 Don't get Prevnar 20 if you've had a severe allergic reaction to the vaccine or its ingredients. Adults with weakened immune systems may have a lower response to the vaccine. Side effects include pain and swelling at the injection site, fatigue, headache, muscle, and joint pain. For full prescribing information, please call 1-855-213-2138 or visit Prevnar20.com. Watch out! You got me! The galaxy is safe once again!