evidence: Pfizer-BioNTech COVID-19 Vaccine Demonstrates Strong Immune Response, High Efficacy and Favorable Safety in Children 6 Months to Under 5 Years of Age Following Third Dose - Based on topline data, three doses of the Pfizer-BioNTech COVID-19 Vaccine met all immunobridging criteria required for Emergency Use Authorization - The third 3-µg dose was well tolerated among 1,678 children under 5 years of age with a safety profile similar to placebo - Vaccine efficacy of 80.3% was observed in descriptive analysis of three doses during a time when Omicron was the predominant variant - The 3-µg dose level, which is one-tenth the dose for adults, was selected for children under 5 years of age based on safety, tolerability and immunogenicity [...] - chest pain - shortness of breath - feelings of having a fast-beating, fluttering, or pounding heart - Fainting can happen after getting injectable vaccines, including Pfizer-BioNTech COVID-19 Vaccine or COMIRNATY® (COVID-19 Vaccine, mRNA). Sometimes people who faint can fall and hurt themselves. For this reason, your vaccination provider may ask you to sit or lie down for 15 minutes after receiving the vaccine - Some people with weakened immune systems may have reduced immune responses to Pfizer-BioNTech COVID-19 Vaccine or COMIRNATY® (COVID-19 Vaccine, mRNA)