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Volume 28, Number 8—August 2022

Factors Associated with Delayed or Missed Second-Dose mRNA COVID-19 Vaccination among Persons >12 Years of Age, United States

Lu Meng, Neil Chandra Murthy, Bhavini Patel Murthy, Elizabeth Zell, Ryan Saelee, Megan Irving, Hannah E. Fast, Patricia Castro Roman, Adam Schiller, Lauren Shaw, Carla L. Black, Lynn Gibbs-Scharf, LaTreace Harris, and Terence ChorbaComments to Author 
Author affiliations: Centers for Disease Control and Prevention Atlanta, Georgia, USA (L. Meng, N.C. Murthy, B.P. Murthy, E. Zell, R. Saelee, M. Irving, H.E. Fast, P.Castro Roman, A. Schiller, L. Shaw, C.L. Black, L. Gibbs-Scharf, L. Harris, T. Chorba); General Dynamics Information Technology Inc., Falls Church, Virginia, USA (L. Meng, R. Saelee); Stat-Epi Associates, Inc., Ponte Vedra Beach, Florida, USA (E. Zell); Deloitte Consulting LLP, New York, New York, USA (M. Irving); Booz Allen Hamilton, Inc., McLean, Virginia, USA (A. Schiller)

Main Article

Table 1

Timing of second dose of a 2-dose primary mRNA COVID-19 vaccine series, by sociodemographic factors, United States, December 14, 2020–December 31, 2021*

Variable Second dose timing, no. (%)
Total, no. (%)
Timely† Delayed‡ Missed§
135,979,226 (87.25)
5,224,993 (3.35)
14,643,23 (9.40)
Vaccine type, dose 1
Moderna 53,478,853 (87.04) 2,384,368 (3.88) 5,577,569 (9.08) 61,440,790
82,500,373 (87.39)
2,840,625 (3.01)
9,065,663 (9.60)
Age group, y
12–17 9,762,549 (86.60) 280,348 (2.49) 1,230,395 (10.91) 11,273,292
18–39 39,414,160 (85.13) 1,621,400 (3.50) 5,264,452 (11.37) 46,300,012
40–64 52,589,787 (88.27) 1,934,658 (3.25) 5,053,236 (8.48) 59,577,681
34,212,730 (88.41)
1,388,587 (3.59)
3,095,149 (8.00)
M 62,548,887 (86.85) 2,393,426 (3.32) 7,076,540 (9.83) 72,018,853
73,430,339 (87.60)
2,831,567 (3.38)
7,566,692 (9.03)
Metro 120,443,535 (87.14) 4,633,895 (3.35) 13,145,421 (9.51) 138,222,851
15,535,691 (88.15)
591,098 (3.35)
1,497,811 (8.50)
Social Vulnerability Index (12)
High 41,938,563 (85.92) 1,873,526 (3.84) 5,003,810 (10.25) 48,815,899
Medium 54,681,094 (86.36) 2,090,878 (3.30) 6,544,599 (10.34) 63,316,571
39,359,569 (90.04)
1,260,589 (2.88)
3,094,823 (7.08)
Hispanic 14,678,149 (83.38) 622,364 (3.54) 2,302,543 (13.08) 17,603,056
Black 9,711,675 (86.24) 446,893 (3.97) 1,102,700 (9.79) 11,261,268
American Indian/Alaska Native 860,111 (75.91) 54,520 (4.81) 218,355 (19.27) 1,132,986
Asian/OPI 6,047,962 (88.09) 210,615 (3.07) 607,609 (8.85) 6,866,186
White 58,829,793 (90.17) 1,972,730 (3.02) 4,445,116 (6.81) 65,247,639
45,851,536 (85.33)
1,917,871 (3.57)
5,966,909 (11.10)
South 41,188,846 (86.15) 1,775,680 (3.71) 4,844,461 (10.13) 47,808,987
Midwest 28,738,970 (91.57) 811,360 (2.59) 1,832,846 (5.84) 31,383,176
Mountain 11,446,355 (86.39) 574,949 (4.34) 1,227,706 (9.27) 13,249,010
Pacific 27,077,135 (83.19) 1,254,754 (3.86) 4,216,649 (12.95) 32,548,538
Noncontiguous 517,084 (74.17) 28,439 (4.08) 151,668 (21.75) 697,191
Northeast 27,010,836 (89.56) 779,811 (2.59) 2,369,902 (7.86) 30,160,549

*Pfizer-BioNTech,; Moderna, OPI, other Pacific Islander. †Second dose administered <42 d after first dose. ‡Second dose administered >42 d after second dose. §Received the first dose but no matching second dose on record.

Main Article

  1. Oliver  SE, Gargano  JW, Marin  M, Wallace  M, Curran  KG, Chamberland  M, et al. The Advisory Committee on Immunization Practices’ Interim Recommendation for Use of Pfizer-BioNTech COVID-19 Vaccine - United States, December 2020. MMWR Morb Mortal Wkly Rep. 2020;69:19224. DOIPubMedGoogle Scholar
  2. Oliver  SE, Gargano  JW, Marin  M, Wallace  M, Curran  KG, Chamberland  M, et al. The Advisory Committee on Immunization Practices’ Interim Recommendation for Use of Moderna COVID-19 Vaccine - United States, December 2020. MMWR Morb Mortal Wkly Rep. 2021;69:16536.Error! Hyperlink reference not valid. DOIPubMedGoogle Scholar
  3. Dooling  K, Marin  M, Wallace  M, McClung  N, Chamberland  M, Lee  GM, et al. The Advisory Committee on Immunization Practices’ updated interim recommendation for allocation of COVID-19 vaccine–UnitedStates, December 2020. MMWR Morb Mortal Wkly Rep. 2021;69:165760. DOIPubMedGoogle Scholar
  4. Kriss  JL, Reynolds  LE, Wang  A, Stokley  S, Cole  MM, Harris  LQ, et al.; CDC COVID-19 Vaccine Task Force. COVID-19 vaccine second-dose completion and interval between first and second doses among vaccinated persons—United States, December 14, 2020–February 14, 2021. MMWR Morb Mortal Wkly Rep. 2021;70:38995. DOIPubMedGoogle Scholar
  5. Wallace  M, Woodworth  KR, Gargano  JW, Scobie  HM, Blain  AE, Moulia  D, et al. The Advisory Committee on Immunization Practices’ interim recommendation for use of Pfizer-BioNTech COVID-19 vaccine in adolescents aged 12–15 years–United States, May 2021. MMWR Morb Mortal Wkly Rep. 2021;70:74952. DOIPubMedGoogle Scholar
  6. Fast  HE, Zell  E, Murthy  BP, Murthy  N, Meng  L, Scharf  LG, et al. Booster and additional primary dose COVID-19 vaccinations among adults aged >65 years—United States, August 13, 2021–November 19, 2021. MMWR Morb Mortal Wkly Rep. 2021;70:17359. DOIPubMedGoogle Scholar
  7. Anders  C. 15 million people in the U.S. have missed their second dose of the coronavirus vaccine, CDC says [cited 2022 Jan 30].
  8. Bradley  T, Grundberg  E, Selvarangan  R, LeMaster  C, Fraley  E, Banerjee  D, et al. Antibody responses after a single dose of SARS-CoV-2 mRNA vaccine. N Engl J Med. 2021;384:195961. DOIPubMedGoogle Scholar
  9. Bar-On  YM, Goldberg  Y, Mandel  M, Bodenheimer  O, Freedman  L, Kalkstein  N, et al. Protection of BNT162b2 vaccine booster against Covid-19 in Israel. N Engl J Med. 2021;385:1393400. DOIGoogle Scholar
  10. Doria-Rose  N, Suthar  MS, Makowski  M, O’Connell  S, McDermott  AB, Flach  B, et al.; mRNA-1273 Study Group. mRNA-1273 Study Group. Antibody persistence through 6 months after the second dose of mRNA-1273 vaccine for Covid-19. N Engl J Med. 2021;384:225961. DOIPubMedGoogle Scholar
  11. Centers for Disease Control and Prevention. Vaccine Administration Management System (VAMS) program information [cited 2022 Jan 30].
  12. Agency for Toxic Substances and Disease Registry. CDC/ATSDR Social Vulnerability Index [cited 2022 Jan 30].
  13. Centers for Disease Control and Prevention. NCHS urban-rural classification scheme for counties [cited 2022 Jan 30].
  14. Barek  MA, Aziz  MA, Islam  MS. Impact of age, sex, comorbidities and clinical symptoms on the severity of COVID-19 cases: A meta-analysis with 55 studies and 10014 cases. Heliyon. 2020;6:e05684. DOIPubMedGoogle Scholar
  15. Centers for Disease Control and Prevention. COVID-19 risks and vaccine information for older adults [cited 2021 Aug 4].
  16. Kates  J, Michaud  J, Tolbert  J, Artiga  S, Orgera  K; Kaiser Family Foundation. KFF COVID-19 Vaccine Monitor: winter 2021 update on parents' views of vaccines for kids [cited 2022 Jan 30].
  17. Murthy  BP, Zell  E, Saelee  R, Murthy  N, Meng  L, Meador  S, et al. COVID-19 vaccination coverage among adolescents aged 12–17 years—United States, December 14, 2020–July 31, 2021. MMWR Morb Mortal Wkly Rep. 2021;70:120613. DOIPubMedGoogle Scholar
  18. Camera  L. Survey shows parents clamoring for in-person learning despite spike in COVID-19 cases [cited 2022 Mar 4].
  19. Goldstein  D. Los Angeles mandates vaccines for students 12 and older [cited 2022 Mar 4].
  20. Camera  L. School vaccine mandates: here they come [cited 2022 Mar 4].
  21. Meo  SA, Bukhari  IA, Akram  J, Meo  AS, Klonoff  DC. COVID-19 vaccines: comparison of biological, pharmacological characteristics and adverse effects of Pfizer/BioNTech and Moderna Vaccines. Eur Rev Med Pharmacol Sci. 2021;25:16639.PubMedGoogle Scholar
  22. Chapin-Bardales  J, Gee  J, Myers  T. Reactogenicity following receipt of mRNA-based COVID-19 vaccines. JAMA. 2021;325:22012. DOIPubMedGoogle Scholar
  23. Ismail  L. Doctors say some are opting out of second vaccine dose in fear of side effects [cited 2022 Mar 4].
  24. Momplaisir  FM, Kuter  BJ, Ghadimi  F, Browne  S, Nkwihoreze  H, Feemster  KA, et al. Racial/ethnic differences in COVID-19 vaccine hesitancy among health care workers in 2 large academic hospitals. JAMA Netw Open. 2021;4:e2121931. DOIPubMedGoogle Scholar
  25. Lu  PJ, O’Halloran  A, Williams  WW, Lindley  MC, Farrall  S, Bridges  CB. Racial and ethnic disparities in vaccination coverage among adult populations in the U.S. Am J Prev Med. 2015;49(Suppl 4):S41225. DOIPubMedGoogle Scholar
  26. Nguyen  KH, Anneser  E, Toppo  A, Allen  JD, Scott Parott  J, Corlin  L. Disparities in national and state estimates of COVID-19 vaccination receipt and intent to vaccinate by race/ethnicity, income, and age group among adults ≥ 18 years, United States. Vaccine. 2022;40:10713. DOIPubMedGoogle Scholar
  27. Shrider  EA, Kollar  M, Chen  F, Semega  J. Income and poverty in the United States: 2020 [cited 2022 Mar 4].
  28. Goldman  N, Pebley  AR, Lee  K, Andrasfay  T, Pratt  B. Racial and ethnic differentials in COVID-19-related job exposures by occupational standing in the US. PLoS One. 2021;16:e0256085. DOIPubMedGoogle Scholar
  29. Hamel  L, Lopes  L, Sparks  G, Kirzinger  A, Kearney  A, Strokes  M, et al.; Kaiser Family Foundation. KFF COVID-19 vaccine monitor: October 2021 [cited 2022 Jan 30].
  30. Rusoja  EA, Thomas  BA. The COVID-19 pandemic, Black mistrust, and a path forward. EClinicalMedicine. 2021;35:100868. DOIPubMedGoogle Scholar
  31. Saelee  R, Zell  E, Murthy  BP, Castro-Roman  P, Fast  H, Meng  L, et al. Disparities in COVID-19 vaccination coverage between urban and rural counties—United States, December 14, 2020–January 31, 2022. MMWR Morb Mortal Wkly Rep. 2022;71:33540. DOIPubMedGoogle Scholar
  32. Ryerson  AB, Rice  CE, Hung  MC, Patel  SA, Weeks  JD, Kriss  JL, et al. Disparities in COVID-19 vaccination status, intent, and perceived access for noninstitutionalized adults, by disability status—National Immunization Survey Adult COVID module, United States, May 30–June 26, 2021. MMWR Morb Mortal Wkly Rep. 2021;70:136571. DOIPubMedGoogle Scholar
  33. Haggerty  J, Levesque  JF, Harris  M, Scott  C, Dahrouge  S, Lewis  V, et al. Does healthcare inequity reflect variations in peoples’ abilities to access healthcare? Results from a multi-jurisdictional interventional study in two high-income countries. Int J Equity Health. 2020;19:167. DOIPubMedGoogle Scholar
  34. Press  VG, Huisingh-Scheetz  M, Arora  VM. Inequities in technology contribute to disparities in COVID-19 vaccine distribution. JAMA Health Forum. 2021;2:e210264. DOIGoogle Scholar
  35. Mollalo  A, Tatar  M. Spatial modeling of COVID-19 vaccine hesitancy in the United States. Int J Environ Res Public Health. 2021;18:9488. DOIPubMedGoogle Scholar
  36. Levenson  E. These are the states with the highest and lowest vaccination rates [cited 2021 May 10].
  37. Willis  DE, Andersen  JA, Bryant-Moore  K, Selig  JP, Long  CR, Felix  HC, et al. COVID-19 vaccine hesitancy: Race/ethnicity, trust, and fear. Clin Transl Sci. 2021;14:22007. DOIPubMedGoogle Scholar
  38. Kaiser Family Foundation. State COVID-19 data and policy actions [cited 2022 Jan 30].
  39. Levenson  E. New York City now enforcing Covid-19 vaccine requirement for most indoor activities [cited 2022 Mar 4].
  40. Amirthalingam  G, Bernal  JL, Andrews  NJ, Whitaker  H, Gower  C, Stowe  J, et al. Serological responses and vaccine effectiveness for extended COVID-19 vaccine schedules in England. Nat Commun. 2021;12:7217. DOIPubMedGoogle Scholar
  41. Wallace  M, Moulia  D, Blain  AE, Ricketts  EK, Minhaj  FS, Link-Gelles  R, et al.; Centers for Disease Control and Prevention. The Advisory Committee on Immunization Practices’ recommendation for use of Moderna COVID-19 vaccine in adults aged ≥18 years and considerations for extended intervals for administration of primary series doses of mRNA COVID-19 vaccines—United States, February 2022. MMWR Morb Mortal Wkly Rep. 2022;71:41621. DOIPubMedGoogle Scholar

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Page created: June 22, 2022
Page updated: July 20, 2022
Page reviewed: July 20, 2022
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