By Nikhila Natarajan

New York, Jul 31 (IANS): Leaked documents from Americas premier public health fighting force show it is getting ready to go from what US president Joe Biden described as the countrys "summer of freedom" to "war has changed" on the Covid-19 delta variant in a short span of barely a month.

After Covid-19 has killed 612,000 people in the US over 19 months, the Centers for Disease Control and Prevention (CDC) is now coming around to the view that the delta variant is as contagious as chickenpox, according to internal documents scooped by the Washington Post.

Below are 5 highlights from the 25 slide deck that go to the core of the US public health concerns right now:

The CDC is readying to "acknowledge the war has changed". Its notes indicate that public understanding of breakthrough infections is all over the map. The CDC is still figuring out how to explain to the American people that vaccination reduces risk of death or severe disease 10 fold.

Citing large outbreaks among vaccinated people in Cape Cod town of Provincetown, Massachusetts, the CDC said that new evidence shows that breakthrough infections among those who got their two shots may be as transmissible as those in unvaccinated people.

Since January, people who got infected after vaccination make up a larger portion of hospitalisations and deaths among Covid-19 patients. This uptick coincides with the spread of the delta variant.

Communication challenges are coming from three directions: Local health departments are questioning vaccine effectiveness, the public is "convinced vaccines no longer work", and that booster doses are needed.

The CDC acknowledges that it is struggling to communicate that breakthrough cases are "rare" or a "small percentage" of total cases.

From the Joe Biden White House downwards, the US Covid Response team has been struggling for days to communicate the threat from new variants and the shifting guidance on masks.

New guidelines are likely soon, the White House indicated.