Moderna sold $5.9 billion of its Covid vaccine in the first quarter, blowing out revenue and profit expectations.

The biotech company’s shares soared by more than 7% in premarket trading Wednesday before falling. Its stock was down modestly in afternoon trading.

Moderna maintained its full-year guidance of $21 billion in Covid vaccine sales. That guidance is based on signed agreements with governments and does not include any orders from the U.S., so the final number could come in higher.

However, CFO David Meline said there is uncertainty in the 2022 sales guidance. COVAX, an international alliance that helps procure shots for some countries, chose against exercising an option for additional doses this year. The sales guidance still includes some contracted volume from COVAX but the group needs to confirm demand, Meline said.

Moderna’s first-quarter vaccine sales more than tripled over the same period last year, when it reported $1.7 billion in sales shortly after the shots first rolled out. The Covid vaccine for adults ages 18 and over, Spikevax, is the company’s only commercially available product.

CEO Stephane Bancel said Moderna expects stronger vaccine sales in the second half of the year as governments order more shots to get ready for fall inoculation campaigns. Bancel said Moderna also expects to receive regulatory approval in late summer for a redesigned vaccine that targets the mutations on the omicron variant in addition to the original strain that emerged in Wuhan, China, in 2019.

“The virus is mutating to become more and more infectious, and there’s waning immunity,” Bancel told CNBC’s Meg Tirrell in an interview Wednesday on “Squawk Box.” “It is going to be really important to boost people in the fall with a better adapted vaccine which is what we’re working towards.”

Moderna reported $3.66 billion in net income for the quarter, a threefold increase over the $1.2 billion it reported in the same period last year.

Here’s how the company performed compared with what Wall Street expected, based on analysts’ average estimates compiled by Refinitiv:

• Adjusted EPS: $8.58 per share, vs. $5.21 expected
• Revenue: $6.07 billion, vs. $4.62 billion expected

Moderna’s cash pile grew to $19.3 billion as of late March, up from $17.6 billion in December. Bancel said Moderna’s first priority is to invest in its product pipeline, but the company is actively looking at M&A opportunities around the world.

“In terms of M&A, I can tell you our teams have never been as busy,” Bancel told analysts during Moderna’s earnings call. “They are looking at a lot of opportunities literally across the world. We will not be shy to invest to expand the platform either through technology or through products.”

Moderna plans to release data in June on its vaccine that also targets omicron, President Stephen Hoge told analysts during the Wednesday call.

The current vaccines, which just target the Wuhan strain, are becoming less effective at preventing mild illness as highly mutated variants like omicron evade the antibodies that block infections. Although the current shots are still providing strong protection against severe illness and death, Moderna believes a vaccine that includes omicron will provide the broadest immunity against Covid as the virus continues to evolve, Hoge said.

The Food and Drug Administration’s advisory committee will meet June 28 to discuss whether the U.S. needs to adopt a redesigned vaccine that targets mutations on the virus. Bancel told CNBC that the turnaround will be tight if the FDA decides Americans need a new vaccine for the fall. Moderna and the other vaccine makers would only have July to order inputs and produce tens of millions of doses.

“If you look at the timelines, I don’t think any manufacturer will be able to be ready in August to fill the channel with product,” Bancel said.

Last week, Moderna asked the FDA to authorize its two-dose vaccine for children 6 months to 5 years old, the only age group left in the U.S. that is not yet eligible for a shot. The biotech company is also asking the FDA to authorize its shots for kids ages 6 to 11 and teenagers ages 12 to 17. Moderna expects to finish submitting FDA applications for its pediatric vaccines in the next two weeks, according to a company press release.

The FDA advisory committee has set several dates in June to review submissions on Covid vaccines for children. Bancel told CNBC on Wednesday that Moderna is working toward a June launch for the shots.