If the HTTP requests are being sent from a browser then you can take advantage of the Web Developer mode available in most modern browsers - by going to the 'Network' section and right clicking on a particular GET/POST requests and then one can optionally modify and resend selected requests and/or using curl (e.g. see FireFox, Chrome).
It's not straightforward to just resend a HTTP interactions that have been captured by Wireshark as the the HTTP is transported over TCP which needs to set up a new connection for each interaction so things like the TCP sequence numbers would need to be different. One approach would be to extract the HTTP content from the packet trace and resend that over a new TCP connection - Wireshark does allow for HTTP traces to be extracted which could be resent. However the latest version of tcpreplay suite from AppNeta now provides a tool tcpliveplay that says it can replay TCP streams so that seems like it could be the best option.
Otherwise for more programmatic control of packet replay one could use scapy as suggested in this answer, though one would need to extract the HTTP content and resend it on new connection(s).
