Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults

Added November 12, 2019

Read the full review here

Studies support giving varicella vaccine to a child, particularly if given within three days of contact with a chickenpox case. Although mild chickenpox may still occur in some cases, the vaccine is likely to prevent moderate to severe cases of chickenpox 

Many countries do not routinely immunise children against varicella and exposures continue to occur. Although the disease is often mild, complications such as secondary bacterial infection, pneumonitis and encephalitis occur in about 1% of cases, usually leading to hospitalisation. This review found that three separate trials investigated the effectiveness of giving varicella vaccine as postexposure prophylaxis following household exposure of nonimmune children to siblings with varicella compared to a placebo. Overall, 13 of 56 (18%) vaccine recipients developed varicella compared with 42 of 54 (78%) placebo (or no vaccine) recipients. The number of participants in these three trials was small and the quality of the included studies variedThere have been no trials of this type undertaken in adults, and none of the trials commented on adverse events following immunisation, such as fever or injection site reactions.