responsibly vaccinated, number one. number two, everyone eligible for the booster shot should get the booster shot. immediately -- [inaudible] that is the minimum that everyone should be doing. you know, we're always talking about -- [inaudible] i think it's a patriotic responsibility. >> reporter: after u.s. health officials spoke to south african scientists about how fast the new variant spreads and whether vaccines are effect i against it, the president made the decision to shut down travel from south africa and certain other countries, we are told the, out of an abundance of caution. the restrictions were announced quickly, but they don't take effect until monday, and some medical experts say that could considerably lessen their benefit. a white house official said today the prime minister has been brief on the latest concern the president has been briefed on the latest. any next steps will be guided by the science, and a big upcoming focus will be on testing for in this variant. fast-moving developments are taking the spotlight off of