Pfizer said Wednesday a booster dose of its COVID-19 vaccine could offer vital protection against the new Omicron variant.

The pharmaceutical company underscored that the initial two doses appear to be drastically less effective. Pfizer-BioNTech said two doses might not offer protection sufficient enough to prevent infection. However, according to the partners, lab tests showed a booster shot increased by 25 times the level of anti-virus antibodies in the host against the Omicron variant.

Blood samples taken a month after people received a booster shot showed they harboured levels of Omicron-fighting antibodies similar to those proven protective against predecessor COVID-19 variants after the two initial doses.

Pfizer announced its findings in a press release, and in the meantime, they are preliminary and haven't undergone any scientific review yet.

They currently are the first from a vaccine maker probing the efficacy of booster doses, which have been subject to debate for experts and bodies around the world, with some opposing the shots and others supporting them.

Experts have speculated that the surge in antibodies driven by the third COVID-19 vaccine dose could be enough to counter any efficacy decreases.

“Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it’s clear from these preliminary data that protection is maximized with a third dose of our vaccine,” Pfizer CEO Albert Bourla said in a statement.

While endorsing a Pfizer booster shot, Pfizer and BioNTech are working to create a vaccine specific to the Omicron variant in the case it is needed.