Pfizer Inc.’s omicron-targeting vaccine and a hybrid shot that fights the original strain as well as omicron prompted strong immune responses in a study that may pave the way for next-generation COVID-19 vaccines.

Pfizer and its vaccine partner, Germany’s BioNTech SE, said on Saturday that both of the new vaccine candidates had safety and tolerability profiles similar to the original shot.

The companies said the data will be discussed with regulators with the aim of quickly introducing a more tailored booster shot to address current and future variants.

Data from the late stage trial demonstrated that a booster dose of both omicron-modified vaccine candidates elicited a “substantially higher” immune response against omicron subvariant BA.1 as compared with the current COVID-19 vaccine.