The global COVID-19 vaccine roll-out is providing hope of permanently moving out of the harsh restrictions that have been enforced intermittently since the COVID-19 outbreak was declared a pandemic in early 2020. However, emerging new strains of the virus such as the UK strain, the South African and the Brazilian, are triggering concerns over whether the available vaccinations will provide sufficient protection against the evolving virus.
If the vaccines prove less effective at curbing the spread of these new strains, some of which have been shown to be more easily transmitted and in the case of the UK strain potentially more deadly, then restrictions will have to be maintained. This would have a further negative impact on healthcare systems, mental health, global economies, and the treatment of and research into other serious illnesses such as cancer.
To prepare for this eventuality, scientists have been working on a universal coronavirus vaccine that will work on all current and future strains of SARS-CoV-2. The idea and ambition is that such a vaccine could work on any coronavirus, protecting the population from past and future coronaviruses.
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Why do we need to protect against new variants?
Over the course of the COVID-19 pandemic, new strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged. The problem is that the vaccines that are currently available were developed to specifically target the strain related to the initial outbreak. While the approved vaccines have demonstrated similar efficacies against some emerging strains, such as the U.K. “Kent” strain, known as B.1.1.7, they have proven less effective at protecting against others.
Currently, no discovered strains are known to render the available vaccines ineffective, but some vaccines are showing reduced effectiveness against some strains (March 2021). Research has shown that current vaccines are less effective against the South African and Brazilian variants, known as B.1.351 and B.1.1.248. Data shows that the University of Oxford and AstraZeneca vaccine is ineffective at preventing mild to moderate illness associated with infections of these variants, although the company believes the vaccine maintains its efficacy against severe cases of COVID-19.
Now, scientists have discovered a new version of the B.1.1.7 strain which has incorporated the spike protein mutation evident in the B.1.351 and B.1.1.248 variants. There is uncertainty whether vaccines will retain their efficacy on this mutation.
As current COVID-19 vaccines cannot necessarily protect against variants to the same extent as they can for the initial COVID-19 strain, there is a need for a new coronavirus vaccine that can provide universal protection against all strains. Without this coverage, there is potential for transmission to continue to accelerate, driven by new strains, forcing the world to remain under tight restrictions.
A universal SARS-CoV-2 vaccine
Currently available COVID-19 vaccines have been developed with new techniques, for example one that uses messenger RNA and another that uses modified adenovirus vectors. Both these techniques instruct the human body to produce a particular coronavirus protein to induce an immune response and prompt the body to produce antibodies that then remain in the immune system ready to fight off potential infection.
There are advantages to leveraging these new technologies in creating the currently available coronavirus vaccines; they have excellent safety profiles and they can be adapted to target a new virus incredibly quickly.
However, the current vaccines using these techniques do not produce vaccines that can provide universal protection against a virus as they target single proteins that are specific to the strain.
There are four main structural protein groups that makeup SARS-CoV-2: the S protein, N protein, M protein, and E protein. Most vaccines are focusing on the spike protein, which has been found to be mutating with different variants.
Currently, several companies are working on vaccines targeting multiple protein targets, if not all of them. Some scientists are using traditional vaccine-making techniques, those which expose the body to all the virus’s protein by exposing it to the virus itself. One of these methods introduces an inactivated virus to the body.
Many vaccines are under development, some of which show promise at being multivalent and offering protection against mutating SARS-CoV-2 strains. Companies are also working on updating current vaccines to reflect new mutations.
A universal coronavirus vaccine
Other scientists suggest that the newer developing vaccine technologies, combined with supercomputing and modeling, are the key to a universal coronavirus vaccine that is protective against all coronaviruses and not just all strains of COVID-19.
One suggested method for achieving such a vaccine is the creation of a ‘pan-virus’ vaccine which triggers the production of broadly neutralizing antibodies.
Coronaviruses have now been the cause of three outbreaks of zoonotic disease. With a universal coronavirus vaccine, the world would be prepared for any coronavirus that begins to propagate among the human population.
Many scientists believe that vaccine development is becoming necessary as a tool for being prepared rather than just as a response. A universal vaccine could prove invaluable in a world where the appearance of potential pandemic-causing diseases is thought to be becoming more frequent as a result of wildlife trade and changing animal habitats.
Could a universal coronavirus vaccine prevent future pandemics?
- Giurgea, L., Han, A. and Memoli, M., 2020. Universal coronavirus vaccines: the time to start is now. npj Vaccines, 5(1). doi: https://doi.org/10.1038/s41541-020-0198-1
- Could a universal coronavirus vaccine future-proof our response? Priya Joi. Gavi, the Vaccine Alliance. Available at: https://www.gavi.org/vaccineswork/could-universal-coronavirus-vaccine-future-proof-our-response
- Koff, W. and Berkley, S., 2021. A universal coronavirus vaccine. Science, 371(6531), pp.759-759. doi: 10.1126/science.abh0447
- The New York Times. 2021. Coronavirus Vaccine Tracker [online] Available at https://www.nytimes.com/interactive/2020/science/coronavirus-vaccine-tracker.html [Accessed 12 March 2020]