1. Will we need to update vaccines to deal with the Omicron variant?
The Omicron variant contains a new pattern of mutations to its spike protein. These changes could disrupt the ability of some – but probably not all – of the antibodies induced by the current vaccines.
Coronaviruses use spike proteins to attach to ACE-2 receptors on the surface of human cells and infect them. All mRNA COVID-19 vaccines work by giving instructions in the form of mRNA that direct cells to make a harmless version of the spike protein.
This then induces the human body to produce antibodies.
2. What would be the expected regimen for these new vaccines?
Existing mRNA vaccines, like those made by Moderna or Pfizer, code for a spike protein from the original strain of coronavirus. In a new or updated vaccine, the mRNA instructions would encode for the Omicron spike protein.
People already vaccinated or previously exposed to COVID-19 would likely need only a single booster dose of a new vaccine to be protected not only from the new strain but also other strains that may be still in circulation.
If Omicron emerges as the dominant strain over delta, then those who are unvaccinated would only need to receive 2-3 doses of the updated vaccine. If delta and Omicron are both in circulation, people would likely get a combination of the current and updated vaccines.
3. How long until a new vaccine might be ready?
It takes only three days to generate the DNA template needed to make a new mRNA vaccine.
Then it would take about a week to produce sufficient doses of the mRNA vaccine for testing in the lab and another six weeks to perform the pre-clinical tests on human cells in test tubes to make sure a new vaccine works as it should.
So within 52 days, scientists could have an updated mRNA vaccine ready to plug into the manufacturing process and begin producing doses for a human clinical trial.
That trial would likely require at least another few weeks for a total of around 100 days to update and test a new vaccine.
While that trial is going on, manufacturers could start switching their current process to making a new vaccine.
Ideally, once the clinical trial is complete – and if the vaccine gets authorized or approved – a company could immediately start rolling out doses of a new vaccine.