RT Journal Article SR Electronic T1 Vaccine safety: looking forward and back JF BMJ Global Health JO BMJ Global Health FD BMJ Publishing Group Ltd SP e005743 DO 10.1136/bmjgh-2021-005743 VO 6 IS Suppl 2 A1 Alexander Muir Walker A1 Walter A Orenstein YR 2021 UL http://gh.bmj.com/content/6/Suppl_2/e005743.abstract AB