What you need to know about COVID-19 vaccines By Talley, Sorger, Magarry, Recsei

Most of us have felt information overload during the COVID-19 pandemic. Keeping track of changing data, restrictions and health advice can be overwhelming.
These FAQs provide clear, evidence-based advice to help you make choices about COVID-19 vaccines for yourself and those you care for. We recommend speaking with your General Practitioner to gain medical advice about your personal situation.

How can I know these vaccines are safe and effective when they are new and were developed so quickly?
COVID-19 vaccines were developed quickly compared to some other vaccines and medicines. This was made possible by teams around the world working hard from very early on in the pandemic to make COVID-19 vaccines.
There was already a lot of research into previous coronaviruses such as SARS in 2002 and MERS in 2012. So, researchers had a great head start.
The technology COVID-19 vaccines are based on has been around since the 1970s. Both mRNA vaccines (like Pfizer and Moderna) and viral vector vaccines (like AstraZeneca) have been researched over the past decade.
Short term side effects
The vaccines were tested thoroughly in laboratories, then in trials with thousands of people. Now, billions of people globally have been vaccinated against COVID-19 with very few serious side effects reported.
There is still a small risk of side-effect, as is the case in any medicine.
The global community works together to watch out for side effects and to take action in response. A very rare but serious blood clotting problem (thrombosis in combination with thrombocytopenia) was identified and in response, authorities changed advice on who should receive the AstraZeneca vaccine.
It was also quickly noticed that there is a very low risk of inflammation of the heart muscle (myocarditis) or the lining of the heart (pericarditis) with mRNA vaccines. In most cases this problem causes no serious health issues and people recover fully.
Long term side effects
We can’t see into the future, but there is no reason for the COVID-19 vaccines to have any long-term side effects. The immune response that they produce in our bodies is the same as if we actually got COVID-19.
No part of these vaccines stays in our bodies. The mRNA in Pfizer and Moderna vaccines is broken apart by our cells within a few days. The viral vector in AstraZeneca vaccines lasts a little longer, but only a few weeks. Overall, the risk from COVID-19 outweighs the small risks from the COVID-19 vaccine.
Comparing risks
Comparing the risks from being vaccinated versus not being vaccinated may also help you make your decision.
Under 50-year-olds are at the most risk of the clotting problem after getting the AstraZeneca vaccine. This happens in approximately 3.1 out of 100,000 people in this age group. In comparison, the risk of a 40-year-old woman who hasn’t been vaccinated dying of COVID-19 is 63 out of 100,000.
Men under 30 years of age are the most at risk of heart inflammation after getting the Pfizer or Moderna vaccine. There have been a few hundred cases in Australia. These have been serious enough to require hospitalisation, but most patients have recovered well.
Importantly, myocarditis is much more common in people who get COVID-19 compared with people who are vaccinated.
If the vaccine is effective, why can vaccinated people still get COVID-19 and spread the virus?
The virus that causes COVID-19 can still enter our bodies even if we are vaccinated. The difference is that if you are vaccinated, your immune system will be ready to fight the virus straight away. This means that you probably won’t get sick, or your illness will be mild.
While our immune system is fighting the virus, we still have it in our bodies and can spread it to other people, even if we are vaccinated.
The difference is that if we are vaccinated, we are much less likely to spread the virus to others.
What is the risk of viral “shedding” after COVID-19 vaccination?
We can release or “shed” a virus when we are infected with it. For example, COVID-19 being released and spread through a cough or a sneeze.
COVID-19 vaccines don’t contain any live, whole viruses. None. So, if we are vaccinated, we can’t “shed” the virus and infect another person. It’s impossible! We also can’t spread any part of the vaccine to another person because it is broken down by our bodies so quickly.
I am breastfeeding, pregnant or want to become pregnant. Will these vaccines affect my fertility/my baby?
The Pfizer and Moderna vaccines are recommended if you are breastfeeding, pregnant, or planning pregnancy.
Evidence from around the world has shown that Pfizer and Moderna vaccines are safe if you are trying to conceive, pregnant and breastfeeding. There is no evidence of lowered fertility after getting the vaccine. There is also no evidence of increased risk of miscarriage or your baby developing abnormally. Getting vaccinated protects you and your baby.
If you are pregnant, you have a higher risk of getting very seriously ill if you get COVID-19. Your baby may also have a higher risk of being born prematurely.
You can consider the AstraZeneca vaccine if you cannot access Pfizer or Moderna, and if the benefits outweigh the risks for you. Your doctor can help you make this decision.
There is no evidence of vaccination causing male infertility.
How can I know that adverse events and deaths aren’t being hidden or underreported?
Some media might be hesitant to report on adverse events (negative reactions to vaccines), fearing that this will make people afraid of being vaccinated.
However, monitoring adverse events is extremely important and is taken very seriously in Australia. The Therapeutic Goods Administration (TGA) investigates all reports of serious side effects. They also keep a record of all reports of adverse events so they can pick up patterns.
Health professionals report adverse events in their patients to the TGA or their local health authority.
Consumers can also report adverse events:
● To the TGA using the National Adverse Event Following Immunisation (AEFI) reporting form or the Report a Side Effect of a Medicine form
● By calling NPS Medicinewise on 1300 134 237 and speaking to a pharmacist can lodge the report and provide further advice
● To their state or territory health service
Most reactions to vaccines are mild and expected, like aching in your arm or a mild fever. These don’t need to be reported unless they don’t go away or get worse.
Importantly, health problems experienced after getting vaccinated are not always related to the vaccine. As we report and investigate these problems, we can be more confident in vaccines and other medicines we take.
Why should I get vaccinated? If enough other people do, won’t we have herd immunity?
Herd immunity happens when enough people in a group are immune to a disease, so it has very few “hosts” and can’t spread.
There are a few reasons why achieving herd immunity for COVID-19 might not be possible:
● People with immunity can still have the virus in their body and spread it
● Immunity can fade over time (especially for people who had COVID-19) and reinfection is a risk
● Vaccination rates aren’t high enough in some places
● New variants behave differently
This means you are more likely to be protected by being vaccinated than by relying on herd immunity.
Can I be forced to get vaccinated?
Vaccination for COVID-19 is voluntary as are all vaccinations in Australia and people have the option to choose. However, there may be circumstances in the future where proof of vaccination will be required such as for border or re-entry requirements, or continued employment in particular areas.
From 17 September 2021 Australia introduced the mandatory vaccination requirement for all residential aged care workers in line with relevant state and territory directions.
Can I get a medical exemption for the vaccine for employment or travel purposes?
In almost all cases, no. There are extremely few medical reasons you cannot get vaccinated.
The only indication to receive an exemption is anaphylaxis (life-threatening allergic reaction) to the stabilising chemical components in the vaccine. This is a very uncommon allergy. Talk to your doctor if you are worried.
Useful Websites
If you wish to find out more about COVID-19 there are several websites which contain expert advice and guidance, but it is important to talk to your General Practitioner who can assist you with medical advice specific to you and your health care requirements.
Australian Department of Health
ACT Health
NSW Health
NT Health
QLD Health
SA Health
TAS Health
Vic Health
WA Health


Distinguished Laureate Professor Nicholas J. Talley, AC, MBBS (Hons.)(NSW), MD (NSW), PhD (Syd), MMedSci (Clin Epi)(Newc.), FRACP, FAFPHM, FAHMS, FRCP (Lond. & Edin.), FACP, MACG, AGAF, FAMS, FRCPI (Hon)
University of Newcastle, Australia
Editor-in-Chief, Medical Journal of Australia

Chief Medical Officer, Integral Diagnostics

Ms Angela Magarry RN (RPAH former), CGFNS, BHA, MPS (UNSW), FCHSM, CHE
Chief Executive for the Council of Presidents of Medical Colleges (CPMC)

Ms Krista Recsei Master Health Communications (USyd)
Policy and Communications Manager, Council of Presidents of Medical Colleges (CPMC)