The Biden administration will direct $1.7 billion to sequence the emerging variants of the virus that causes COVID-19, the White House announced Friday.

New variants of the coronavirus make up about half of the current COVID-19 cases in the United States, according to the Centers for Disease Control and Prevention.

“The emergence of variants underscores the critical need for rapid and ongoing genomic surveillance,” CDC Director Rochelle Walensky told reporters in a press briefing.

The spending includes $1 billion to allow the CDC and states to expand efforts to sequence genomes and identify virus mutations. An initial $240 million will be distributed across states early next month.

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It includes another $400 million to launch six Centers of Excellence in Genomic Epidemiology, which will feature partnerships between state health departments and academic institutions, and $300 billion for a national bioinformatics infrastructure to improve data reporting.

The U.S. is sequencing about 29,000 samples per week, up from about 8,000 COVID-19 strains per week in early February. The administration previously announced $200 million to increase genomic sequencing.

The new spending comes as the number of reported cases is rising. The seven-day average number of cases is nearing 70,000 reported cases per day, up from about 53,000 cases per day four weeks ago, Walensky said.

Health officials also defended the pause in distribution of Johnson & Johnson’s COVID-19 vaccine that was announced earlier this week. The Advisory Committee on Immunization Practices is set to meet again next Friday to discuss the vaccine and the potential risk of dangerous blood clots that were reported in rare cases.

“What I would say to the American people is that what we found is really extremely rare cases through our vaccine safety monitoring system,” Walensky said, adding that people should still get vaccinated with either authorized vaccine from Pfizer or Moderna.

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