SPRINGFIELD - The Illinois Department of Public Health (IDPH) is adopting the Centers for Disease Control and Prevention (CDC) recommendation to shorten the interval from 6 months to 5 months for when people who have received the Pfizer-BioNTech COVID-19 vaccine can get a booster dose. Only people who received two doses of Pfizer-BioNTech vaccine during their primary series can now receive an mRNA (Pfizer-BioNTech or Moderna) booster dose 5 months after their second shot.