Members of the Tshwane Special Infectious Unit on COVID-19 pick up a patient Jan. 15 in Pretoria, South Africa. Pfizer’s vaccine was only slightly less effective against the South Africa variant compared with the others. The Johnson & Johnson results provided further evidence that the problem was serious. In the meantime, Moderna has announced efforts to develop a booster shot to add to its current two-shot regimen in order to fend off the South Africa variant. The United States reported its first known cases of the South Africa variant Thursday, in two people in South Carolina.
