Prepends the string Levine_ to fields which do not start with the prefix Levine_

replaceline.awk

#! /bin/awk -f

BEGIN {
OFS = FS
}

{
    # only one line starting with #CHROM needs to be modified in file
    # all others just print out unmoodified
    if ( $1 !~ /^#CHROM/ ) {
        print $0;
    } else {
        for (i=1; i < NF; i++) {
            # samples start at 10th field
            # if field does not start with Levine
            # does inplace replacement of the field, pretty handy
            if ((i > 9) && ($i !~ /^Levine/)) $i="Levine_"$i;
        }
        print $0;
    }
}

Can be combined with bgziptabix to repace lines in VCF file:

for x in ../*.vcf.gz; do echo $x; zcat $x | replaceline | bgziptabix `basename $x` ; sleep 10; done