Omicron: How effective are vaccines

POLITICS

Early data reveals how effective vaccines are against the Omicron variant

Published Monday, December 20, 2021 12:34PM EST Last Updated Monday, December 20, 2021 2:47PM EST

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As concerns over the new Omicron variant of COVID-19 mount, Canadians across the country are signing up for booster doses to increase their protection against the virus.

Studies are still underway to better understand the Omicron variant, with preliminary data slowly rolling in from Africa, where the strain was first detected.

The Public Health Agency of Canada’s (PHAC) website says early data suggests the Omicron variant may be more transmissible, “but evidence is limited at this time.”

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Omicron has been designated a “variant of concern” in Canada, with dozens of cases having now been detected across the country.

The variant has exhibited a high number of mutations to the virus’ spike protein, prompting fears that it may potentially be able to escape vaccine protection.

Each of the largest vaccine manufacturers have said they are studying how effective their shots are against the virus.

Here’s a look at what COVID-19 vaccine manufacturers have said so far about the Omicron variant.

MODERNA

On Monday, a third dose of its mRNA COVID-19 Spikevax vaccine appears to provide significant protection against the new Omicron variant.

The company said its shot can “boost neutralizing antibody levels 37-fold higher than pre-boost levels.”

What’s more, Moderna said a double dose of the booster shot was found to be significantly more effective.

The company said a 100-microgram booster dose – instead of 50 micrograms – increased the level of neutralizing antibodies 83-fold compared to pre-boost levels.

In a press release Monday, Moderna CEO Stephane Bancel said the “dramatic increase in COVID-19 cases from the Omicron variant is “concerning to all,” but said news of the booster data is “reassuring.”

He said to respond to the “highly transmissible variant” the company will “continue to rapidly advance an Omicron-specific booster candidate into clinical testing in case it becomes necessary in the future.”

“We will also continue to generate and share data across booster strategies with public health authorities to help them make evidence-based decisions on the best vaccination strategies against SARS-CoV-2.”

PFIZER-BIONTECH

Earlier this month, Pfizer and BioNTech provided an update on its mRNA vaccine’s efficacy against the Omicron variant.

In a press release on Dec. 8, the companies said preliminary laboratory studies showed that three doses of the Pfizer-BioNTech Comirnaty COVID-19 vaccine “neutralize the Omicron variant,” while two doses show “significantly reduced neutralization titres.”

Neutralization antibody titres are the level of antibodies in an individual’s blood that can kill a virus,

The university said the level of antibodies can derive from vaccination, natural infection or a mix of both.

The Pfizer-BioNTech data suggests a third dose of the vaccine “increases the neutralizing antibody titres by 25-fold,” compared to only two doses against the Omicron variant. The companies said two doses may still “induce protection against severe disease.”

Pfizer and BioNTech said they continue to “advance the development of a variant-specific vaccine for Omicron,” which is expected to be available by March.

OXFORD-ASTRAZENECA

In an update in November, the University of Oxford, which developed the Vaxzevria COVID-19 vaccine alongside AstraZeneca, said there was no evidence that the shot would not prevent severe disease from the Omicron variant.

The university said it has the “necessary tools and processes in place” for “rapid development of an updated COVID-19 vaccine” if necessary.

In a statement last month, AstraZeneca said it would be examining the impact of the variant on the vaccine and its COVID-19 antibody cocktail.

“As with any new emerging variants, we are looking into B.1.1.529 to understand more about it and the impact on the vaccine,” AstraZeneca said in a .

CTVNews.ca reached out to AstraZeneca for an update, but did not immediately hear back.

JOHNSON & JOHNSON

In a issued on Nov. 29, Johnson & Johnson said it was “closely monitoring newly emerging COVID-19 variants” and has been “evaluating the effectiveness of its COVID-19 vaccine across variants” including Omicron.

“The company is testing blood serum from participants in completed and ongoing booster studies to look for neutralizing activity against the Omicron variant,” the release reads.

Johnson & Johnson said the company was also “pursuing” an Omicron-specific vaccine and will “progress it as needed.”

However, a conducted by Humabs Biomed SA, a unit of Vir Biotechnology (VIR.O), and the University of Washington, among others, published on Friday found that the Johnson & Johnson vaccine had no neutralizing activity against the Omicron variant.

The study has not yet been peer reviewed.

In an email to CTVNews.ca on Monday, a spokesperson for Johnson & Johnson said there were “no updates” to the company’s Nov. 29 statement.

IS OMICRON LESS SEVERE THAN OTHER VARIANTS?

Dr. Isaac Bogoch, is an infectious diseases faculty member at the University of Toronto told CTV’s News Channel, that some early data from South Africa and Denmark and a “few other places” have “small arrows pointing in the direction that maybe [Omicron] is less severe” than other variants.

“That would be amazing,” he said on Friday. “But like anything else, there’s no one perfect dataset.”

Bogoch said we will “probably have a better understanding” of the variant in a week or two, when hospitalization data emerges from the U.K. and Denmark.

He said there are “significant caveats” with the data that is currently available.

“It think it’s premature to conclude that it is indeed less severe,” he said. “It might be, we hope it is, but you can’t plan on hope, you’ve got to plan for the best here and really get those third doses in.”

Bogoch said the Omicron variant is “extremely transmissible,” and added that COVID-19 is a “very challenging virus to control.”

He said even if the variant does prove to be less severe, if a large number of people become infected, the small percentage of those who do become sick enough to end up in a hospital could still be a significant amount.

Bogoch said Canada is pretty fragile from a health care capacity standpoint.”

“It doesn’t take too much to really stretch that beyond capacity,” he continued. “And that’s a Canada-wide issue. That’s an issue from coast to coast.”

With files from Reuters

RELATED IMAGES

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Dr. Veronica Legnini takes information from a driver during a COVID-19 vaccine drive through clinic at St. Lawrence College in Kingston, Ont., Dec. 18, 2021. (THE CANADIAN PRESS/Lars Hagberg)