What happened

Biotechnology company Novavax, Inc. (NVAX 2.95%) surged higher on Tuesday on what was an all-around bad day for the markets. The share price was up 5.8% from the previous day's close at around 12:35 p.m. ET and was up about 1.9% to $56.55 at the closing bell.

Meanwhile, all of the major indexes were down on Tuesday, with the Nasdaq falling 220 points, or 1.9%, the S&P 500 dropping 46 points, or 1.2%, and the Dow Jones down 229 points -- mostly on weak earnings reports from some major retailers.

So what

Two weeks ago, Novavax's COVID-19 vaccination, Nuvaxovid, got approved by the U.S. Food and Drug Administration (FDA) for emergency use authorization. Then last week the two-dose vaccine was unanimously recommended by the U.S. Centers for Disease Control's Advisory Committee for adults 18 years old and over.

On Tuesday, Novavax got more good news, as Nuvaxovid received expanded approval from the Japan Ministry of Health, Labour and Welfare (MHLW) for children between the ages of 12 and 17 in Japan. In April, the COVID-19 vaccine had been approved for adults 18 and over.

Also on Tuesday, the Australian Therapeutic Goods Agency (TGA) took similar action, approving Nuvaxovid for children between the ages of 12 and 17. It had approved the vaccine for adults back in January.

Now what

The Novavax COVID-19 vaccine is just the fourth to be approved in the United States. In phase 3 trials, the vaccine was effective 90% of the time. In addition to the U.S., about 40 other countries have approved the vaccine for adults.

The company has also developed a booster shot, targeted at coronavirus variants, but it has not yet been approved in the U.S. Look for that booster to get approval before the winter season.

As for the company's financials and outlook, look for the second-quarter earnings report when Novavax releases it next week on Aug. 4