• Non replicating viral vector -first boost
• Janssen AD26 vaccine - fisrt boost
• Vaxzevria -first boost

• versus all
• vs potential COVID-19 treatments
• vs control

• COVID 19 hospitalized
• COVID 19 all comers
• COVID-19 mild to moderate
• COVID-19 severe or critically
• COVID 19 outpatients
• COVID-19 (hospitalized or not)
• COVID-19 prophylaxis (children)
• COVID-19 prophylaxis (excluding children)
• infections other than COVID-19
• Long COVID-19
• preventing respiratory virus transmission
• secondary prevention

  All patients omicron variant BA.1 (B.1.1.529)

    Top evidence (RCT only, high risk of bias excluded) Best available evidence (possibly low or very low) All RCTs All studies (RCT+OBS)   published meta-analysis   sensitivity analysis   studies

Non replicating viral vector -first boost in COVID-19 prophylaxis (excluding children) - Summary of results

TE: relative treatment effect (measured by a risk ratio, an odds ratio or an hazard ratio depending on what is reported in the papers); k: number of studies; n: total number of patients; ROB: risk of bias (ROB 2.0); Pub. bias: publication bias; OBS: observational studies; RCT: randomized clinical trials
studied treatment is better when TE > 1; studied treatment is better when TE < 1;