WEHI researchers are studying 'nanobodies' - unique antibodies produced by alpacas - in a bid to understand whether they might be effective in blocking SARS-CoV-2, the virus that causes COVID-19. 

FAQs

• What are antibody-based therapies?

• Why do we need antibody-based therapies for COVID-19?

• What is the difference between an antibody based therapy and an anti-viral treatment?

• What is the difference between an antibody-based therapy and a vaccine?

• What are nanobodies?

• How do nanobodies help in the development of treatments for COVID-19?

• Can alpaca nanobodies be used to treat COVID-19 infection in humans?

• How long will it take for this treatment to be used in humans?

• Are the alpacas infected with COVID-19?

• Do the alpacas pose a COVID-19 risk to humans, livestock or native animals?

• Who else is involved in this research consortium?

What are antibody-based therapies?

Antibody-based therapies, sometimes called ‘biologics’, are medicines that mimic antibodies – naturally occurring immune proteins – to fight infection. Antibody-based therapies are already in clinical use for diseases such as cancer and inflammatory and autoimmune conditions, including rheumatoid arthritis.

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Why do we need antibody-based therapies for COVID-19?

Antibody-based therapies can be used both to prevent and treat COVID-19. They are particularly useful in older people or those who are immunocompromised and may not be able to mount a robust immune response to a vaccine.

While antibody-based therapies could be very effective in treating or preventing COVID-19 infection, they are only effective while the therapy is being administered and for a short time after therapy ceases and would not provide long-term protection, as something like a vaccine could.

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What is the difference between an antibody-based therapy and an anti-viral treatment?

Antibody-based therapies can be used for treating a number of diseases, not just viral infections. Antibody-based therapies that are used to prevent or treat virus infections are one type of anti-viral treatment.

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What is the difference between an antibody-based therapy and a vaccine?

Vaccines elicit an immune response in humans to produce antibodies, whereas antibody-based therapies deliver the effective antibodies directly.

Vaccines are often able to provide long-term protection, while antibody-based therapies only offer protection while the therapy is administered, and for a short time after it ceases.

Both vaccines and antibody-based therapies (and other potential treatments) would prove useful in the ongoing response to the COVID-19 pandemic.

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What are nanobodies?

Members of the camelid family (alpacas, llamas, camels) make unique antibodies – nanobodies – that are smaller than conventional antibodies.

Conventional antibodies are composed of two immunoglobin – heavy chains and light chains – whereas alpacas make the majority of antibodies that lack the light chains. Nanobodies are laboratory-made antibody fragments of the heavy chain only domain that recognizes foreign proteins.  Nanobodies are excellent for the investigation of novel anti-viral therapies because they are highly specific and stable.

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How do nanobodies help in the development of treatments for COVID-19?

In this research, alpacas are immunised with a non-infectious ‘replica’ of the spike protein that is found on the surface of the SARS-CoV-2 virus (the virus that causes COVID-19) to produce antibodies. Our researchers extract the gene sequences encoding the nanobodies and use this to produce millions of types of nanobodies in the laboratory to select for the ones that bind to spike protein. They test the effectiveness of each nanobody to find those that are most effective in preventing or inhibiting the virus from entering cells. The ‘best’ nanobodies undergo further testing to evaluate their suitability for development into an antibody-based therapy that could safely and effectively be used in humans.

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Can alpaca nanobodies be used to treat COVID-19 infection in humans?

No. However, once we know which nanobodies are the most potent in blocking the virus, we can use this information to develop next-generation nanobodies that mimic human antibodies to develop antibody-based therapies that could safely and effectively be used in humans in the future.

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How long will it take for this treatment to be used in humans?

We are in the early stages of this research. There are a number of steps that need to take place, including clinical trials, before this antibody-based therapy could be used in humans. However, we are hopeful antibody-based therapies could offer one potential solution to COVID-19 and could be used alongside other treatment methods to combat this global pandemic.

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Are the alpacas infected with COVID-19?

No.

The research team are not immunising the alpacas with SARS-CoV-2, which is the infectious virus that causes COVID-19. The alpacas are immunised with a synthetic and non-infectious version of the ‘spike’ protein that is found on the surface of the coronavirus. This synthetic ‘spike’ protein does not come from the virus itself, so is not capable of causing COVID-19 infection or disease in the alpacas.

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Do the alpacas pose a COVID-19 risk to humans, livestock or native animals?

The alpacas pose absolutely no COVID-19 risk to humans or other livestock. They are not infected with the virus that causes COVID-19, or any part of the virus that causes COVID-19, and therefore it is not possible for them to infect humans, livestock or other animals with the disease.

As with all our research, health and safety is paramount and we abide by all relevant safety regulations at both a state and federal level. All Institute research involving animals complies with strict guidelines and legislation to protect the welfare of animals and ensure that animals are cared for in an ethical and humane way.

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Who else is involved in this research consortium?

The research program brings together the expertise of Victorian and Australian academic and industry leaders in infectious diseases and antibody therapeutics, at the Walter and Eliza Hall Institute, the Doherty Institute, CSL, Affinity Bio, CSIRO, the Burnet Institute and the Kirby Institute.

The research has been funded by the Medical Research Future Fund and the Victorian Government.

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