A two-part series about COVID vaccines and vaccines more broadly – Part 1
Associate Professor Priscilla Robinson is a semi-retired public health epidemiologist who has lived in Foster for many years. When she is not teaching public health and epidemiology, she occupies some of her time by serving on the South Gippsland Hospital Board.
This is a two-part series to help Mirror readers and Facebook and webpage readers – and any other interested people! – understand both about the new COVID vaccines coming to a clinic near you soon, and about the Australian Immunisation Register and vaccines more generally.
Last year everyone learned about ‘reproducibility values’, ‘flattening the curve’, and could even pronounce ‘epidemiology’. This year we will all be learning about immune responses and immunology, and some of the finer points about vaccine production.
Several people have assisted helped write these articles by reading drafts and suggesting edits. In particular I would like to acknowledge Professor Jim Buttery and Dr Phil Worboys for their inputs and attention to detail.
Part 1 – The COVID vaccines are coming – this is what you need to know
Includes information about how vaccines and medicines are approved for use in Australia, and includes a summary of the COVID19 vaccines and how they work, and what to expect as they are rolled out.
Part 2 – Its generally complicated – what you need to know about all of those ‘little pricks’
The main ways in which germa make people sick and how the vaccines to protect us from them are made, and about the systems we use to keep track of the vaccines we have had and how public health specialists monitor infectious diseases.
Part 1 – The COVID vaccines are coming – this is what you need to know
This week’s article includes information about how vaccines and medicines are approved for use in Australia, and includes a summary of the COVID19 vaccines and how they work, and what to expect as they are rolled out.
One year on since the beginning of the COVID19 pandemic and we are on the verge of having vaccines offered to us, an astonishing scientific achievement.
In Australia, the evaluation of medicines and vaccines for public use is overseen by two committees.
Firstly all new vaccines have to be evaluated by a national committee of experts, ATAGI – the Australian Technical Advisory Group on Immunisation. You can read about their work at (https://www.health.gov.au/committees-and-groups/australian-technical-advisory-group-on-immunisation-atagi).
Secondly, medicines (including vaccines) and medical appliances are reviewed, approved, and rules for their use established by the Therapeutic Goods Administration (the TGA) committees. (https://www.tga.gov.au). They are responsible for the evaluation and regulation of ‘…therapeutic goods including prescription medicines, vaccines, sunscreens, vitamins and minerals, medical devices, blood and blood products’ – that is, anything to do with the medicines and medical appliances we might use.
Microorganisms (germs) are living things, and like all living things they exist to survive to produce their own next generation. There are thousands and thousands of microorganisms, but only some cause illness in humans. Most microorganisms have an ‘environmental niche’ – a preferred and convenient place to live – much like humans really. The preferred home for SARS CoV-2, the microorganism which causes COVID19, is the human respiratory tract.
Your body has a clever response mechanism which recognises some germs as something that can make you ill (an ‘antigen’) and makes an immune response to it (‘antibodies’). Vaccines work by giving a tiny dose, or sometimes just a small part of the germ. Your own immune protection has a memory back-up system, and if you come across the same germ again it quickly sets about protecting your body from it.
Traditional testing of vaccines involves a lengthy and very careful set of a minimum of three clinical trials. Firstly, it is given to a small group of healthy adults, to make sure it does not cause illness and that the vaccine recipient makes protective antibodies. The second phase is designed to clarify things like appropriate doses, to make sure that it prevents disease and again that it is safe. The third phase, again is in healthy adults but usually excluding groups such as pregnant women, and is designed to make sure it works in large populations.
A fourth phase is conducted after the vaccine has been introduced, collecting safety and effectiveness information during widespread use in whole populations, and the only people who are not included are people with specific reasons for not being immunised. Sometimes phases three and four are merged. This American website for the Centres for Disease Control (https://www.cdc.gov/vaccines/basics/test-approve.html) has some great information about vaccine development and trials, although for the exact approval process in Australia see the Australian websites above.
This brings us to COVID vaccines, which have been developed in vaccine terms at breakneck speed. Usually using words like ‘breakneck’ and ‘vaccine’ in the same sentence causes concern amongst many people, so let’s try to unpack what has happened over these twelve months in vaccine land.
One fascinating thing about the new vaccines is that vaccine researchers are using quite new technologies, although these technologies have been successfully used for other specialised drugs well before SARS-CoV-2 arrived. Whilst we have heard a lot about a few of these vaccines, there are actually more than 600 in various stages of production. However, only a few are ready to roll out, and at the time of writing only three are likely to be available for use in Australia any time soon. The COVID vaccines are all designed to protect us from the SARS CoV-2 germ. The first to be licensed in Australia are called mRNA vaccines (mRNA stands for messenger ribonucleuc acid). Many people are nervous about these new vaccines, because fairly new technologies are being used to make them, and a number of myths are already circulating about the possible harms they can do. It is therefore very important to understand that as none of these vaccines can get into your own DNA it cannot change your own genetic code, and will not affect fertility. The mRNA fragments in the vaccine do not last long enough in your body to cause or add to autoimmune problems.
These vaccines work by getting our cells to read the mRNA genetic information from the virus, make the protective antibody for the spike protein so that our own immune system knows how to respond, and then destroy the mRNA. The mRNA is never incorporated into our own human genes. The effective immune response to it allows us to fight off any future infection with that specific organism, in this case SARS CoV-2. The other vaccines likely to be introduced in Australia use different technologies, but all use the spike protein (you have all seen the spikes on the pictures of the COVID19 virus on almost every newsreel last year) to allow our own immune systems to make a protective antibody response to it. Importantly, these are questions which the ATAGI and TGA committees have thought about long and hard, and have read the scientific evidence in great detail, and have concluded that these vaccines are safe.
Most COVID-19 vaccines will need 2 doses to work properly. Although people will make a good immune response a couple of weeks after the first dose, the second dose is important for a complete antibody response. Therefore once the vaccination programme begins we will all be given two doses of the COVID vaccine about three weeks apart. Importantly, the antibody response produced by most COVID-19 vaccines is greater than that induced by natural SARS-CoV-2 infection.
Because the vaccines are so new, we do not yet know how they work if given at the same time as other vaccines, such as influenza vaccine, so other vaccines such as flu will be given at different appointments in 2021. Information about whether future boosters of COVID-19 vaccines will become available as our ATAGI and AVC committees review evidence over the next few years.
Lastly, remember that once upon a time each approach to making a vaccine was new. As with previous vaccine developments, these new vaccines are likely to change the way vaccines are made in the future, and this will probably just be the first of many vaccines made this way.