Moderna said its Covid-19 vaccine booster shot produced a “robust” antibody response against the highly contagious Delta variant, according to details of a study released Thursday with the company’s second-quarter earnings report.

In a phase 2 study, Moderna is testing a 50 microgram dose from three vaccine booster candidates in previously vaccinated people. The booster produced a promising immune response against three variants, including Delta, with antibody levels close to those in previously unvaccinated people who received two 100-microgram doses, the company said.

The data has been submitted to a peer-reviewed journal for publication, it said.

A Parrish Medical Center medical worker holds a vial of the Moderna COVID-19 vaccine on a ride through the vaccination clinic for Port Canaveral workers, workers at local hotels and restaurants, and residents of the Port Canaveral community.

Paul Hennessy | LightRakete | Getty Images

The company’s financial results for the second quarter exceeded Wall Street’s expectations for earnings and sales. Here’s how Moderna performed compared to Wall Street’s expectations according to Refinitiv’s average estimates:

  • Earnings per share: $ 6.46 versus $ 5.96 expected
  • Revenue: $ 4.35 billion versus $ 4.2 billion expected

The new data on boosters comes from the spread of the Delta variant across several countries, including the United States. The Centers for Disease Control and Prevention said the variant was as contagious as chickenpox and could make the elderly sicker even if they were fully vaccinated.

On slides attached to Thursday’s earnings report, Moderna said the variant will lead to an increase in breakthrough infections occurring in people who have been vaccinated.

“While we’re seeing Phase 3 efficacy over 6 months, we expect the neutralizing titers to continue to decline and eventually affect the vaccine’s effectiveness,” the company said. “Given this crossbreed, we believe a dose 3 refresh will likely be needed before the winter season.”

People in the United States are already finding ways to get booster shots because of concerns about the Delta. Still, on Wednesday the World Health Organization urged wealthy nations to stop distributing Covid booster vaccines, highlighting the global injustice in vaccines.

Moderna also said Thursday that a final analysis of its Phase III study found the two-dose vaccine was 93% effective, with effectiveness “lasting” until six months after the second dose.

By comparison, Pfizer and BioNTech reported that their vaccine effectiveness decreased to about 84% six months after the second vaccination.

Moderna, which was founded in 2010, was the second company after Pfizer-BioNTech to receive US approval for its Covid vaccine. Moderna’s Covid vaccine had sales of $ 4.2 billion in the three months ended June 30, according to earnings report.

The company plans to manufacture 800 million to 1 billion Covid vaccine doses this year. It has signed vaccine deals worth $ 20 billion in sales this year and deals worth $ 12 billion in 2022.