mRNA boosters can be 90% effective against Omicron


A recent study from the Centers for Disease Control and Prevention reveal that mRNA boosters–that is, Pfizer and Moderna–can be as much as 90% effective against the Omicron variant.

The study focuses on vaccine effectiveness (VE), which compares the effectiveness of a vaccines to the original strain (in this case, the ancestor COVID-19 strain) with effectiveness to a variant.

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The study also found that VE for Delta, after a patient is boosted, can be as high as 94%.

Boosters have become increasingly important since Omicron emerged. Pre-Omicron, Director for the Centers of Disease Control and Prevention Dr. Rochelle Walensky recommended only high risk individuals, such as the elderly, immunosuppressed, and/or those whose work frequently exposes them to COVID, get the vaccine.

After Omicron, Dr. Walensky recommended everyone who is FDA-approved to receive the booster get the booster.

“Keep in mind that vaccinations started over a year ago,” said Dr. Annette David, Lead Epidemiologist for the State Epidemiology Outcomes Work Group. “As with anything, immune protection diminishes with time.

“With the onslaught of this new variant, it’s important to have the highest levels of immune protection as possible, which is why boosters have a very important role to play.”

VE with 2 doses

Accordingly, data also revealed that it matters when a person receives the second dose of their mRNA vaccine series. According to the CDC, “VE was significantly higher among patients who received their second mRNA COVID-19 vaccine dose [less than] 180 days before medical encounters compared with those vaccinated [after] 180 days.”

In an earlier article, PNC explained how the Omicron variant has immune evasion against the vaccines. But according to Dr. David, and as confirmed by the study, vaccines remain effective against severe illness, hospitalization, and death.

According to the CDC, the recent study implies that “[all] unvaccinated persons should start vaccination as soon as possible.” In Guam, Dr. David points out, in the new year, about 2000 Guam residents have begun their vaccine series, which DPHSS experts postulate is because the rise in COVID cases has encouraged them to act.