infected with the omicron variant. the big question is is if you have had omicron, will you get reinfected with this ba2 subvariant? and the answer is it's possible. data study recently in -- in preprint, not yet peer-reviewed, has suggested that you can get reinfected from ba1 to ba2. those -- though those reinfections are rare. >> all right. professor anne rimoin, we will leave it at that. thank you so much for lending your expertise to our audience. take care. >> my pleasure. you are watching "cnn newsroom." up next, firefighters in the u.s. -- they want to help colleagues in ukraine who also fight the flames. after the break, the americans are collecting all sorts of equipment the ukrainians might also need. we will talk to guys at the firehouse that started it all.