Pfizer’s preliminary data highlights boosters’ effectiveness against Omicron COVID-19 variant

Pfizer today released preliminary laboratory findings on its COVID-19 vaccine’s effectiveness against the SARS-CoV-2 Omicron variant, offering an early look at the two, distinct dosing regiments currently authorized in the U.S. Pfizer said its standard, two-dose regimen resulted in a significant drop in the neutralization titers that protect against the virus. However, a third, booster dose was significantly more effective in combating the Omicron variant, providing a 25-fold increase in neutralization, compared to the two-dose regiment. Pfizer said it continues to collect additional lab data while also evaluating real-world effectiveness; an Omicron-specific vaccine is also in development.