J&J vaccine a key player in achieving herd immunity by fall Along with being a single-shot vaccine, the Johnson & Johnson vaccine is easier to store and transport, as it doesn’t require the special refrigeration that the Pfizer and Moderna vaccines require. “It could be a game changer in the U.S. It’s such a flexible vaccine,” Will Humble, the executive director of the Arizona Public Health Association and former director of the Arizona Department of Health Services, told Arizona TV station KOLD. Fauci also sees a one-shot vaccine as a potential “game changer,” telling the New York Press Club on January 29 that there are logistical challenges to getting people to return for their second shot. With more than one vaccine, Fauci said, officials can deploy vaccines in situations where they’ll have the most effectiveness.