: COVID-19 vs. the flu. If you test negative on an antigen test, don’t assume it’s a common cold or influenza. Here’s why No Comments Uncategorized If you have a COVID-19 vaccine, your immune system should kick in faster to recognize and fight the virus. If you have a COVID-19 vaccine, your immune system should kick in faster to recognize and fight the virus. Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to print (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pinterest (Opens in new window)Click to share on WhatsApp (Opens in new window)