State Immunization Information System Research Articles

Characteristics Associated With Measles, Mumps, and Rubella Coverage and Exemptions After a School Immunization Law Change in Washington, 2019-2020.

We aimed to better understand the impact of statewide legislation removing personal belief exemptions (PBEs) for the measles, mumps, and rubella (MMR) school immunization requirement and factors associated with resulting health-seeking behaviors. We used chi-squared tests and logistic regression models to determine individual- and school-level characteristics associated with holding a MMR PBE and with post-law MMR immunization status among students linked to the Washington State Immunization Information System. Of students with a MMR PBE pre-law change, 43.0% completed the MMR vaccine series and 40.4% sought another exemption type. Religious exemptions made up most new MMR exemptions signed (71.8%), followed by medical exemptions (18.5%), and religious membership exemptions (9.7%). Students were more likely to complete the vaccine series post-law change if they attended a school with a low school-level MMR exemption rate, a public school, or held a lower number of school-required immunization exemptions. This study confirms previous concerns that parents might replace their PBE with another exemption type; however, nearly half the students in the cohort completed the MMR vaccine series. Our findings suggest that targeted immunization policies can increase MMR coverage 1-year post-law change but must account for a replacement effect when exemption categories are eliminated.

Increased Identification of Vaccines for Vaccine Safety Surveillance Through Linkage With the Minnesota Immunization Information Connection as of December 31, 2023.

The HealthPartners' Vaccine Safety Datalink (VSD) team maintains standardized files of vaccines from medical and pharmacy claims and electronic health records (established data sources) for safety surveillance. Since 2021, for selected vaccines, data from the Minnesota Immunization Information Connection (MIIC), Minnesota's immunization information system, have been added to the HealthPartners' VSD files. We examined how MIIC data have enhanced the identification of novel and routine vaccines. We describe the approach to incorporating MIIC data. We determined and compared the number and proportion of vaccines identified from established data sources with the additional capture of vaccine data identified from MIIC, in which age group and period of observation varied by vaccine. As of December 31, 2023, of 1 099 411 people in the HealthPartners' VSD cohort, 1 001 400 people (91%) were linked with an MIIC record. Across all data sources, for the full cohort, >2.7 million COVID-19 vaccine doses were recorded since 2020, >4000 mpox vaccine doses since 2022, >7.3 million influenza vaccine doses since 2004, >600 000 human papillomavirus (HPV) vaccine doses since 2006, and >1.1 million diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine doses since 2004. For COVID-19 vaccines, about 30% of vaccine doses were exclusively captured from MIIC, with the remaining 70% from established data sources. For the mpox vaccine, about 42% were exclusively from MIIC. For influenza, HPV, and DTaP vaccines, about 20%, 14%, and 17%, respectively, were exclusively identified from MIIC. Incorporation of data from state immunization information systems into existing vaccine data files can enhance monitoring on the safety of novel vaccines administered outside traditional health care settings and can enhance data quality for routine childhood and adult vaccines.

Vaccine Coverage at 36 Months and 7 Years by Parental Birth Country, Washington State.

Ensuring equitable vaccination access for immigrant communities is critical for guiding efforts to redress health disparities, but vaccine coverage data are limited. We evaluated childhood vaccination coverage by parental birth country (PBC) through the linkage of Washington State Immunization Information System data and birth records. We conducted a retrospective cohort evaluation of children born in Washington from January 1, 2006 to November 12, 2019. We assessed up-to-date vaccination coverage status for measles, mumps, and rubella (MMR), diphtheria, tetanus, and pertussis (DTaP), and poliovirus vaccines at ages 36 months and 7 years. Children with ≥1 parent(s) born in selected non-US countries were compared with children with 2 US-born parents, using Poisson regression models to provide prevalence ratios. We identified 902 909 eligible children, of which 24% had ≥1 non-US-born parent(s). Vaccination coverage at 36 months by PBC ranged from 41.0% to 93.2% for ≥1 MMR doses and ≥3 poliovirus doses and 32.6% to 86.4% for ≥4 DTaP doses. Compared with children of US-born parents, the proportion of children up to date for all 3 vaccines was 3% to 16% higher among children of Filipino-, Indian-, and Mexican-born parents and 33% to 56% lower among children of Moldovan-, Russian-, and Ukrainian-born parents. Within-PBC coverage patterns were similar for all vaccines with some exceptions. Similar PBC-level differences were observed at 7 years of age. The linkage of public health data improved the characterization of community-level childhood immunization outcomes. The findings provide actionable information to understand community-level vaccination determinants and support interventions to enhance vaccine coverage.

Barriers to and Facilitators of Pediatric Vaccination Reporting in Four US States, 2023.

In a 2023 sequential explanatory mixed-methods study in four US states, we identified barriers and facilitators experienced by Vaccines for Children (VFC) program providers in reporting vaccination data to state immunization information systems (IISs). We found the following: VFC providers value accurate, robust, and widely used IISs. IIS reporting is easier with but does not require an electronic health record. Negative interactions with IISs and VFC officials and limited practice capacity are barriers to reporting. The COVID-19 pandemic highlighted the need for a nationwide vaccination database. (Am J Public Health. 2024;114(6):569-574. https://doi.org/10.2105/AJPH.2024.307638).

Tri-State Evaluation of the Effects of the COVID-19 Pandemic on Routine Vaccine Uptake in Iowa, Minnesota, and North Dakota, 2017-2021.

The objective of this analysis was to evaluate and compare the effects of the COVID-19 pandemic on routine and annual influenza vaccination in Iowa, Minnesota, and North Dakota. Routine and annual influenza vaccination uptake and coverage between 2017 and 2021 was collected from each state's immunization information system (IIS) by age group and stratified by provider and vaccine type. Data from 2017 to 2019 were averaged to obtain a pre-pandemic baseline and compared to 2020 and 2021 data. Percent changes were calculated to evaluate differences in uptake and coverage. Changes in coverage and administration varied by state, but each state had some level of decreased administration across the different age groups and vaccine types. The most consistent decreases in vaccine administration occurred in the 15-year-old cohort with each state finding decreased administrations in 2020 and 2021. The 12-year-old age group had decreased administration of hepatitis B, measles, mumps, and rubella, and varicella vaccine while the 2-year-old age group had the most consistent decrease in coverage across all vaccines analyzed. Trends by provider type were also noted in all three states, with local public health (LPH) experiencing the largest and most consistent declines in vaccine administrations by age group. Adult influenza coverage improved to varying degrees in 2020 (+ 14.1% IA, + 2.1% MN, + 1.5% ND), but either decreased or approached the 2017-19 average in 2021. All three states saw some level of decreased vaccine administration across the age groups, vaccines, and provider types assessed. The COVID-19 pandemic affected how many children and adults received recommended immunizations, leaving communities vulnerable to vaccine-preventable diseases.

Effectiveness of Bivalent mRNA COVID-19 Vaccines in Preventing SARS-CoV-2 Infection in Children and Adolescents Aged 5 to 17 Years.

Bivalent mRNA COVID-19 vaccines were recommended in the US for children and adolescents aged 12 years or older on September 1, 2022, and for children aged 5 to 11 years on October 12, 2022; however, data demonstrating the effectiveness of bivalent COVID-19 vaccines are limited. To assess the effectiveness of bivalent COVID-19 vaccines against SARS-CoV-2 infection and symptomatic COVID-19 among children and adolescents. Data for the period September 4, 2022, to January 31, 2023, were combined from 3 prospective US cohort studies (6 sites total) and used to estimate COVID-19 vaccine effectiveness among children and adolescents aged 5 to 17 years. A total of 2959 participants completed periodic surveys (demographics, household characteristics, chronic medical conditions, and COVID-19 symptoms) and submitted weekly self-collected nasal swabs (irrespective of symptoms); participants submitted additional nasal swabs at the onset of any symptoms. Vaccination status was captured from the periodic surveys and supplemented with data from state immunization information systems and electronic medical records. Respiratory swabs were tested for the presence of the SARS-CoV-2 virus using reverse transcriptase-polymerase chain reaction. SARS-CoV-2 infection was defined as a positive test regardless of symptoms. Symptomatic COVID-19 was defined as a positive test and 2 or more COVID-19 symptoms within 7 days of specimen collection. Cox proportional hazards models were used to estimate hazard ratios for SARS-CoV-2 infection and symptomatic COVID-19 among participants who received a bivalent COVID-19 vaccine dose vs participants who received no vaccine or monovalent vaccine doses only. Models were adjusted for age, sex, race, ethnicity, underlying health conditions, prior SARS-CoV-2 infection status, geographic site, proportion of circulating variants by site, and local virus prevalence. Of the 2959 participants (47.8% were female; median age, 10.6 years [IQR, 8.0-13.2 years]; 64.6% were non-Hispanic White) included in this analysis, 25.4% received a bivalent COVID-19 vaccine dose. During the study period, 426 participants (14.4%) had laboratory-confirmed SARS-CoV-2 infection. Among these 426 participants, 184 (43.2%) had symptomatic COVID-19, 383 (89.9%) were not vaccinated or had received only monovalent COVID-19 vaccine doses (1.38 SARS-CoV-2 infections per 1000 person-days), and 43 (10.1%) had received a bivalent COVID-19 vaccine dose (0.84 SARS-CoV-2 infections per 1000 person-days). Bivalent vaccine effectiveness against SARS-CoV-2 infection was 54.0% (95% CI, 36.6%-69.1%) and vaccine effectiveness against symptomatic COVID-19 was 49.4% (95% CI, 22.2%-70.7%). The median observation time after vaccination was 276 days (IQR, 142-350 days) for participants who received only monovalent COVID-19 vaccine doses vs 50 days (IQR, 27-74 days) for those who received a bivalent COVID-19 vaccine dose. The bivalent COVID-19 vaccines protected children and adolescents against SARS-CoV-2 infection and symptomatic COVID-19. These data demonstrate the benefit of COVID-19 vaccine in children and adolescents. All eligible children and adolescents should remain up to date with recommended COVID-19 vaccinations.

Effectiveness of XBB.1.5 Vaccines Against Omicron Subvariants

Background: The updated Moderna, Pfizer-BioNTech, and Novavax COVID-19 vaccines containing the SARS-CoV-2 omicron XBB.1.5 strain have replaced their predecessors in the United States and in other countries since the fall of 2023. The clinical impact of these vaccines on currently circulating variants was unknown. Aims: We aimed to assess the effectiveness of the updated XBB.1.5 vaccines against currently circulating omicron subvariants. Methods: We examined data on the administration of XBB.1.5 vaccines and the incidence of COVID-19 between September 11 and November 27, 2023 for approximately 2 million persons by linking records from the Nebraska Electronic Disease Surveillance System and the Nebraska State Immunization Information System. We used Cox regression to estimate the effects of XBB.1.5 vaccines on the risk of COVID-19, as a function of time elapsed since vaccination, while adjusting for demographic factors, previous infection history, and previous vaccination history. Results: The effectiveness (i.e., proportionate reduction of risk) for XBB.1.5 vaccines against SARS-CoV-2 infection was 63.0% (95% confidence interval [CI], 48.6 to 73.4) 4 weeks after vaccination and 67.1% (95% CI, 49.9 to 78.4) 6 weeks after vaccination; vaccine effectiveness started to decline after 6 weeks. Vaccine effectiveness was broadly similar across subgroups defined by age, sex, race and ethnicity, socioeconomic status, and previous immunity status. Conclusion: XBB.1.5 vaccines were effective against currently circulating variants, regardless of age, sex, race and ethnicity, socioeconomic status, or previous immunity status. These findings can be used to develop effective prevention strategies against COVID-19.

Utilization of street-based COVID-19 vaccination clinics in Phoenix's homeless population.

The novel Coronavirus (COVID-19) is a highly contagious viral illness that has caused the most significant global health crisis in recent human history. Individuals experiencing homelessness represent one of the more vulnerable populations for COVID-19 infection and morbidity. Amongst individuals experiencing homelessness in Phoenix, a student-led interprofessional organization called Street Medicine Phoenix (SMP) sought to both reduce the risk of COVID-19 transmission and morbidity/mortality related to infection. Through collaborations with the Maricopa County Department of Public Health and various community organizations, SMP developed a format for street-based vaccination clinics. SMP deployed these clinics on numerous occasions to the streets directly surrounding the community homeless shelter, allowing SMP to vaccinate individuals directly in their encampments. Through SMP's efforts starting in February 2021, 400 individuals experiencing homelessness have received at least one COVID-19 vaccine. Challenges encountered included low health literacy, lack of established rapport and trust, low vaccine confidence, difficulty verifying patients' vaccination status, difficulty obtaining sufficient information from patients to create a record in the Arizona State Immunization Information System (ASIIS), monitoring patients post-vaccination, transporting vaccine supplies from encampment to encampment, and lack of patient awareness of the mobile vaccine clinic services. Despite challenges, SMP's outreach efforts have demonstrated the feasibility and importance of mobile public health services to reach homeless encampments, particularly mobile vaccination clinics in response to disease outbreaks, and the necessity of strategic partnerships with community agencies to effectively meet the needs of underserved populations.

Effect of an Innovative Immunization Practice Model to Improve Population Health: Results of the Project IMPACT Immunizations Scaled Demonstration.

Background: U.S. adult vaccination rates remain low. Community pharmacists have skills and opportunity to improve this shortcoming. This study sought to evaluate an innovative practice model on identification of unmet vaccination needs and their resolution. Methods: This prospective, multi-site, multi-state, observational study was conducted in 22 community pharmacy practices in Iowa and Washington. Adults receiving influenza vaccination, medication therapy review, prescriptions for diabetes or cardiovascular disease, or another clinical encounter with a participating pharmacist from December 2017 through November 2019 were included. Pharmacists reviewed vaccination forecasts generated by clinical decision support technology based on their state immunization information system (IIS) to identify unmet vaccination needs, educate patients, and improve vaccination rates. The primary outcomes were numbers of vaccination forecast reviews, patients educated, unmet vaccination needs identified and resolved, and vaccinations administered. Secondary outcomes included numbers of vaccination declinations; times a forecasted vaccine was not recommended because a contraindication was identified by the pharmacist; and times the patients declined a forecasted vaccine due to self-reported vaccination despite lack of documentation in the state IIS. Descriptive statistics were calculated. Results: Pharmacists reviewed vaccination forecasts for 6,234 patients. The vaccination forecasts predicted there were 11,789 vaccinations needed (1.9 per person). 6,405 of the 11,789 unmet vaccination needs (54.3%) were fulfilled during the study period, including 60% on the same day. Of the forecasted needs, 1,085 (9.2%) were found to be previously administered and 59 (0.5%) contraindicated. The remaining patients received information about their personal vaccination needs and recommendations to be vaccinated. Conclusion: Availability of vaccination histories during patient encounters allowed pharmacists to identify and resolve adult vaccination needs in independent and chain community practice settings.

Association between pertussis vaccination coverage and other sociodemographic factors and pertussis incidence using surveillance data

Routine vaccination with pertussis vaccines has been successful in driving down pertussis mortality and morbidity globally. Despite high vaccination coverage, countries such as Australia, USA, and UK have experienced increase in pertussis activity over the last few decades. This may be due to local pockets of low vaccination coverage that result in persistence of pertussis in the population and occasionally lead to large outbreaks. The objective of this study was to characterize the association between pertussis vaccination coverage and sociodemographic factors and pertussis incidence at the school district level in King County, Washington, USA. We used monthly pertussis incidence data for all ages reported to the Public Health Seattle and King County between January 1, 2010 and December 31, 2017 to obtain school district level pertussis incidence. We obtained immunization data from the Washington State Immunization Information System to estimate school-district level vaccination coverage as proportion of 19–35 month old children fully vaccinated with ≥4 doses of the Diphtheria-Tetanus-acellular-Pertussis (DTaP) vaccine in a school district. We used two methods to quantify the effects of vaccination coverage on pertussis incidence: an ecological vaccine model and an endemic–epidemic model. Even though the effect of vaccination is modeled differently in the two approaches, both models can be used to estimate the association between vaccination coverage and pertussis incidence. Using the ecological vaccine model, we estimated the vaccine effectiveness of 4 doses of Diphtheria-Tetanus-acellular-Pertussis vaccine to be 83% (95% credible interval: 63%, 95%). In the endemic–epidemic model, under-vaccination was statistically significantly associated with epidemic risk of pertussis (adjusted Relative Risk, aRR: 2.76; 95% confidence interval: 1.44, 16.6). Household size and median income were statistically significantly associated with endemic pertussis risk. The endemic–epidemic model suffers from ecological bias, whereas the ecological vaccine model provides less biased and more interpretable estimates of epidemiological parameters, such as DTaP vaccine effectiveness, for each school district.

School-Based Interventions to Increase Student COVID-19 Vaccination Coverage in Public School Populations with Low Coverage — Seattle, Washington, December 2021–June 2022

COVID-19 can lead to severe outcomes in children (1). Vaccination decreases risk for COVID-19 illness, severe disease, and death (2). On December 13, 2020, CDC recommended COVID-19 vaccination for persons aged ≥16 years, with expansion on May 12, 2021, to children and adolescents (children) aged 12-15 years, and on November 2, 2021, to children aged 5-11 years (3). As of March 8, 2023, COVID-19 vaccination coverage among school-aged children remained low nationwide, with 61.7% of children aged 12-17 years and approximately one third (32.7%) of those aged 5-11 years having completed the primary series (3). Intention to receive COVID-19 vaccine and vaccination coverage vary by demographic characteristics, including race and ethnicity and socioeconomic status (4-6). Seattle Public Schools (SPS) implemented a program to increase COVID-19 vaccination coverage during the 2021-22 school year, focusing on children aged 5-11 years during November 2021-June 2022, with an added focus on populations with low vaccine coverage during January 2022-June 2022.† The program included strategic messaging, school-located vaccination clinics, and school-led community engagement. Vaccination data from the Washington State Immunization Information System (WAIIS) were analyzed to examine disparities in COVID-19 vaccination by demographic and school characteristics and trends over time. In December 2021, 56.5% of all SPS students, 33.7% of children aged 5-11 years, and 81.3% of children aged 12-18 years had completed a COVID-19 primary vaccination series. By June 2022, overall series completion had increased to 80.3% and was 74.0% and 86.6% among children aged 5-11 years and 12-18 years, respectively. School-led vaccination programs can leverage community partnerships and relationships with families to improve COVID-19 vaccine access and coverage.

Assessing the impact of a pharmacy-provided personalized vaccination recommendation on immunization rates of adolescents

BackgroundAdolescents should receive timely doses of recommended vaccinations. The coronavirus disease 2019 (COVID-19) vaccination approval for adolescents presented an opportunity for community pharmacists to address gaps in adolescent immunization schedules. ObjectivesThe objectives of this research were to (1) identify adolescent immunization gaps, (2) identify number of patients receiving recommended vaccination(s) at the community pharmacy, and (3) determine how many vaccinations were administered after the intervention. MethodsThree pharmacies conducted the prospective intervention. Adolescents aged 11-17 years initiating the Pfizer-BioNTech COVID-19 vaccination series were eligible to receive a personalized vaccination recommendation (PVR), which included up to 3 other vaccinations. State immunization information systems were assessed after dose 1 of the COVID-19 vaccine to create the recommendation(s) and reassessed 6 months after providing the PVR for accepted recommendations. Patient demographics and number of vaccinations administered were assessed using descriptive statistics. ResultsOf the 225 adolescents who received COVID-19 vaccine dose 1, 74.7%, 75.1%, and 83.1% were indicated to receive tetanus, diphtheria, and acellular pertussis (Tdap), meningococcal conjugate (MenACWY), or human papillomavirus (HPV) vaccine, respectively. Thirty-three (14.7%) adolescents were up to date on all 3 vaccinations assessed. Of the 225 adolescents, 180 returned to the same location for COVID-19 vaccine dose 2 and received a PVR. Forty-two caregivers reported that their adolescent previously received 1 or more of the recommended vaccinations, indicating that state immunization information systems were inaccurate. Six months after the PVRs were given, 24 vaccinations had been administered. ConclusionsMost adolescents presenting for a COVID-19 vaccine were indicated, according to state immunization information systems, to receive at least 1 additional vaccination. After pharmacist-provided PVR and education, vaccine uptake occurred. Considering caregiver-reported inaccuracies, pharmacists should be cognizant of potential discrepancies when providing PVRs. In addition, this study highlights the value of a state immunization information system.

Casirivimab/imdevimab treatment for outpatient COVID-19 during a SARS-CoV-2 B1.617.2 (Delta) surge at a community hospital.

Vaccination status has been shown to be linked to patient-centered outcomes in those with COVID-19. However, minimal data have explored the relationship between vaccination status and representation rates after receiving monoclonal antibodies (MABs) the Delta strain of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) in a community setting. The authors sought to determine if there was a difference in patient-centered outcomes between those who were vaccinated and unvaccinated after the administration of casirivimab/imdevimab for mild-to-moderate COVID-19 during the time when the Delta strain was most prevalent. A convenience sample of consecutive adults given casirivimab/imdevimab at either an outpatient infusion center or within the emergency department (ED) were included in analysis. Patient demographics, authorized-use qualifiers from the emergency use authorization (EUA), baseline vital signs at the time of infusion, representation rates to a healthcare provider within the hospital's network, and any admissions to the hospital following infusion were all collected from the patient's electronic medical record. Vaccination status was confirmed in both the patient's electronic medical record and the Arizona State Immunization Information System (ASIIS). Analysis was conducted utilizing descriptive statistics, the Mann-Whitney U test for continuous data, and the chi-squared analysis for nominal data. In total, 743 patients were included in the study, with 585 being unvaccinated and 158 being vaccinated at the time of administration. Those in the vaccinated group were more likely to be older (60.0 vs. 55.0years; p<0.001) and to have a history of diabetes (18.4% vs. 11.3%; p=0.02), hypertension (39.9% vs. 28.5%; p=0.006), immunosuppression (7.0% vs. 1.4%; p<0.001), and chronic kidney disease (7.0% vs. 3.4%; p=0.05). In the entire sample, 105 (14.1%) patients had an unexpected return visit to either the ED or urgent care at 28days, with 17 (2.3%) requiring hospitalization. Patients who were vaccinated were more likely to represent for care after casirivimab/imdevimab infusion (20.3% vs. 12.5%; p=0.01), but no difference was noted in hospitalization rates between the two groups (18.8% vs. 15.1%; p=0.15). MAB therapy with casirivimab/imdevimab for the outpatient treatment of mild-to-moderate COVID-19 was associated with a low rate of hospitalization. However, those who were vaccinated were more likely to present for unexpected return care at either the ED or urgent care within 28days of the initial infusion.

Human papillomavirus vaccination uptake among childhood cancer survivors in Western New York.

The risk of human papillomavirus (HPV)-associated cancers is significantly higher among survivors of a childhood cancer compared to the general population. Despite this, their HPV vaccine uptake rates are lower. We examined factors related to HPV vaccine uptake among childhood cancer survivors from Western New York over 13years following the introduction of HPV vaccines. Retrospective review of patients diagnosed with invasive or noninvasive cancerous conditions at age 9 or younger treated at Roswell Park Oishei Children's Cancer and Blood Disorder Program. We matched vaccine date information for patients aged 9-26years between 2006 and 2020 from the New York State Immunization Information System. Demographic and cancer-related information was abstracted from electronic medical records. Cumulative vaccine uptake was assessed by Kaplan-Meier and Cox proportional hazards regression models. A total of 284 patients were included in the analyses. Most were non-Hispanic/White (80.3%) and resided in a metropolitan area (81.7%). Approximately half had leukemia or lymphoma (54.9%), and most received chemotherapy. Females were more likely to initiate the HPV vaccine and did so sooner (median=5.5years) than males (median=5.7years; log-rank p=.301). Patients who were older at vaccine eligibility and males who received blood product transfusions were significantly less likely to initiate the HPV vaccine. While rates of HPV vaccine initiation have been increasing with time among childhood cancer survivors, they remain low overall, with differences seen by treatment and diagnosis. Our findings support the need for further research to optimize HPV vaccine delivery in cancer care.

COVID-19-Associated Hospitalizations Among Vaccinated and Unvaccinated Adults 18 Years or Older in 13 US States, January 2021 to April 2022

Understanding risk factors for hospitalization in vaccinated persons and the association of COVID-19 vaccines with hospitalization rates is critical for public health efforts to control COVID-19. To determine characteristics of COVID-19-associated hospitalizations among vaccinated persons and comparative hospitalization rates in unvaccinated and vaccinated persons. From January 1, 2021, to April 30, 2022, patients 18 years or older with laboratory-confirmed SARS-CoV-2 infection were identified from more than 250 hospitals in the population-based COVID-19-Associated Hospitalization Surveillance Network. State immunization information system data were linked to cases, and the vaccination coverage data of the defined catchment population were used to compare hospitalization rates in unvaccinated and vaccinated individuals. Vaccinated and unvaccinated patient characteristics were compared in a representative sample with detailed medical record review; unweighted case counts and weighted percentages were calculated. Laboratory-confirmed COVID-19-associated hospitalization, defined as a positive SARS-CoV-2 test result within 14 days before or during hospitalization. COVID-19-associated hospitalization rates among vaccinated vs unvaccinated persons and factors associated with COVID-19-associated hospitalization in vaccinated persons were assessed. Using representative data from 192 509 hospitalizations (see Table 1 for demographic information), monthly COVID-19-associated hospitalization rates ranged from 3.5 times to 17.7 times higher in unvaccinated persons than vaccinated persons regardless of booster dose status. From January to April 2022, when the Omicron variant was predominant, hospitalization rates were 10.5 times higher in unvaccinated persons and 2.5 times higher in vaccinated persons with no booster dose, respectively, compared with those who had received a booster dose. Among sampled cases, vaccinated hospitalized patients with COVID-19 were older than those who were unvaccinated (median [IQR] age, 70 [58-80] years vs 58 [46-70] years, respectively; P < .001) and more likely to have 3 or more underlying medical conditions (1926 [77.8%] vs 4124 [51.6%], respectively; P < .001). In this cross-sectional study of US adults hospitalized with COVID-19, unvaccinated adults were more likely to be hospitalized compared with vaccinated adults; hospitalization rates were lowest in those who had received a booster dose. Hospitalized vaccinated persons were older and more likely to have 3 or more underlying medical conditions and be long-term care facility residents compared with hospitalized unvaccinated persons. The study results suggest that clinicians and public health practitioners should continue to promote vaccination with all recommended doses for eligible persons.

Sustained Management of COVID-19: Doing More of What Works to Control Future Surges.

Sustained Management of COVID-19: Doing More of What Works to Control Future Surges.

Evaluating vaccination coverage and timeliness in American Indian/Alaska Native and non-Hispanic White children using state immunization information system data, 2015-2017

Comprehensive estimates of vaccination coverage and timeliness of vaccine receipt among American Indian/Alaska Native (AI/AN) children in the United States are lacking. This study’s objectives were to quantify vaccination coverage and timeliness, as well as the proportion of children with specific undervaccination patterns, among AI/AN and non-Hispanic White (NHW) children ages 0–24 months in Montana, a large and primarily rural U.S. state. Data from Montana’s immunization information system (IIS) for children born 2015–2017 were used to calculate days undervaccinated for all doses of seven recommended vaccine series. After stratifying by race/ethnicity, up-to-date coverage at key milestone ages and the proportion of children demonstrating specific patterns of undervaccination were reported. Among n = 3,630 AI/AN children, only 23.1% received all recommended vaccine doses on-time (i.e., zero days undervaccinated), compared to 40.4% of n = 18,022 NHW children (chi-square p < 0.001). A greater proportion of AI/AN children were delayed at each milestone age, resulting in lower overall combined 7-vaccine series completion, by age 24 months (AI/AN: 56.6%, NHW: 64.3%, chi-square p < 0.001). As compared with NHW children, a higher proportion of AI/AN children had undervaccination patterns suggestive of structural barriers to accessing immunization services and delayed starts to vaccination. More than three out of four AI/AN children experienced delays in vaccination or were missing doses needed to complete recommended vaccine series. Interventions to ensure on-time initiation of vaccine series at age 2 months, as well initiatives to encourage completion of multi-dose vaccine series, are needed to reduce immunization disparities and increase vaccination coverage among AI/AN children in Montana.

Evidenced-Based Approaches States and Territories Can Implement to Advance Adult Immunization Uptake During the COVID-19 Pandemic and Beyond.

Evidenced-Based Approaches States and Territories Can Implement to Advance Adult Immunization Uptake During the COVID-19 Pandemic and Beyond.

Monitoring vaccine safety using the vaccine safety Datalink: Assessing capacity to integrate data from Immunization Information systems

BackgroundThe Vaccine Safety Datalink (VSD) uses vaccination data from electronic health records (EHR) at eight integrated health systems to monitor vaccine safety. Accurate capture of data from vaccines administered outside of the health system is critical for vaccine safety research, especially for COVID-19 vaccines, where many are administered in non-traditional settings. However, timely access and inclusion of data from Immunization Information Systems (IIS) into VSD safety assessments is not well understood. MethodsWe surveyed the eight data-contributing VSD sites to assess: 1) status of sending data to IIS; 2) status of receiving data from IIS; and 3) integration of IIS data into the site EHR. Sites reported separately for COVID-19 vaccination to capture any differences in capacity to receive and integrate data on COVID-19 vaccines versus other vaccines. ResultsAll VSD sites send data to and receive data from their state IIS. All eight sites (100%) routinely integrate IIS data for COVID-19 vaccines into VSD research studies. Six sites (75%) also routinely integrate all other vaccination data; two sites integrate data from IIS following a reconciliation process, which can result in delays to integration into VSD datasets. ConclusionsCOVID-19 vaccines are being administered in a variety of non-traditional settings, where IIS are commonly used as centralized reporting systems. All eight VSD sites receive and integrate COVID-19 vaccine data from IIS, which positions the VSD well for conducting quality assessments of vaccine safety. Efforts to improve the timely receipt of all vaccination data will improve capacity to conduct vaccine safety assessments within the VSD.

Influenza Vaccinations During the COVID-19 Pandemic - 11 U.S. Jurisdictions, September-December 2020.

Influenza causes considerable morbidity and mortality in the United States. Between 2010 and 2020, an estimated 9-41 million cases resulted in 140,000-710,000 hospitalizations and 12,000-52,000 deaths annually (1). As the United States enters the 2021-22 influenza season, the potential impact of influenza illnesses is of concern given that influenza season will again coincide with the ongoing COVID-19 pandemic, which could further strain overburdened health care systems. The Advisory Committee on Immunization Practices (ACIP) recommends routine annual influenza vaccination for the 2021-22 influenza season for all persons aged ≥6 months who have no contraindications (2). To assess the potential impact of the COVID-19 pandemic on influenza vaccination coverage, the percentage change between administration of at least 1 dose of influenza vaccine during September-December 2020 was compared with the average administered in the corresponding periods in 2018 and 2019. The data analyzed were reported from 11 U.S. jurisdictions with high-performing state immunization information systems.* Overall, influenza vaccine administration was 9.0% higher in 2020 compared with the average in 2018 and 2019, combined. However, in 2020, the number of influenza vaccine doses administered to children aged 6-23 months and children aged 2-4 years, was 13.9% and 11.9% lower, respectively than the average for each age group in 2018 and 2019. Strategic efforts are needed to ensure high influenza vaccination coverage among all age groups, especially children aged 6 months-4 years who are not yet eligible to receive a COVID-19 vaccine. Administration of influenza vaccine and a COVID-19 vaccine among eligible populations is especially important to reduce the potential strain that influenza and COVID-19 cases could place on health care systems already overburdened by COVID-19.