little international schoolchildren and teachers with masks on faces. the concept of back to school, respiratory diseases, allergi

allergies allergy back blackboard cartoon celebration character cheerful children class classmate classroom collection concept congratulations coronavirus covid19 disease diseases education educator epidemic faces flat greeting holiday illustration infection international isolation lesson lettering little mask masks medical mentor multicultural pandemic pedagogue prevention protection pupil quarantine respiratory school schoolboy schoolchildren schoolgirl set stand teach teacher teachers tutor typography vector virus