Top 3 COVID-19 vaccine questions – extra vaccine dose, vaccine effectiveness, and treatment for COVID-19

Dr Lucas de Toca, COVID-19 Primary Care Response First Assistant Secretary, answers the top three questions you’ve been asking on our social accounts.

Date published:
General public

Good morning, I am Dr Lucas De Toca and I lead the rollout of the vaccine through GPs, Aboriginal health services and pharmacies for the Australian Government. Today we are going to be answering some of the most commonly asked questions you have asked in our social media channels. As usual I am joined by Linda, who is going to be doing Auslan interpreting. We're on the land of the Ngunnawal people, so Dhawra nhuna, dhawra Ngunawal. Yanggu gulanyin ngalawiri, dhunayi, Ngunawal dhawra. Wanggarralijinyin mariny balan bugarabang. I also acknowledge the Traditional Owners of the lands where you may be watching from. Today we're going to talk about a third dose for immunocompromised people, we're going to talk about how does the vaccine actually protect from severe illness, and we're going to talk about how people who are COVID positive get treated and what advice they get. Before starting, I want to shout out the thousands of people across Australia that are still coming to get tested. It's really important that we continue to get tested, even if we have the mildest of symptoms, because that is the only way to get on top of the virus, especially as parts of the country are commencing to open up like NSW this week. Congratulations to everyone in Sydney who is enjoying expanded freedoms now that they have opened up.

First, let's talk about what the advice that was published last week about people getting a third dose if you are immunocompromised. What does that mean and why is that necessary?

The Australian Technical Advisory Group on Immunisation, also known as ATAGI, has provided advice to Government that, in some cases, a small number of people may require a third dose as part of their primary vaccination course, as part of their normal vaccination process, in order to achieve similar protection that people who are not immunocompromised. As you know, the vaccines work by teaching our immune system what the virus looks like and how the virus particles look so that the immune system can mount a response and be ready to neutralise the invader if they get in touch with the real thing. If your immune system is weakened, the ability of your system to then respond to the vaccine and mount an immune response is also weakened. The vaccines are absolutely safe for people who are immunocompromised because they do not contain live virus, there is no risk of getting the disease from the vaccine, because there is no live virus to trigger it.  However, because people who are very severely immunocompromised may not mount as strong a response as people who have a not compromised immune system, ATAGI has recommended that people get a third dose because the first one allows your immune system to recognise the virus, the second one reinforces it, and if your immune system is weakened, a third one may help build up the same level of immune protection that people who are not immunocompromised get. This only applies to a small number of people who are severely immunocompromised: people with blood cancers, or people with active cancers that are being treated with chemotherapy or radiotherapy, people who are on high levels of immunosuppressant drugs, or have a condition that means their immune system is weakened. This does not mean anyone who is using any kind of drug that might impact their immune system or people with chronic disease in general, it is just a small number of people who are severely immunocompromised because of treatment or disease. Information has gone out to all providers, so the GPs that are administering the vaccine, to the pharmacists, to the other specialists, informing of what conditions may require a third dose of vaccine. So talk to your regular health provider to discuss whether you need a third dose or not, noting that as I said, it is a small minority of people, it is not everyone with a chronic disease, it is only those who are severely immunocompromised. It is still unclear whether even with three doses, people who have a really weakened immune system can still mount the same amount of protection as people who don't have a weakened immune system from the vaccine. So it's really important that even after your third dose, you continue to practice COVIDSafe behaviours if you are severely immunocompromised, to make sure that you stay protected and you reduce your chances of getting the virus. But it is good to give it a go and there is indication that for some of those people, they might develop the same response after that third dose.

We talk about the importance of having the vaccines and we talk about the importance of completing the course, but how does the vaccine work in preventing severe disease, hospitalisation and death?

Any vaccine works by teaching your immune system, teaching your body, what the virus looks like so that when they get in contact with the real thing, they are already ready to fight it, they already have the tools that are required to address it. In order to do so, the vaccines that we have, the AstraZeneca vaccine, the Pfizer and the Moderna vaccine, that don't contain live viruses, show your body bits of the actual virus so that they can recognise that aspect. In the case of SARS-CoV-2, the virus that causes COVID-19, we talk about the spike protein. What is a spike protein? You will have seen images, a drawing impression of what a coronavirus looks like because they are everywhere throughout the pandemic and you will have seen that they are often depicted as a circle with little spikes around it. In fact, the word 'Corona' in Latin and many Latin-derived languages like Spanish, means ‘crown’ and coronaviruses are called ‘coronaviruses’ because they look like they have a crown because of the spikes around their circumference. That spike protein is what allows the virus to then get in touch with a cell and then insert the raw material to replicate and cause an infection, but the spike protein itself, detached from the virus, cannot cause the disease. So the vaccines we have allow your body to create a spike protein that your immune system can recognise and prepare a response to it. The immune system has several ways in which they protect you and they are all interlocked and support each other. They can generate antibodies which are really small particles that attach to the virus and help your immune system fight it, or even directly neutralise it. They also have cellular responses, so white blood cells that support the response and that actually survive for months and years after receiving a vaccine. So by making your body familiar with the coronavirus, the SARS- CoV-2 spike protein, by the time you get in  contact with the actual virus, your body has the tools required to fight it. That means for the majority of people, in fact 10 times more likely than unvaccinated people, the infection is very mild if you get infected at all, because your body is already ready to fight it, it is neutralised, you get a lower amount of virus in your body, you get a lower reaction to it because it is neutralised quicker and your course of infection is milder and shorter, so you have lower chances of getting the disease. You can still get it, it is not a magic shield, you can still get infected but at a much lower chance, and if you are infected you have 10 times lower chances of getting severe disease from it because your body is already ready to fight. It is using your natural immunity, using the immunity in your body, but giving them an advance warning, giving them a heads up of what the virus looks like so that the moment it arrives, it can be fought.

Finally, what if you still get an infection from COVID-19 but you are unvaccinated and you get the virus? What happens? How do we treat COVID?

In the majority of people, and it is closely related to age, COVID can have a mild course. People can be asymptomatic or have minimum symptoms. They can have shortness of breath, fatigue, loss of taste or smell, cough, fever. People who have low risk factors, who are younger, and who have a very mild symptomatic disease, are often sent home to isolate and monitor their symptoms, and continue with their infection for the duration of it, for the 1-2 weeks where that happens at home. It's really important that people keep isolated, keep to themselves, make sure they are hydrated, that they are eating well, and they are monitoring their symptoms. They will be contacted, and different states have different arrangements, by health providers from the public health unit or by their GP to look at how they are feeling, and if there is a deterioration, like the symptoms get worse, they have difficulty breathing or they have a very high fever, or even in the early stages of the disease, people who have high risk factors, older people or people with underlying conditions that means that their chances of severe disease are higher, might be hospitalised. People in hospital then can be monitored, they can be given fluid replacements if they are dehydrated or have issues with food intake, and they can be treated with antibiotics because sometimes what happens with COVID is that you develop pneumonia on top of the COVID infection. If people still deteriorate and have trouble breathing or they have severe disease, multiorgan failure, or advanced pneumonia, they may be moved to the intensive care unit where they may or may not receive additional oxygen or additional ventilation support. Those are the cases that are very severe. COVID is different from other diseases because the majority of people in the ICU only spend a few days in ICU, people with COVID can spend weeks in the intensive care unit which means they are at risk and they are in the severe stages of the disease for quite a long time. It also means this has an impact on the intensive care unit capacity because COVID patients tend to stay there for longer than other people who need to go to the ICU like victims of car accidents or other crashes. There is a whole spectrum of severity with COVID-19, and there are some things that we know increase your likelihood of being very sick: the older you are, the higher chances. The more underlying conditions that you have, the higher the chances to get severe disease. But ultimately, it's a gamble you don't want to have because even young, healthy, strong, very fit people can get severe disease from COVID-19. So it is not worth taking the risk and the best way that we can prevent that, minimise our chances as much as possible from getting severe disease from COVID, is by getting the vaccine. Most people in Australia have now got one. If you still haven't, please consider talking to your health professional and making a vaccine appointment as soon as possible because it is the only way you can very confidently minimise your chance of severe infection. Of course, continue to practice COVIDSafe behaviours, wash your hands regularly, and if you have the mildest symptoms, get tested, and that will also minimise your chance of getting infected altogether.

That was a long one, thank you for staying on if you did. Thank you for continuing to practice COVIDSafe behaviours and coming forward to get vaccinated. We’ll tune into the next one and thank you for sending in your questions. Have a great day.

Top 3 questions

  1. What are the conditions that mean some people need an extra dose of the COVID-19 vaccine? Why do they need this?
  2. Can you explain how the COVID-19 vaccine is able to protect people against serious illness?
  3. How are people cared for/treated if they get COVID-19?

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