JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset>
 <p>Which of the following services would you like to start providing? (check all that apply)<span class="required">* </span><label for="med_field_005[]" class="error">This is a required field.</label></p>
 <label for="med_field_005_messboards" class="clearfix">
 <input type="checkbox" name="med_field_005[]" id="med_field_005_messboards" value="Message boards " class="required" tabindex="17">Message boards
 </label>
 <label for="med_field_005_linkedin" class="clearfix"> 
 <input type="checkbox" name="med_field_005[]" id="med_field_005_linkedin" value="LinkedIn group " tabindex="18">LinkedIn group
 </label>
 <label for="med_field_005_newsletter" class="clearfix"> 
 <input type="checkbox" name="med_field_005[]" id="med_field_005_newsletter" value="Newsletter " tabindex="19">Newsletter
 </label>
 <label for="med_field_005_other" class="clearfix"> 
 <input type="checkbox" name="med_field_005[]" id="med_field_005_other" value="Other" tabindex="20">Other 
 </label>
 </fieldset>
 
 <div id="provideServices">
 <fieldset>
 <p><label for="short_field_008">If Other please specify)</label>
 <input type="text" name="short_field_008" id="short_field_008" tabindex="21" /></p> 
 </fieldset>
 </div>

JavaScript

$(function() {
     $("#med_field_005_other").click(function(){
         if ($("#med_field_005_other").is(":checked"))
         {
             $('#short_field_008').addClass('required');
             $("#provideServices").show();
             alert($('#short_field_008').attr('class'));
         }
         else
         {
             $('#short_field_008').removeClass('required');
             $("#provideServices").hide();
             alert($('#short_field_008').attr('class'));
         }
     });  
     $("#provideServices").hide();
         
     var selector = "#med_field_005_messboards, #med_field_005_linkedin, #med_field_005_newsletter";
     
     $(selector).click(function(){            
         $('#short_field_008').removeClass('required');
     }); 
   
 });