The Food and Drug Administration on Wednesday authorized updated versions of COVID-19 vaccines from Pfizer and Moderna that are tailored to be more effective against the Omicron variant.

Why it matters: The updated shots, retooled to target the BA.5 strain that accounts for most cases in the U.S. today, are expected to become available after Labor Day.

Between the lines: The reformulated mRNA shots got regulators' blessing without first being tested in humans.

• They are also the first to move ahead without an FDA advisory committee weighing in, marking a shift that more closely mirrors the annual flu shot approval process.
• The Biden administration is prioritizing speed over having all the data on how the vaccines work in real life. Some experts warn that this could make some people leery about getting the reformulated shots.

What to watch: Less than half of fully vaccinated Americans have received a first booster dose, per the CDC. Of those with a booster dose, only a third have received a second, although many Americans aren't yet eligible.

• A key CDC advisory committee is scheduled Thursday and Friday to consider whether or not to recommend Americans get the shot.
• The federal government is expected to authorize them for everyone 12 and older, although only Pfizer's shot will be available for children under 18.