The daughter is now said to be conscious, so how is this possible?

conventional nerve agent antidotes may not work.

At the right doses, nerve agents can kill within five to 15 minutes, says chemical weapons expert Mark Bishop at the Middlebury Institute of International Studies at Monterey. But the Novichok agents are thought to be even more dangerous and deadly; Mirzayanov claimsthat Novichok-5, for example, can be five to eight times more potent than VX.So the fact that the Skripals are still alive means that “it must have been low dose, or impure, or not administered in a really efficient way,” Bishop tells The Verge. “Because it doesn’t take very much of a nerve agent to be fatal.”
Treating Novichok poisoning is also “practically impossible,”according to the Handbook of Toxicology of Chemical Warfare Agents. For other nerve agents, the treatment is usually diazepam or Valium to stave off seizures, and atropine, which helps dry up the secretions that could choke or drown a nerve gas victim, Chai tells The Verge. That buys a little time for another drug called pralidoxime, or 2-PAM, to prevent the nerve agent from permanently shutting off that key enzyme. But Novichok agents might have more ways of harming people, according to the Handbook: “Consequently, conventional nerve agent antidotes may not work.”
“IT DOESN’T TAKE VERY MUCH OF A NERVE AGENT TO BE FATAL.”
It’s surprising to see Novichok surface in 2018, not least because Russia was supposed to have destroyed its 39,967 metric tons of chemical weapons by September 2017, according to the international organization that oversees the chemical weapons ban. The British prime minister has demanded that Moscow release information about the Novichok program, so it’s possible that we could soon learn more about these nerve agents.
Bishop, however, says not to bet on it: “The Russians are really good at keeping secrets.”
https://www.theverge.com/2018/3/14/1...soning-england