Amid the fast spread of the Delta variant, the COVID-19 booster shots have been authorized by the United States officials, which was backed by information from the US and international studies.

The booster jabs were approved among some individuals who have received the vaccine but have weakened immune systems.

In a statement on Thursday, Food and Drug Administration (FDA) acting commissioner Dr. Janet Woodcock said that the agency “is especially cognizant that immunocompromised people are particularly at risk for severe disease.”

“After a thorough review of the available data, the FDA determined that this small, vulnerable group may benefit from a third dose of the Pfizer-BioNTech or Moderna vaccines,” she said.

US Centers for Disease Control and Prevention (CDC) director Dr. Rochelle Walensky early on Thursday said “emerging data show that certain people who are immunocompromised, such as people who have had an organ transplant and some cancer patients may not have had an adequate immune response to just two doses of the COVID vaccine.”

Authorizing the booster jabs came in a time when the Delta variant broke out internationally. The said variant is more infectious as compared to the original COVID-19 virus.

Florida, Texas and Arkansas are now facing an alarming rate of the said variant. The states of Missouri, Tennessee, and Illinois, meanwhile, have also experienced new outbreaks. In Arizona, Louisiana, and Mississippi, federal emergency response teams have already come to respond.

Based on the CDC data, more than 90 percent of the counties in the US are seeing “substantial or high transmission,” Al Jazeera reported.

On August 11, 132, 384 new cases of COVID-19 were reported by the CDS. The seven-day average has also increased by 24 percent, reaching 113, 000 cases daily as of August 11.