A 6-month-old infant is brought to the pediatric clinic for a routine check-up. Which of the following vaccines should the nursing officer expect to administer according to the CDC's recommended immunization schedule?
1
MMR (measles, mumps, and rubella)
2
DTaP (diphtheria, tetanus, acellular pertussis)
3
Varicella
4
HPV (human papillomavirus)