UNIX script abruptly ending due to ssh command

Below UNIX script abruptly ends while reading second line from file. When I comment 'ssh' command the script works as expected. I think I will have to run ssh command in a different process, but haven't got a handle yet as regards to how to do that. Any help in resolving this problem is highly appreciated.

#!/usr/bin/ksh
exec 3<&0
exec 0<./bulkInput.dat
#cat ./bulkInput.dat | while read searchToken || (echo "reading failedi $?" &&  false)
index=0
while true
do
    index=`expr $index + 1`
    if [ $index -gt 450 ]
    then
            echo "Index limit reached. Now exiting"
            exit 0
    fi
    read searchToken
    if [ $? -ne "0" ]
    then
            echo "Read failed"
    fi
    echo "Search token is "${searchToken}
    echo "************************************ **********************************"
    echo "plsa0666 WSIP server " > WSIP.log
    ssh zq742888@plsa0666 'grep -r '$searchToken' /logs/jas/was60/wsip/wsip*/wsip*'    >>      WSIP.log
    echo "plsa0667 WSIP server " >> WSIP.log
    #ssh zq742888@plsa0667 'grep -r '$searchToken' /logs/jas/was60/wsip/wsip*/wsip*' >> WSIP.log
    echo "plsa0668 WSIP server " >> WSIP.log
    #ssh zq742888@plsa0668 'grep -r '$searchToken' /logs/jas/was60/wsip/wsip*/wsip*' >> WSIP.log
    echo "plsa4407 WSIP server " >> WSIP.log
    #ssh zq742888@plsa4407 'grep -r '$searchToken' /logs/jas/was60/wsip/wsip*/wsip*' >> WSIP.log
    echo "plsa0412 server " >> WSIP.log
    cp WSIP.log bulk/WSIP.log_${searchToken}
    echo $?
 done
 exec 0<&3
 echo "Exiting script"

you need to use " (double quotes)

try this....

ssh zq742888@plsa0666 "grep -r $searchToken /logs/jas/was60/wsip/wsip*/wsip*" >> WSIP.log