Table 1. Vaccine-Related Priorities to Control Viral Variants.*.
Evaluate existing vaccines for efficacy against variants |
Randomize vaccine schedules (e.g., agents and timing) during deployment and study postexposure prophylaxis |
Perform observational studies to estimate variant-specific vaccine effectiveness |
Expand worldwide capacity for sequencing of virus isolates |
Obtain sequences of clinical isolates from postlicensure studies, clinical trials, and vaccinees with serious breakthrough infections |
If current vaccines are inadequate, assess the effectiveness of new vaccines or modified vaccines against variants |
Evaluate new vaccines, ideally in randomized, placebo-controlled trials with clinical end points |
Develop and evaluate modified vaccines to achieve adequate efficacy against variants of concern |
Reduce the risk that additional variants of concern will emerge |
Promote public health measures (e.g., masking, social distancing, and vaccination) to reduce viral transmission |
Avoid the use of treatments with uncertain benefit that could drive the evolution of variants |
Consider targeted vaccination strategies to reduce community transmission |
Coordinate the worldwide response |
Identify and characterize viral variants of concern |
Select antigens for modified or new vaccines |
Share research results, including methods to link genetic sequence data with the antigenic characteristics of circulating SARS-CoV-2 |
Decide whether the variant data warrant modification of existing vaccines |
Promote convergence of regulatory assessments |
Establish a global data repository |
An existing vaccine is one that has been shown to be effective in clinical trials, a modified vaccine one in which a new antigen is delivered through an existing vaccine, and a new vaccine a completely new vaccine. SARS-CoV-2 denotes severe acute respiratory syndrome coronavirus 2.