Pfizer -BioNTech Vaccine
It’s great news our vaccine roll out has started. Those receiving it first are border facing workers which is the best way to try and protect us all by reducing the risk of incursions of the virus into the community. The vaccine we have currently is the Pfizer BioNTech vaccine. Its trade name is Comirnaty and it is given in 2 doses three weeks apart. It uses new mRNA technology. The vaccine contains messenger RNA which provides the instruction code for manufacturing spike protein to our cells. After a few days the mRNA degrades. RNA vaccines do not interact with a person’s genome as our genetic material (DNA) is contained within the nucleus of our cells and mRNA cannot enter this area.
Around the world approximately 269M COVID-19 vaccination doses of a variety of different vaccines have been given since December 2 2020 in 116 countries. Amazing numbers have been given in some countries such as in the US 78.6 million doses covering 24 % of their population (by March 2), UK > 21.32 million doses covering 31 % of the population (by March 1) and Israel > 8.32 million doses covering 96 % (by March 2.) We thus have the benefit of all the real-world data on effectiveness and safety as well as initial trial data.
The Pfizer BioNTech vaccine is very effective. In the initial trial it was 95% effective at preventing laboratory confirmed symptomatic infection with the virus after 2 doses. This has been confirmed in the real world. Israel is only using this vaccine and there it has been shown to be 94% effective at preventing symptomatic COVID-19. This has been seen across age groups. This is much more effective than our annual influenza vaccinations. In countries with raging transmission and high rates of illness and deaths reducing illness has been the priority so that is what initial studies measured. However, it is important to us how much the vaccines reduce transmission. The data on how effective it is at reducing infection and thus transmission risk is still being determined but early data suggests it will be effective.
It is also safe. The vaccine commonly causes a sore arm but this is usually mild and settles in 1 or 2 days. Symptoms such as tiredness, headaches, chills, dizziness, nausea and muscle pain and even fever may also occur. These may also last a day or 2. They can be unpleasant but are helped with paracetamol and show the body is responding to the vaccine. This is why they are more common after the second dose than the first. Allergic reactions occur after any vaccine and occur at a rate of 5 per million after this vaccine. This is higher than the 1 per million rate after the influenza vaccine but still very rare. Vaccination centres are equipped to deal with it and that is why we are asked to wait a while after any vaccine. Monitoring for side effects in countries such as American has not shown any unexpected findings and there is no evidence of deaths caused by the vaccine. In New Zealand as in most countries we will be encouraged to report adverse events and they will be carefully collected and monitored. For more information about what to expect after the vaccine see : https://covid19.govt.nz/assets/resources/Vaccine-resources/COVID-19-vaccine-after-your-immunisation-v2.pdf
The vaccine can be given to people with suppressed immune systems as it is not a live vaccine. It is being given to pregnant women in Israel and elsewhere. While there isn’t trial data to recommend this there is no evidence of harm in laboratory animal studies. If someone has a high risk of catching the virus it is safer to have it than not. Because the vaccines have been given alone in trials it is recommended to have a gap of 2 weeks between this vaccine and others such as influenza. At this time, we do not know how long the vaccine will protect against COVID-19. Information about this will be gathered over coming months. The vaccine does not make someone test positive on a nasal swab test as it makes a person produce antibodies against the virus spike protein but the nasal swab looks for particles of virus.
We are in a race to protect as many people with vaccines globally before variants such as the one in Brazil (which vaccines may not be as effective against) increase and undo the gains being made. I thus recommend we take the vaccine as soon as we are offered it.