N. P. Klein All authors

Interim estimates of 2024-2025 seasonal influenza vaccine effectiveness - four vaccine effectiveness networks, United States, October 2024-February 2025.

MMWR: Morbidity and Mortality Weekly Report. 2025

Vaccination during pregnancy in the Vaccine Safety Datalink, 2002-2022.

Pediatric Infectious Disease Journal. 2025

18 Years - VISION and IVY Networks, September 2023-January 2024.

MMWR: Morbidity and Mortality Weekly Report. 2024

49 Total citations

49 Recent citations

COVID-19 vaccination coverage and factors associated with vaccine uptake among people with HIV.

JAMA network open. 2024

4.86 Relative Citation Ratio

Clinical epidemiology and risk factors for critical outcomes among vaccinated and unvaccinated adults hospitalized with COVID-19-VISION Network, 10 states, June 2021-March 2023.

Clinical Infectious Diseases. 2024

16 Total citations

16 Recent citations

14 Field Citation Ratio

Coronavirus disease 2019 (COVID-19) vaccination and stillbirth in the Vaccine Safety Datalink.

Obstetrics and Gynecology. 2024

3 Total citations

Effectiveness of the original monovalent and bivalent COVID-19 vaccines against COVID-19-associated emergency department and urgent care encounters in pregnant persons who were not immunocompromised: VISION Network, June 2022-August 2023.

Open forum infectious diseases. 2024

Influenza vaccination accuracy among adults: self-report compared with electronic health record data.

Vaccine. 2024

2 Total citations

2 Recent citations

Influenza vaccine effectiveness against hospitalizations and emergency department or urgent care encounters for children, adolescents, and adults during the 2023-2024 season, United States.

Clinical Infectious Diseases. 2024

Influenza vaccine effectiveness against influenza A-associated emergency department, urgent care, and hospitalization encounters among US adults, 2022-2023.

Journal of Infectious Diseases. 2024

11 Total citations

8.07 Field Citation Ratio

2.51 Relative Citation Ratio

Interim estimates of 2023-24 seasonal influenza vaccine effectiveness - United States.

MMWR: Morbidity and Mortality Weekly Report. 2024

40 Total citations

40 Recent citations

JYNNEOS vaccine safety surveillance in the vaccine safety datalink during the 2022 mpox outbreak in the United States.

Infection. 2024

Lack of evidence for vaccine-associated enhanced disease from COVID-19 vaccines among adults in the Vaccine Safety Datalink.

Pharmacoepidemiology and Drug Safety. 2024

Respiratory syncytial virus (RSV) vaccine effectiveness against RSV-associated hospitalisations and emergency department encounters among adults aged 60 years and older in the USA, October, 2023, to March, 2024: a test-negative design analysis.

Lancet (London, England). 2024

14 Total citations

Risk of COVID-19 hospitalization and protection associated with mRNA vaccination among US adults with psychiatric disorders.

Influenza and other respiratory viruses. 2024

Vaccine effectiveness against pediatric influenza-A-associated urgent care, emergency department, and hospital encounters during the 2022-2023 season: VISION Network.

Clinical Infectious Diseases. 2024

5.14 Field Citation Ratio

8.13 Field Citation Ratio

A safety study evaluating non-COVID-19 mortality risk following COVID-19 vaccination.

Vaccine. 2023

25 Total citations

24 Recent citations

2.4 Relative Citation Ratio

Active postlicensure safety surveillance for recombinant zoster vaccine using electronic health record data.

American Journal of Epidemiology. 2023

10 Total citations

10 Recent citations

5.39 Field Citation Ratio

2.74 Relative Citation Ratio

Association between aluminum exposure from vaccines before age 24 months and persistent asthma at age 24 to 59 months.

Academic Pediatrics. 2023

10 Total citations

6.49 Field Citation Ratio

1.05 Relative Citation Ratio

COVID-19 booster vaccination in early pregnancy and surveillance for spontaneous abortion.

JAMA network open. 2023

13 Total citations

13 Recent citations

15 Field Citation Ratio

2.14 Relative Citation Ratio

COVID-19 vaccine safety surveillance in early pregnancy in the United States: design factors affecting the association between vaccine and spontaneous abortion.

American Journal of Epidemiology. 2023

4 Total citations

4 Recent citations

2.12 Field Citation Ratio

0.78 Relative Citation Ratio

Effectiveness of BNT162b2 COVID-19 vaccination in children and adolescents.

Pediatrics. 2023

10 Total citations

10 Recent citations

9.36 Field Citation Ratio

0.7 Relative Citation Ratio

Effectiveness of COVID-19 vaccines at preventing emergency department or urgent care encounters and hospitalizations among immunocompromised adults: an observational study of real-world data across 10 US states from August-December 2021.

Vaccine. 2023

6.56 Field Citation Ratio

0.27 Relative Citation Ratio

Effectiveness of the original monovalent coronavirus disease 2019 vaccines in preventing emergency department or urgent care encounters and hospitalizations among adults with disabilities: VISION Network, June 2021-September 2022.

Open forum infectious diseases. 2023

2 Total citations

2 Recent citations

1.87 Field Citation Ratio

0.19 Relative Citation Ratio

Estimates of bivalent mRNA vaccine durability in preventing COVID-19-associated hospitalization and critical illness among adults with and without immunocompromising conditions - VISION Network, September 2022-April 2023.

American Journal of Transplantation. 2023

8 Total citations

5.28 Field Citation Ratio

0.29 Relative Citation Ratio

Estimation of COVID-19 mRNA vaccine effectiveness and COVID-19 illness and severity by vaccination status during Omicron BA.4 and BA.5 sublineage periods.

JAMA network open. 2023

66 Total citations

65 Recent citations

62 Field Citation Ratio

7.2 Relative Citation Ratio

Impact of accounting for correlation between COVID-19 and influenza vaccination in a COVID-19 vaccine effectiveness evaluation using a test-negative design.

Vaccine. 2023

5 Total citations

5 Recent citations

2.94 Field Citation Ratio

0.41 Relative Citation Ratio

Influenza vaccination among pregnant people before and during the coronavirus disease 2019 (COVID-19) pandemic.

Obstetrics and Gynecology. 2023

0.94 Field Citation Ratio

0.24 Relative Citation Ratio

Influenza vaccination among pregnant women: self-report compared with vaccination data from electronic health records, 2018-2020 influenza seasons.

Public Health Reports. 2023

3.77 Field Citation Ratio

1.42 Relative Citation Ratio

Protection of two and three mRNA vaccine doses against severe outcomes among adults hospitalized with COVID-19--VISION Network, August 2021 to March 2022.

Journal of Infectious Diseases. 2023

11 Total citations

6.08 Field Citation Ratio

1.39 Relative Citation Ratio

Safety of measles, mumps, and rubella vaccine in adolescents and adults in the Vaccine Safety Datalink.

Vaccine. 2023

6.56 Field Citation Ratio

0.74 Relative Citation Ratio

Safety of simultaneous vaccination with COVID-19 vaccines in the Vaccine Safety Datalink.

Vaccine. 2023

8 Total citations

7.49 Field Citation Ratio

1.67 Relative Citation Ratio

Simultaneous administration of mRNA COVID-19 bivalent booster and influenza vaccines.

Vaccine. 2023

6 Total citations

3.53 Field Citation Ratio

1.04 Relative Citation Ratio

Tdap vaccination during pregnancy and risk of chorioamnionitis and related infant outcomes.

Vaccine. 2023

6 Total citations

7.02 Field Citation Ratio

0.93 Relative Citation Ratio

Vaccine effectiveness against influenza-associated urgent care, emergency department, and hospital encounters during the 2021-2022 season, VISION Network.

Journal of Infectious Diseases. 2023

16 Total citations

16 Recent citations

11 Field Citation Ratio

1.93 Relative Citation Ratio

Association of the COVID-19 pandemic with routine childhood vaccination rates and proportion up to date with vaccinations across 8 US health systems in the Vaccine Safety Datalink.

JAMA pediatrics. 2022

111

111 Total citations

72 Recent citations

72 Field Citation Ratio

9.79 Relative Citation Ratio

Early estimates of bivalent mRNA vaccine effectiveness in preventing COVID-19-associated emergency department or urgent care encounters and hospitalizations among immunocompetent adults - VISION Network, nine states, September-November 2022.

MMWR: Morbidity and Mortality Weekly Report. 2022

91 Total citations

89 Recent citations

50 Field Citation Ratio

3.96 Relative Citation Ratio

Effectiveness of 2, 3, and 4 COVID-19 mRNA vaccine doses among immunocompetent adults during periods when SARS-CoV-2 Omicron BA.1 and BA.2/BA.2.12.1 sublineages predominated - VISION Network, 10 states, December 2021-June 2022.

MMWR: Morbidity and Mortality Weekly Report. 2022

113

113 Total citations

73 Recent citations

62 Field Citation Ratio

6.39 Relative Citation Ratio

Effectiveness of COVID-19 Pfizer-BioNTech BNT162b2 mRNA vaccination in preventing COVID-19-associated emergency department and urgent care encounters and hospitalizations among nonimmunocompromised children and adolescents aged 5-17 years - VISION Network, 10 states, April 2021-January 2022.

MMWR: Morbidity and Mortality Weekly Report. 2022

178

178 Total citations

99 Recent citations

98 Field Citation Ratio

10 Relative Citation Ratio

Effectiveness of COVID-19 mRNA vaccines against COVID-19-associated hospitalizations among immunocompromised adults during SARS-CoV-2 Omicron predominance - VISION Network, 10 states, December 2021-August 2022.

MMWR: Morbidity and Mortality Weekly Report. 2022

70 Total citations

67 Recent citations

38 Field Citation Ratio

3.81 Relative Citation Ratio

Effectiveness of a third dose of mRNA vaccines against COVID-19-associated emergency department and urgent care encounters and hospitalizations among adults during oeriods of Delta and Omicron variant predominance - VISION Network, 10 states, August 2021-January 2022.

MMWR: Morbidity and Mortality Weekly Report. 2022

412

412 Total citations

160 Recent citations

115 Field Citation Ratio

26 Relative Citation Ratio

Effectiveness of homologous and heterologous COVID-19 booster doses following 1 Ad.26.COV2.S (Janssen (Johnson & Johnson)) vaccine dose against COVID-19-associated emergency department and urgent care encounters and hospitalizations among adults - VISION Network, 10 states, December 2021-March 2022.

MMWR: Morbidity and Mortality Weekly Report. 2022

2.79 Relative Citation Ratio

30 Recent citations

14 Field Citation Ratio

Effectiveness of two-dose vaccination with mRNA COVID-19 vaccines against COVID-19-associated hospitalizations among immunocompromised adults-nine states, January-September 2021.

American Journal of Transplantation. 2022

11 Total citations

6.08 Field Citation Ratio

0.54 Relative Citation Ratio

Estimation of COVID-19 mRNA vaccine effectiveness against medically attended COVID-19 in pregnancy during periods of Delta and Omicron variant predominance in the United States.

JAMA network open. 2022

3.76 Relative Citation Ratio

49 Recent citations

28 Field Citation Ratio

Incidence of Guillain-Barré syndrome after COVID-19 vaccination in the Vaccine Safety Datalink.

JAMA network open. 2022

124

124 Total citations

90 Recent citations

66 Field Citation Ratio

10 Relative Citation Ratio

Risk of myocarditis and pericarditis following BNT162b2 and mRNA-1273 COVID-19 vaccination.

Vaccine. 2022

53 Total citations

40 Recent citations

29 Field Citation Ratio

2.52 Relative Citation Ratio

Safety of COVID-19 vaccination in United States children ages 5 to 11 years.

Pediatrics. 2022

47 Total citations

32 Recent citations

25 Field Citation Ratio

2.8 Relative Citation Ratio

Safety of live-attenuated vaccines in children exposed to biologic response modifiers in utero.

Pediatrics. 2022

3 Total citations

0.16 Relative Citation Ratio

Waning 2-dose and 3-dose effectiveness of mRNA vaccines against COVID-19-associated emergency department and urgent care encounters and hospitalizations among adults during periods of Delta and Omicron variant predominance - VISION Network, 10 states, August 2021-January 2022.

MMWR: Morbidity and Mortality Weekly Report. 2022

429

429 Total citations

204 Recent citations

236 Field Citation Ratio

27 Relative Citation Ratio

Waning of vaccine effectiveness against moderate and severe covid-19 among adults in the US from the VISION network: test negative, case-control study.

BMJ (Clinical research ed.). 2022

157

157 Total citations

154 Recent citations

84 Field Citation Ratio

10 Relative Citation Ratio

Association of inadvertent 9-valent human papillomavirus vaccine in pregnancy with spontaneous abortion and adverse birth outcomes.

JAMA network open. 2021

19 Total citations

9.32 Field Citation Ratio

0.9 Relative Citation Ratio

COVID-19 vaccination coverage among insured persons aged ≥16 years, by race/ethnicity and other selected characteristics - eight integrated health care organizations, United States, December 14, 2020-May 15, 2021.

MMWR: Morbidity and Mortality Weekly Report. 2021

40 Total citations

19 Recent citations

10 Field Citation Ratio

2.18 Relative Citation Ratio

Developing algorithms for identifying major structural birth defects using automated electronic health data.

Pharmacoepidemiology and Drug Safety. 2021

13 Total citations

4.49 Field Citation Ratio

1.71 Relative Citation Ratio

Effectiveness of 2-dose vaccination with mRNA COVID-19 vaccines against COVID-19-associated hospitalizations among immunocompromised adults - nine states, January-September 2021.

MMWR: Morbidity and Mortality Weekly Report. 2021

176

176 Total citations

80 Recent citations

68 Field Citation Ratio

7.58 Relative Citation Ratio

Effectiveness of Covid-19 vaccines in ambulatory and inpatient care settings.

New England Journal of Medicine. 2021

428

428 Total citations

185 Recent citations

160 Field Citation Ratio

19 Relative Citation Ratio

Incidence of pediatric inflammatory bowel disease within the Vaccine Safety Datalink network and evaluation of association with rotavirus vaccination.

Vaccine. 2021

0.61 Relative Citation Ratio

1.7 Field Citation Ratio

Interim estimates of COVID-19 vaccine effectiveness against COVID-19-associated emergency department or urgent care clinic encounters and hospitalizations among adults during SARS-CoV-2 B.1.617.2 (Delta) variant predominance - nine states, June-August 2021.

MMWR: Morbidity and Mortality Weekly Report. 2021

152

152 Total citations

44 Recent citations

59 Field Citation Ratio

4.86 Relative Citation Ratio

Laboratory-confirmed COVID-19 among adults hospitalized with COVID-19-like illness with infection-induced or mRNA vaccine-induced SARS-CoV-2 immunity - nine states, January-September 2021.

MMWR: Morbidity and Mortality Weekly Report. 2021

100

100 Total citations

34 Recent citations

39 Field Citation Ratio

3.11 Relative Citation Ratio

Surveillance for adverse events after COVID-19 mRNA vaccination.

JAMA. 2021

539

539 Total citations

244 Recent citations

193 Field Citation Ratio

33 Relative Citation Ratio

Temporal trends in undervaccination: a population-based cohort study.

American Journal of Preventive Medicine. 2021

14 Total citations

6.17 Field Citation Ratio

1.07 Relative Citation Ratio

The childhood vaccination schedule and the lack of association with type 1 diabetes.

Pediatrics. 2021

4 Total citations

0.97 Field Citation Ratio

0.35 Relative Citation Ratio

Vaccine Safety Datalink infrastructure enhancements for evaluating the safety of maternal vaccination.

Therapeutic advances in drug safety. 2021

33 Total citations

23 Recent citations

16 Field Citation Ratio

2.69 Relative Citation Ratio

Association between rotavirus vaccination and type 1 diabetes in children.

JAMA pediatrics. 2020

30 Total citations

1.39 Relative Citation Ratio

10 Field Citation Ratio

Evaluating the association of stillbirths after maternal vaccination in the Vaccine Safety Datalink.

Obstetrics and Gynecology. 2020

19 Total citations

6.97 Field Citation Ratio

0.71 Relative Citation Ratio

SARS-CoV-2 infection among hospitalized pregnant women: reasons for admission and pregnancy characteristics - eight U.S. health care centers, March 1-May 30, 2020.

MMWR: Morbidity and Mortality Weekly Report. 2020

145

145 Total citations

43 Recent citations

53 Field Citation Ratio

6.85 Relative Citation Ratio

Vaccine. 2019

2.13 Field Citation Ratio

0.28 Relative Citation Ratio

Uptake and safety of hepatitis A vaccination during pregnancy: a Vaccine Safety Datalink study.

Vaccine. 2019

29 Total citations

1.04 Relative Citation Ratio

10 Field Citation Ratio

Infant hospitalizations and mortality after maternal vaccination.

Pediatrics. 2018

43 Total citations

1.75 Relative Citation Ratio

12 Field Citation Ratio

Risk of spontaneous abortion after inadvertent human papillomavirus vaccination in pregnancy.

Obstetrics and Gynecology. 2018

26 Total citations

7.71 Field Citation Ratio

1.02 Relative Citation Ratio

Safety of repeated doses of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine in adults and adolescents.

Pharmacoepidemiology and Drug Safety. 2018

1.85 Field Citation Ratio

0.27 Relative Citation Ratio

The safety of live attenuated influenza vaccine in children and adolescents 2 through 17 years of age: a Vaccine Safety Datalink study.

Pharmacoepidemiology and Drug Safety. 2018

13 Total citations

3.21 Field Citation Ratio

0.39 Relative Citation Ratio

Uptake and safety of Hepatitis B vaccination during pregnancy: a Vaccine Safety Datalink study.

Vaccine. 2018

25 Total citations

7.71 Field Citation Ratio

0.9 Relative Citation Ratio

Congenital microcephaly: case definition & guidelines for data collection, analysis, and presentation of safety data after maternal immunisation.

Vaccine. 2017

1.83 Relative Citation Ratio

17 Recent citations

13 Field Citation Ratio

Febrile seizure risk after vaccination in children one to five months of age.

Pediatric Neurology. 2017

21 Total citations

5 Recent citations

4.96 Field Citation Ratio

0.44 Relative Citation Ratio

First trimester influenza vaccination and risks for major structural birth defects in offspring.

Journal of Pediatrics. 2017

2.03 Relative Citation Ratio

13 Field Citation Ratio

Identifying birth defects in automated data sources in the Vaccine Safety Datalink.

Pharmacoepidemiology and Drug Safety. 2017

18 Total citations

4.84 Field Citation Ratio

0.77 Relative Citation Ratio

Maternal Tdap vaccination and risk of infant morbidity.

Vaccine. 2017

50 Total citations

1.87 Relative Citation Ratio

14 Field Citation Ratio

Maternal and infant outcomes after human papillomavirus vaccination in the periconceptional period or during pregnancy.

Obstetrics and Gynecology. 2017

32 Total citations

8.59 Field Citation Ratio

1.2 Relative Citation Ratio

Rates and risk factors associated with hospitalization for pneumonia with ICU admission among adults.

BMC Pulmonary Medicine. 2017

57 Total citations

19 Recent citations

18 Field Citation Ratio

1.88 Relative Citation Ratio

Febrile seizure risk after vaccination in children 6 to 23 months.

Pediatrics. 2016

76 Total citations

2.21 Relative Citation Ratio

17 Field Citation Ratio

Influenza vaccination during pregnancy: influenza seasons 2002-2012, Vaccine Safety Datalink.

American Journal of Preventive Medicine. 2016

31 Total citations

5.28 Field Citation Ratio

1.58 Relative Citation Ratio

Maternal Tdap vaccination: coverage and acute safety outcomes in the vaccine safety datalink, 2007-2013.

Vaccine. 2016

102

102 Total citations

4.36 Relative Citation Ratio

25 Field Citation Ratio

Risk of anaphylaxis after vaccination in children and adults.

Journal of Allergy and Clinical Immunology. 2016

326

326 Total citations

74 Recent citations

69 Field Citation Ratio

8.02 Relative Citation Ratio

Risk of preterm or small-for-gestational-age birth after influenza vaccination during pregnancy: caveats when conducting retrospective observational studies.

American Journal of Epidemiology. 2016

60 Total citations

13 Recent citations

11 Field Citation Ratio

2.59 Relative Citation Ratio

Association of Tdap vaccination with acute events and adverse birth outcomes among pregnant women with prior tetanus-containing immunizations.

JAMA. 2015

100

100 Total citations

3.32 Relative Citation Ratio

28 Field Citation Ratio

Childhood vaccines and Kawasaki disease, Vaccine Safety Datalink, 1996-2006.

Vaccine. 2015

40 Total citations

6.97 Field Citation Ratio

1.62 Relative Citation Ratio

Safety of measles-containing vaccines in 1-year-old children.

Pediatrics. 2015

44 Total citations

8.49 Field Citation Ratio

1.43 Relative Citation Ratio

Safety of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis and influenza vaccinations in pregnancy.

Obstetrics and Gynecology. 2015

93 Total citations

10 Recent citations

19 Field Citation Ratio

3.44 Relative Citation Ratio

Evaluation of the association of maternal pertussis vaccination with obstetric events and birth outcomes.

JAMA. 2014

190

190 Total citations

24 Recent citations

54 Field Citation Ratio

6.36 Relative Citation Ratio

Receipt of pertussis vaccine during pregnancy across 7 Vaccine Safety Datalink Sites.

Preventive Medicine. 2014

57 Total citations

9.24 Field Citation Ratio

2.38 Relative Citation Ratio

Safety of diphtheria, tetanus, acellular pertussis and inactivated poliovirus (DTaP-IPV) vaccine.

Vaccine. 2014

37 Total citations

7.21 Field Citation Ratio

1.11 Relative Citation Ratio

Vaccinations given during pregnancy, 2002-2009: a descriptive study.

American Journal of Preventive Medicine. 2014

17 Total citations

0.69 Relative Citation Ratio

1.8 Field Citation Ratio

Effect of age on the risk of fever and seizures following immunization with measles-containing vaccines in children.

JAMA pediatrics. 2013

70 Total citations

6.41 Field Citation Ratio

2.34 Relative Citation Ratio

Measles-containing vaccines and febrile seizures in children age 4 to 6 years.

Pediatrics. 2012

48 Total citations

5 Recent citations

7.97 Field Citation Ratio

1.5 Relative Citation Ratio

Risk of rheumatoid arthritis following vaccination with tetanus, influenza and hepatitis B vaccines among persons 15-59 years of age.

Vaccine. 2011

44 Total citations

1.09 Relative Citation Ratio

7.9 Field Citation Ratio

Safety of trivalent inactivated influenza vaccine in children aged 24 to 59 months in the vaccine safety datalink.

Archives of Pediatrics and Adolescent Medicine. 2011

38 Total citations

6.82 Field Citation Ratio

1.08 Relative Citation Ratio

Lack of association between acellular pertussis vaccine and seizures in early childhood.

Pediatrics. 2010

55 Total citations

9.45 Field Citation Ratio

1.3 Relative Citation Ratio

Measles-mumps-rubella-varicella combination vaccine and the risk of febrile seizures.

Pediatrics. 2010

284

284 Total citations

6.68 Relative Citation Ratio

41 Field Citation Ratio

Varicella vaccination and ischemic stroke in children: is there an association?.

Pediatrics. 2009

39 Total citations