID-19 would give your body the best interaction with the virus to help boost your immune system.
COVID-19 is an unusual virus, and studies have shown that over one third of people who are infected with COVID-19 show no protective antibodies in their blood at all. Results also show that in general, natural immunity fades faster and is less than half as effective as immunity from vaccines.
We’ve seen this in countries like Brazil and Iran where high levels of natural immunity have sadly not prevented continuing waves of infection.
To boost your natural immune system, your body needs to train itself to recognize the virus, but this comes with the risk of you being very sick, and could lead to hospitalization, permanent organ damage, long-COVID, and even death.
The advantage of developing a strong immunity from the vaccine is that it’s more predictable than natural immunity, lasts longer and puts you at much less risk.
The overall data is clear, COVID-19 vaccines create more effective and longer-lasting immunity than natural immunity from infection.
Sources / further information
What is the safest and best time frame for immunity between the first and second shot?
The second dose solidifies your immunity
The safest and best time frame measured for immunity between the first and second dose of the Pfizer vaccine is 21 days.
This information comes from the clinical trials that measured immune response, safety and efficacy. The first dose primes your immunological memory and after it you can reduce your chances of symptomatic infection if you are infected with the virus by around 50%.
The second dose solidifies your immune memory and lowers your risk of infection by around 95%.
The longer you leave it after 3 weeks from your first dose, the more at risk you are of being infected with COVID-19 if it’s in the community as research shows that there is a sharp drop in antibody levels a few weeks after the first dose.