askST: How does the Novavax Covid-19 vaccine work? Can it be used as a booster?

The Novavax vaccine is a protein-based vaccine with an efficacy against mild, moderate, and severe disease of 90 per cent. PHOTO: REUTERS

SINGAPORE - The Novavax vaccine may soon be an option to protect people in Singapore against Covid-19.

The Straits Times answers some of your questions about it.

Q: What is the vaccine called?

A: More colloquially known as the Novavax vaccine or just Novavax, the technical name for the vaccine is NVX-CoV2373.

It will be manufactured in two different facilities, in Europe and India. In Europe, it will be manufactured under the name Nuvaxovid. In India, it will be manufactured under the name Covovax.

Q: Who developed the vaccine?

A: Novavax, the developer of the vaccine, is a biotechnology company based in Maryland, in the United States.

Q: Is it an mRNA vaccine? How does it work?

A: The Novavax vaccine is a protein-based, or protein-subunit, vaccine. It is not an mRNA vaccine.

mRNA vaccines use material from the virus to teach the body's cells to make copies of a protein unique to the virus, and in this manner build up resistance to it.

On the other hand, protein-based vaccines include pieces of the virus, but not the entire germ. When a person is vaccinated with them, their body realises that the protein should not be there and creates antibodies to fight it.

The Novavax vaccine teaches the body's immune system to create antibodies that fight the coronavirus' spike protein, which it uses to enter human cells.

In order to make the protein, scientists took a modified spike gene and put it into an insect virus.

The virus was allowed to infect moth cells and, when it did, the infected cells created many spike proteins.

These spike proteins were then harvested, purified, and put into nanoparticles. The nanoparticles were combined with an extract from the soapbark tree, which helps boost the immune system's response.

When the vaccine is injected into a person, the body's immune system will encounter the nanoparticles and in doing so, learn how to fight the virus.

Q: What are some other protein-based vaccines? Is this a new method of developing a vaccine?

A: Protein-based vaccines are considered a conventional approach to vaccines, and long-established vaccines against whooping cough and shingles employ this approach.

Q: How effective is Novavax against Covid-19?

A: According to the World Health Organisation, the efficacy of the vaccine against mild, moderate, and severe disease is 90 per cent.

Q: Is the vaccine likely to be available in Singapore?

A: Singapore's director of medical services, Associate Professor Kenneth Mak, said at a press conference on Wednesday (Jan 5) that he is "very optimistic" the Novavax vaccine will be authorised as part of Singapore's national vaccination programme.

Q: I heard non-mRNA vaccines cannot be used as boosters here. Will Novavax be allowed as a booster?

A: Prof Mak said that he believes Novavax's vaccine will be available as a non-mRNA alternative for the booster programme.

This is because the evidence to date shows that, compared to some other non-mRNA vaccines here, Novavax's vaccine is more effective against the Delta and Omicron variants, said Prof Mak.

But he added that the Expert Committee on Covid-19 Vaccination here will first need to complete its discussions and issue recommendations on the vaccine.

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