Boxes containing the Janssen Johnson & Johnson COVID-19 vaccine, shown at a vaccination center in Los Angeles last week.

Los Angeles, CA – April 15: A detail of Janssen Johnson & Johnson COVID-19 vaccine that is not currently being given out because it has been put on hold. It was the first day that people ages 16 and up can receive a Moderna or Pfizer vaccine at Kedren Health on Thursday, April 15, 2021 in Los Angeles, CA. Award-winning television producer, Marti Noxon, whos a big fan of Kedren Vaccines, sent an In-N-Out truck to feed 200+ volunteers who help make this vaccine program such a huge success and she did so on the day that vaccines are being made available to all people 16+ in Los Angeles. (Allen J. Schaben / Los Angeles Times via Getty Images)