Immunisation against COVID-19 will soon be compulsory 

5 November 2021

By Rod Jackson, Professor of Epidemiology, University of Auckland

Originally published in the NZ Herald on 3 November 2021

Now that New Zealand has all but abandoned the elimination strategy for COVID-19, kiwis can either choose to be voluntarily immunised by the Pfizer vaccine or compulsorily immunised by delta.

The delta variant of COVID-19 is so infectious that herd immunity, where a largely vaccinated population will protect the minority of unvaccinated people, does not work until about 98% of the population is vaccinated. Delta doesn’t listen to the ‘my body my choice’ mantra of the unvaccinated and ironically, only those who choose the vaccine will have any choice of how and when they will get immunised.

Getting immunised by the virus is the hard way to do it. Like all viruses, COVID-19 is a message on how to make copies of itself, made up of letters from the genetic alphabet, wrapped in a protein skin covered in spikes. The COVID-19 virus will attach to billions of cells all over the body, wherever cells have docking stations that are the perfect fit for the spikes on the virus surface. These cellular docking stations are found in the lungs, brain, heart, gut, blood vessels, ovaries, uterus, testes, and elsewhere. Once the virus attaches to a cell’s docking station, it injects a self-replicating 40,000 letter genetic message into the cell which is an instruction manual on how to make multiple copies of itself. It hijacks the cell’s factories to make these new virus copies, and makes the cell sick by stopping the production of the proteins required to keep a cell functioning properly. New copies of the virus leave the cell and repeat the process all over the body. The virus can stay around for weeks, causing death, disease and long COVID. People infected with delta will also infect many others and possibly cause their death, disease or long COVID.

In contrast, getting immunised by the Pfizer vaccine is the easy way to do it. The vaccine is a short, non-replicating 4,000 letter genetic message wrapped in a envelope of fat. Its more like an instruction ‘brochure’ than the virus instruction ‘manual’ because all it does is describe how to make a couple of hundred copies of a small section of the virus spikes. A vaccine particle is extremely fragile and cannot actively enter cells like the virus does. It is only taken up by one type of cell, which are defender cells in the body’s immune system. The vaccine seldom travels beyond the defender cells in the arm in which the vaccine is injected. Once inside a defender cell, the vaccine gives the cell’s factories an instruction to make a couple of hundred copies of a small section of the virus spikes, before breaking up. Most of the Pfizer vaccine is gone in hours and is all gone in a couple of days. The vaccine message cannot replicate itself, so cannot change a person’s DNA. The spike sections made by the cell using the vaccine instructions, move to the surface of the defender cells where they teach the body’s immune system to recognise the spikes on the COVID-19 virus surface as foreign. The spike sections themselves are completely harmless and are broken up by the body’s immune system within a couple of weeks. Moreover, unlike being immunised by the virus, the vaccine is not a virus, so cannot cause a Covid-19 infection.

When a vaccinated person is subsequently exposed to the virus, their immune system is immediately able to recognise the virus as foreign and start fighting it, which dramatically reduces the risk that the virus will spread and cause severe disease or death. In contrast, an unvaccinated person’s immune system does not immediately recognise the virus as foreign and it takes much longer to recognise the virus and start fighting back This time delay is what allows the virus to spread all over the bodies of many unvaccinated people and can cause death, disease and long COVID.

New Zealand is currently in a race against time to get as many people immunised with the world’s most evaluated and safest COVID-19 vaccine. The alternative is the equivalent of compulsory immunisation by a virus that has already killed over 11 million people and has overwhelmed health services and destroyed peoples livelihoods worldwide. The effectiveness of COVID-19 vaccines in preventing severe disease and death is a modern miracle. Tragically, the majority of eligible New Zealanders who have still not been vaccinated are our most unwell and our most socially and economically deprived citizens, among whom Māori are hugely over-represented. I have supported widespread public health restrictions and vaccine mandates, not because they are right or wrong, but because COVID-19 is a matter of life or death.