No COVID-19 vaccines have been created using live viruses, nor can you catch or shed COVID-19 after vaccination. All three COVID-19 vaccines available in Australia have been shown to be effective and safe.
Moderna: The Moderna vaccine is a messenger RNA (mRNA) vaccine. This is a different way of developing vaccines; conventional vaccines are often produced using either fragments or weakened forms of the virus, but mRNA vaccines use only parts of the virus’s genetic code. mRNA acts as a set of instructions, and tells your body how to produce fragments of the COVID-19 virus known as spike proteins. When the spike proteins are produced from mRNA ‘instructions’, the proteins are then ‘displayed’ on the surface of some cells in your body. Your immune system recognises these proteins as being foreign, and starts preparing its own defences known as antibodies to fight coronavirus. You will need two doses 4 weeks apart, although this can be reduced to 14 days at an absolute minimum.
When spike proteins are produced by your body and displayed on the surface of cells, it creates a stronger immune reaction and better protection than conventional vaccines.
mRNA vaccines such as Moderna have been shown to be safe and effective for pregnant and breastfeeding women, and can be given to eligible people over 12 years of age.
The Moderna mRNA vaccine must be stored at ultra-cold temperatures (-15°C to -25°C), however can be stored for up to one month at normal refrigerated conditions. The Moderna vaccine is being manufactured in the United States, Switzerland and Spain.
Pfizer: The Pfizer vaccine is an mRNA vaccine, and almost mirrors the Moderna vaccine in how it works and in effectiveness. It has also been shown to be safe and effective for pregnant and breastfeeding women, and can also be given to eligible people over 12 years of age.
The Pfizer mRNA vaccine must be stored at ultra-cold temperatures (-70°C), however can be stored for up to one month at normal refrigerated conditions. The Pfizer vaccine is being manufactured in the United States, Belgium and Germany
The AstraZeneca vaccine was developed by the University of Oxford and pharmaceutical company AstraZeneca. It is not an mRNA vaccine; instead, it uses a virus harmless to humans to deliver the virus’ genetic code, for the body to respond by creating antigens in a similar way to the Pfizer/BioNtech vaccine. Recipients require two doses administered between 4 and 12 weeks apart. It can be stored and transported at normal refrigerated conditions between 2°C and 8°C. The AstraZeneca vaccine is currently manufactured by Australian-headquartered pharmaceutical company CSL.
Whilst the AstraZeneca vaccine can be used in eligible people over 18 years of age, mRNA vaccines such as Moderna or Pfizer are preferred for people under 60 years of age. This is due to an extremely rare, but still present, risk of a particular type of blood clot in younger people. Whilst the risk of a catastrophic event from the AstraZeneca vaccine is extremely low – less than 1 in 1 million, or roughly the same risk as being struck by lightning – mRNA vaccines do not carry any risk at all of blood clots and are therefore preferred in people under 60 years of age.