Dr.
Omicron became the dominant variant in
Studies suggest two doses of the existing mRNA vaccines from Pfizer-BioNTech and
Multiple studies, however, suggest the vaccines are excellent at keeping symptoms mild, preventing hospitalizations, and shortening the stay and lowering the level of care for those
Both
But Sharma said even with the expedited review process for vaccine variants, that's "probably not" fast enough.
"By that time, based on what we've known about the Omicron wave, it might well and truly be through," she said. "And then the question is always, 'is there another variant that's coming up?'"
The solution, she said, likely lies with vaccines that can target more than one variant at a time.
The COVID-19 vaccine technical committee of the
Booster shots that heighten antibody development became the immediate response to Omicron for many governments, including
Dr.
"Boosting your way out of a pandemic is going to inevitably shoot you in the foot in the sense that you're going to have a future variant that's going to emerge that's going to cause problems," he said. "It's going to evade your vaccines, and then you're going to have to scramble."
Omicron doesn't evade the existing vaccines entirely but a future variant could, he said. The issue largely stems from the fact that the original vaccines train the body's immune system to recognize what is called the spike protein found on the surface of a virus, and that spike protein is mutating significantly.
Think of the mutated spike protein as a bit of a disguise that makes it harder for the immune system to recognize the virus and mount a defence to kill it off.
Omicron has more than 50 mutations, and at least 36 are on the spike protein.
Multivalent vaccines that use the spike protein from more than one variant, or that target the genetic components of a virus rather than the spike protein, are possibly the ones that could offer protection for both this pandemic and the next novel coronavirus that emerges.
"It's pan-coronavirus, where it's looking at big broad neutralizing responses and you don't have to update it every season and so on," said Murthy. "That's been the Holy Grail of flu vaccinology for the past number of decades. We haven't achieved that yet, because flu is a bit tricky, but we think that it's achievable for coronavirus, specifically."
The
Sharma said even if the vaccines aren't working as well against variants as they were against the original virus, to her "they're still miraculous."
"To have a vaccine that was developed that quickly, that still has, through multiple variants … with boosters, up to 70, 80 per cent effectiveness against serious disease, ailments, hospitalization and death," she said. "That is miraculous for a new vaccine for a new virus."
This report by
© 2022 The Canadian Press. All rights reserved., source