Latest Vaccine Order
by Jill Berensen
Australia has a new deal with another Biotech company called Novavax, a company which has never bought a vaccine to market in it's 34 year history. It claims to be able to produce 150 million doses per month from it's many production sites around the world. Our government has ordered 51 million doses which we hope will arrive at the end of this year or early 2022, after approval by the TGA (Therapeutic Goods Administration).
The Novavax vaccine is given as two doses, similar to the Pfizer and AstraZeneca shots already being used in Australia. It can be stored for up to three months at fridge temperature, which differs from the Pfizer mRNA vaccine which needs to be kept at ultra-low temperatures.
The vaccine also uses a different technology to the Pfizer and AstraZeneca vaccines. It’s a “protein subunit” vaccine; these are vaccines that introduce a part of the virus to the immune system, but don’t contain any live components of the virus.
The Novavax vaccine uses a version of the spike protein made in the lab. The spike proteins are assembled into tiny particles called “nanoparticles” which aim to resemble the structure of the coronavirus, however they cannot replicate once injected and the vaccine cannot cause you to get COVID-19.
In order for these subunit vaccines to generate strong protective responses, they need to include molecules that boost your immune system, called “adjuvants”. The goal of these adjuvants is to mimic the way the real virus would activate the immune system, to generate maximum protective immunity. Novavax includes an adjuvant based on a natural product known as saponin, an extract from the bark of the Chilean soapbark tree.
The protein approach used by Novavax was first implemented for the hepatitis B vaccine, which has now been administered for over 30 years.
Novavax’s phase 3 trials showed a 96.4 per cent efficacy against the original variant of coronavirus and 90 percent against new strains that have emerged with the protein-based vaccine. Other tests have shown Novavax offers 100 per cent protection against moderate and severe disease.
Novavax’s trial data has also shown milder side effects compared to other vaccines too. While around 40 per cent of people who receive Novavax report fatigue after the second dose, that figure rises to 65 per cent for Moderna and more than 55 per cent for Pfizer.
Trials of Novavax conducted in the US and Australia showed strong results for when given as a booster shot or third dose after two vaccinations, including a sixfold increase in antibodies against the Delta variant.
In scientific terms, after the first vaccine dose, certain cells in our immune system (normal B cells) are activated and produce a primary antibody response. After the second vaccine dose, a slightly different type of immune cells (memory B cells) mount a stronger antibody response more rapidly.
But this immune memory can wane over time. Boosters may be needed to enhance immune memory responses to the SARS-CoV-2 spike protein in people who have previously been vaccinated against COVID-19.
Boosters could also be important as new variants emerge. Vaccines can often be reformulated to protect against new viral variants when original formulations aren’t working as well.
- Trial 1 - Australia/US - 1,288 people - 600 over 60 years of age
- Trial 2 - South Africa - 4,400 people - 55.4% HIV -ve - 48.6% HIV +ve
- Trial 3 - United Kingdom - 15,000 people - 18 to 84 years old
- Trial 4 - US/Mexico - 30,000 people - 18 to 84 years old
- 25% - People over 65 years of age
- 25% - People with high risk co-morbidities
- 15% - Black/African Americans
- 10 to 20% - Hispanic/LatinX
- 1 to 2% - Native American
- 96.4% - Protection
- 86.3% - Protection against some strains
Novavax has also announced a joint Covid-19/flu shot is being developed and has reached the trial stage.
Dr Gregory Glenn, president of research and development at Novavax, said the trial was the “first of its kind” to evaluate the immune response of one vaccine against “two life-threatening diseases” at the same time.
“The combination of these two vaccines, which have individually delivered outstanding results with favourable safety and tolerability profiles, may lead to greater efficiencies for the healthcare system and achieve high levels of protection against Covid-19 and influenza with a single regimen,” he said.
The trial, which will be conducted at 12 sites in Australia, will be recruiting 640 participants over 50 years of age.