they re talking about socializing with someone at length, someone who you may have a prolonged period of sharing enclosed air with. and this is an example of cdc needing to communicate better. my view is that their isolation and quarantine guidance was generally right, but failing to explain it clearly, explain the choices that were made, why they were made, what the judgments were, what the science is that has led to a vacuum when people are making kind of pot shot criticisms at the cdc. well, that s in the united states. in israel, early data now suggests the fourth covid vaccine dose can boost antibodies to even higher levels, but it may not be enough to protect against possible breakthrough infections caused by the omicron variant. now, meantime, moderna says it should have data available on its omicron-specific vaccine soon and looks to share the information by march.