• Carnival said its booking volumes on future cruises were up by 45% on a quarter-over-quarter basis.
• Carnival also said its cumulative advanced bookings for 2022 are ahead of its 2019 bookings.
• However, Carnival reported an adjusted net loss of $2 billion.

Carnival said Thursday that bookings were up 45% in the second quarter compared with the first quarter as the cruise industry continues its recovery from the Covid-19 pandemic.

The company also said its cumulative advanced bookings for 2022 are ahead of those from 2019.

However, Carnival reported an adjusted net loss of $2 billion for the second quarter of 2021. It expects a net loss on an adjusted basis for the third quarter and full year as well.

The company's monthly cash burn rate for the first half of 2021 was $500 million.

The company was able to raise $26.3 billion and was able to reduce future loan interest by $120 million per year through refinancing, Carnival Corporation President and CEO Arnold Donald said in an interview on CNBC's "Closing Bell" on Thursday.

"We have liquidity well into next year and, more importantly, well into the ability to get our full fleet up and going and then we'll have cash generation," Donald said. "Cash maximization will be the key to paying down the debt over time and getting up back to the credit rating that put us in the strong position to be able to survive this."

Due to several outbreaks aboard cruise ships last year, the cruise industry was one of the last sectors allowed to resume operations.

The Centers for Disease Control and Prevention allowed cruises to return this year with strict safety protocols and requirements in place to prevent outbreaks from occurring onboard.

"There are ways to manage this and we would just like to be treated similar to other sectors of travel and tourism," Donald said.

Carnival has resumed sailing or announced plans to resume sailing 42 ships from eight of the company's nine cruise brands by the end of November this year.

"We are working aggressively on our path to return our full fleet to operations by next spring. So far, we have announced that 42 ships, representing over half of our capacity, have been scheduled to return to serving guests by this fiscal year end," Donald said in a press release.

The company will be mandating that 95% of crew and guests be fully vaccinated, with protocols in place for unvaccinated guests including testing and mask wearing. The company thinks this would prevent the spread of the virus aboard cruises, Donald said on CNBC.

"The probability of an outbreak is very, very low, almost non-existent," Donald said. "You may have some individual cases, and we probably will have some."

However, despite routine testing at every port, Royal Caribbean cruises had two guests test positive aboard one of its first ships to set sail, the Celebrity Millennium.

Cruise line stocks are slowly rebounding this year after suffering huge losses during the pandemic.

Shares of Carnival fell 2.45% on Thursday. Its stock has risen 27% year to date.