<prompt> tafsiri zifuatazo kutoka kwa swahili hadi kiingereza.taasisi hiyo pia ilionesha ongezeko dogo mno katika visa vya lahaja ya beta, iliyotambuliwa kwanza afrika kusini, ambayo inasemekana inahusika na ukwepaji kinga mwilini.  <response>: the institute also pointed out an extremely small increase in cases of the beta variant, first identified in south africa, which it says is characterized by partial immune evasion. 