International experts say the COVID-19 delta variant is as contagious as chickenpox. 

The US Centers for Disease Control and Prevention (CDC) is considering changing its advice on how the US should fight the coronavirus, according to reports. 

CDC briefing notes to staff allegedly seen by the Washington Post say the COVID-19 delta variant could cause infections that are more contagious than the flu, smallpox and Ebola virus, and officials must “acknowledge the war has changed.”

The notes reportedly cite recently obtained, still-unpublished data from outbreak investigations and studies showing that vaccinated individuals infected with delta could transmit the virus as easily as those who are unvaccinated. 

The experts appear to be warning that vaccinated people infected with the delta strain have measurable viral loads similar to those who are unvaccinated and infected with the same variant.

On a global scale, the World Health Organization (WHO) says that its approved vaccines remain effective, but even so, the world risks losing its hard-won gains in fighting the virus as the Delta variant spreads.

COVID-19 infections are up by 80 per cent in the past four weeks, globally. The delta variant has been detected in 132 countries and is now the dominant global strain.