BOSTON (CBS) – Some more good news from Pfizer. The company says its COVID-19 vaccine remains highly effective for at least six months.

It’s been unclear how long COVID-19 vaccines might provide protection, but based on a late-stage trial, Pfizer says its vaccine is more than 91% effective against the symptomatic disease at least six months after the second dose. They say they hope to provide more information about whether that protection lasts even longer.

They also found that the vaccine had a good effect against the so-called South African variant and say they haven’t found serious safety concerns so far.

They plan to apply for full FDA approval in the coming weeks.

Dr. Mallika Marshall