The Centers for Disease Control and Prevention (CDC) is working with U.S. drug regulators to assess whether a second COVID-19 vaccine booster is needed, CDC Director Rochelle Walensky said on March 17. “We at CDC have been following the vaccine effectiveness studies very, very carefully,” Walensky said. “What we’re seeing now is that we still have quite a bit of protection against severe disease, about 78 percent protection against severe disease, among those who were boosted first.” The doctor appeared to be referring to two studies the CDC published in its quasi-journal in February that found the effectiveness of a booster dose in those who received the Pfizer or Moderna primary series waned from 91 percent to 78 percent as time went on. The two-dose primary regimens of the shots provide little protection against infection from the Omicron virus variant and wane considerably in terms of shielding against severe disease, …