The United States has authorised an extra dose of Covid vaccine for people with weakened immune systems, as the country struggles to thwart the Delta variant.
Emergency use authorisation for a third injection of Pfizer-BioNTech and Moderna vaccines was granted by the US Food and Drug Administration (FDA) regulator. "The country has entered yet another wave of the Covid-19 pandemic, and the FDA is especially cognisant that immune-compromised people are particularly at risk for severe disease," said acting FDA Commissioner Janet Woodcock in a statement.
The FDA said the additional dose was for organ transplant recipients or those with equivalent weakened immune systems. Some United States media reports suggest that one million Americans may