Immunization Practices Recommends Research Articles

Preventing Influenza Virus Infection and Severe Influenza Among Pregnant People and Infants.

The landscape of research on the benefits of influenza vaccines and antivirals to protect pregnant persons and infants has increased in recent years, while influenza vaccination rates and antiviral usage have declined. Pregnant people and infants <6 months of age are at increased risk of hospitalization with influenza, making protection of this population essential. Maternal influenza vaccination at any time during pregnancy is the best way to reduce the risk of influenza and severe influenza in both pregnant people and their infants <6 months of age. Influenza antiviral medications for pregnant people and infants are also recommended as early as possible if influenza is confirmed or suspected. This report will update on the current research on the benefits of influenza vaccination during pregnancy and influenza antiviral medication for the pregnant person and infant, current Advisory Committee on Immunization Practices recommendations for influenza vaccination in pregnancy and vaccination coverage rates, current influenza antiviral medication guidance and usage rates in pregnancy and among infants, and future directions for influenza pregnancy research. With over half a century of maternal influenza vaccination in the United States, we have improved protection for pregnant persons and infants against influenza, but we still have room for improvement and optimization with new challenges to overcome following the COVID-19 pandemic. By continuing to fill research gaps and increase vaccination coverage and antiviral usage, there is potential for significant reductions in the domestic and global burden of influenza in pregnant persons and infants.

Influenza and COVID-19 Vaccination Coverage Among Health Care Personnel - National Healthcare Safety Network, United States, 2023-24 Respiratory Virus Season.

The Advisory Committee on Immunization Practices (ACIP) recommends that health care personnel receive an annual influenza vaccine. In September 2023, ACIP recommended that everyone aged ≥6 months receive a 2023-2024 COVID-19 vaccine. Health care facilities, including acute care hospitals and nursing homes, report vaccination of health care personnel against influenza and COVID-19 to CDC's National Healthcare Safety Network (NHSN). During October 2023-March 2024, NHSN defined up-to-date COVID-19 vaccination as receipt of a 2023-2024 COVID-19 vaccine. This analysis describes influenza and 2023-2024 COVID-19 vaccination coverage among health care personnel working in acute care hospitals and nursing homes during the 2023-24 respiratory virus season (October 1, 2023-March 31, 2024). Influenza vaccination coverage was 80.7% among health care personnel at acute care hospitals and 45.4% among health care personnel at nursing homes. Coverage of 2023-2024 COVID-19 vaccination was 15.3% among health care personnel at acute care hospitals and 10.5% among health care personnel at nursing homes. Respiratory viral diseases including influenza and COVID-19 pose risks to health care personnel in U.S. health care settings, and vaccination of health care personnel is an effective strategy for maintaining a healthy workforce and improving health care system resiliency.

On-time childhood vaccination before and during the COVID-19 pandemic in seven communities: Findings from the New Vaccine Surveillance Network

BackgroundThe COVID-19 pandemic raised unprecedented challenges to vaccinating children. This multi-center study aimed to compare on-time vaccination of children before and during the COVID-19 pandemic and identify key factors associated with on-time vaccination. MethodsThis study was conducted among children aged 0–6 years enrolled in the New Vaccine Surveillance Network at seven geographically diverse U.S. academic medical centers. Children with acute respiratory illness or acute gastroenteritis were enrolled from emergency department and inpatient settings; healthy control subjects were enrolled from primary care practices. Vaccination data were collected and verified from patient medical records, immunization information systems, and/or provider documentation. On-time vaccination according to Advisory Committee on Immunization Practices recommendations was compared between pre-pandemic (December 2018–February 2020) and pandemic (March 2020–August 2021) periods using bivariate and multivariable analyses, adjusting for key demographic, clinical, and study characteristics. ResultsA total of 24,713 children were included in the analytic sample (non-Hispanic 73.4 %; White 51.0 %; publicly insured 69.0 %). On-time vaccination declined between the pre-pandemic (67.3 %) and pandemic (65.4 %) periods (Adjusted Odds Ratio 0.89, 95 % CI 0.84–0.95). The largest declines were observed among children who were < 12 months, male, Black, publicly insured, or whose mothers had a high school-equivalent education or less. The pandemic impact also varied by vaccine type and study site. ConclusionsThis multi-center study revealed a relatively modest overall reduction in on-time vaccination, which may reflect multilevel efforts to address pandemic-associated challenges. However, some patient subgroups and sites experienced greater reductions in on-time vaccination, highlighting the importance of tailoring interventions to increase equitable vaccine delivery, access, and acceptance across populations and communities.

Use of 21-Valent Pneumococcal Conjugate Vaccine Among U.S. Adults: Recommendations of the Advisory Committee on Immunization Practices - United States, 2024.

On June 17, 2024, the Food and Drug Administration approved 21-valent pneumococcal conjugate vaccine (PCV) (PCV21; CAPVAXIVE; Merck Sharp & Dohme, LLC) for adults aged ≥18 years. PCV21 does not contain certain serotypes that are included in other licensed pneumococcal vaccines but adds eight new serotypes. The Advisory Committee on Immunization Practices (ACIP) recommends use of a PCV for all adults aged ≥65 years, as well as adults aged 19-64 years with certain risk conditions for pneumococcal disease if they have not received a PCV or whose vaccination history is unknown. Previously, options included either 20-valent PCV (PCV20; Prevnar20; Wyeth Pharmaceuticals, Inc.) alone or a 15-valent PCV (PCV15; VAXNEUVANCE; Merck Sharp & Dohme, LLC) in series with 23-valent pneumococcal polysaccharide vaccine (PPSV23; Pneumovax23; Merck Sharp & Dohme, LLC). Additional recommendations for use of PCV20 exist for adults who started their pneumococcal vaccination series with 13-valent PCV (PCV13; Prevnar13; Wyeth Pharmaceuticals, Inc.). The ACIP Pneumococcal Vaccines Work Group employed the Evidence to Recommendations framework to guide its deliberations on PCV21 vaccination among U.S. adults. On June 27, 2024, ACIP recommended a single dose of PCV21 as an option for adults aged ≥19 years for whom PCV is currently recommended. Indications for PCV have not changed from previous recommendations. This report summarizes evidence considered for these recommendations and provides clinical guidance for use of PCV21.

Immunity to Varicella Zoster Virus in Healthcare Workers: A Systematic Review and Meta-Analysis (2024).

Healthcare workers (HCWs) are occupationally exposed to varicella zoster virus (VZV), and their inappropriate vaccination status could contribute to an outbreak involving both professionals and the patients they care for, with a potential impact on the general population. Therefore, since 2007, the Advisory Committee on Immunization Practices (ACIP) recommends that all HCWs have evidence of immunity against varicella. The present meta-analysis was therefore designed to collect the available evidence on the seronegative status of VZV among HCWs. PubMed, Scopus, and Embase databases were searched without backward limit for articles reporting on the seroprevalence of VZV among HCWs, and all articles meeting the inclusion criteria were included in a random-effect meta-analysis model. From 1744 initial entries, a total of 58 articles were included in the quantitative analysis (publication range: 1988 to 2024), for a pooled sample of 71,720 HCWs. Moreover, the included studies reported on seroprevalence data on measles (N = 36,043 HCWs) and rubella (N = 22,086 HCWs). Eventually, the pooled seronegative status for VZV was estimated to be 5.72% (95% confidence interval [95% CI] 4.59 to 7.10) compared to 6.91% (95% CI 4.79 to 9.87) for measles and 7.21% (5.36 to 9.64) for rubella, with a greater risk among subjects younger than 30 years at the time of the survey (risk ratio [RR] 1.434, 95% CI 1.172 to 1.756). Interestingly, medical history of either VZV infection/vaccination had low diagnostic performances (sensitivity 76.00%; specificity 60.12%; PPV of 96.12% but PNV of 18.64%). In summary, the available data suggest that newly hired HCWs are increasingly affected by low immunization rates for VZV but also for measles and rubella, stressing the importance of systematically testing test newly hired workers for all components of the measles-pertussis-rubella-varicella vaccine.

National Vaccination Coverage Among Adolescents Aged 13-17 Years - National Immunization Survey-Teen, United States, 2023.

Based on safety and efficacy data, vaccinations are the best defense to protect persons and communities from serious vaccine-preventable diseases. The Advisory Committee on Immunization Practices recommends routine vaccination of adolescents aged 11-12 years with three vaccines including tetanus, diphtheria, and acellular pertussis vaccine; quadrivalent meningococcal conjugate vaccine; and human papillomavirus vaccine. CDC analyzed data from the 2023 National Immunization Survey-Teen for 16,658 adolescents aged 13-17 years (born during January 2005-December 2010) to assess vaccination coverage in 2023, recent trends in coverage by birth year, and trends in coverage by eligibility for the Vaccines for Children (VFC) program and birth year. In 2023, coverage with all routine vaccines recommended for adolescents was similar to coverage in 2022. Vaccination coverage among VFC-eligible adolescents was generally stable during the COVID-19 pandemic, except for a decrease in the percentage of VFC-eligible adolescents who were up to date with HPV vaccination by age 13 years among those born in 2010 compared with those born in 2007. Whereas coverage differences were found between VFC-eligible and non-VFC-eligible adolescents before the COVID-19 pandemic, coverage was similar among the most recent birth years in the survey. Providers should make strong recommendations for all routine vaccines and review adolescent vaccination records to verify if adolescents are up to date with all recommended vaccines.

Implementing a meningococcal B vaccination multimedia educational campaign for university students

BackgroundMeningococcal serogroup B (MenB) is the leading cause of potentially fatal meningococcal disease among U.S. older adolescents and young adults; college students are at increased risk. Although the Advisory Committee on Immunization Practices recommends that healthy 16- to 23-year-olds may be vaccinated against MenB, MenB vaccination coverage is low. ObjectiveThis study investigated the impact of a comprehensive multimedia MenB vaccine educational campaign on 2-dose MenB vaccine series initiation among college students. MethodsWe implemented a 6-week-long (October 11, 2021-November 19, 2021) educational intervention via a prospective trial on a university campus (the intervention campus), including video broadcasting, student-led campus programming, and printed materials. The control campus was a different university in the same urban setting. ResultsDuring baseline period 1 (August 26, 2019-November 15, 2019), 2 students on the intervention campus and 3 students on the control campus initiated the MenB vaccination series; 1 student initiated the series on the intervention campus during baseline period 2 (August 27, 2021-October 8, 2021). At least 83 students were exposed to the campaign during the intervention period (October 11, 2021-November 19, 2021). No students initiated the MenB vaccination series during the intervention period, although 1 student completed the vaccination series. ConclusionThe campaign did not influence MenB vaccination initiation on the university campus.

United States Physicians' Knowledge, Attitudes, and Practices Regarding Meningococcal Vaccination for Healthy Adolescents and Young Adults

PurposeThe United States Advisory Committee on Immunization Practices (ACIP) recommends vaccination against meningococcal serogroups A, C, W, and Y (MenACWY) for all 11–12-year-olds, with a booster dose for 16-year-olds, and against meningococcal serogroup B (MenB) for 16–23-year-olds under shared clinical decision-making (SCDM). However, uptake of the MenB vaccine and the MenACWY booster dose is low. This study investigated United States physicians' knowledge, attitudes, and practices regarding recommending MenB and MenACWY vaccines to non-high-risk older adolescents and young adults. MethodsAn online survey was conducted in April–May 2022 among pediatricians, family physicians (FPs), general practitioners (GPs), and internists who had recommended the MenB and/or the MenACWY vaccine(s) to at least one 16–23-year-old in the past year. ResultsAmong 407 participants, 50% correctly identified MenB as the leading cause of meningococcal disease among adolescents and young adults. Furthermore, 46% of physicians (47% of pediatricians, 40% of FPs and GPs, 53% of internists) answered correctly that MenB vaccination is recommended under SCDM, and 82% of physicians (96% of pediatricians, 70% of FPs and GPs, 65% of internists) answered correctly that MenACWY vaccination is routinely recommended. Among MenB-vaccinators, 78% reported having received some training or other information on implementing SCDM, and 65% rated recommending MenB vaccination as very important. DiscussionKnowledge gaps, which varied by specialty, were identified regarding meningococcal disease and vaccine recommendations, particularly regarding MenB. Targeted education of physicians may facilitate discussions about MenB vaccination.

Advisory Committee on Immunization Practices Recommended Immunization Schedule for Adults Aged 19 Years or Older - United States, 2024.

At its October 2023 meeting, the Advisory Committee on Immunization Practices* (ACIP) approved the Recommended Adult Immunization Schedule for Ages 19 Years or Older, United States, 2024. The adult immunization schedule, which can be found on the CDC immunization schedule website (https://www.cdc.gov/vaccines/schedules), is published annually to consolidate and summarize updates to ACIP recommendations on the vaccination of adults and to assist health care providers in implementing current ACIP recommendations. The 2024 immunization schedule includes several changes to the cover page, tables, notes, and appendix from the 2023 immunization schedule.† In addition, the 2024 adult immunization schedule includes a new addendum section that summarizes new or updated ACIP recommendations that will occur before the next annual update to the adult immunization schedule. Health care providers are advised to use the cover page, tables, notes, appendix, and addendum together to determine recommended vaccinations for patient populations.

Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger - United States, 2024.

At its October 2023 meeting, the Advisory Committee on Immunization Practices* (ACIP) approved the Recommended Child and Adolescent Immunization Schedule for Ages 18 Years or Younger, United States, 2024. The child and adolescent immunization schedule, which can be found on the CDC immunization schedule website (https://www.cdc.gov/vaccines/schedules), is published annually to consolidate and summarize updates to ACIP recommendations on the vaccination of children and adolescents and to assist health care providers in implementing current ACIP recommendations. The 2024 immunization schedule includes several changes to the cover page, tables, notes, and appendix from the 2023 immunization schedule.† In addition, the 2024 child and adolescent immunization schedule includes a new addendum section to summarize new or updated ACIP recommendations that will occur before the next annual update to the child and adolescent immunization schedule. Health care providers are advised to use the cover page, tables, notes, appendix, and addendum together to identify the recommended immunizations for patient populations.

Influenza, Updated COVID-19, and Respiratory Syncytial Virus Vaccination Coverage Among Adults - United States, Fall 2023.

During the 2023-24 respiratory virus season, the Advisory Committee on Immunization Practices recommends influenza and COVID-19 vaccines for all persons aged ≥6 months, and respiratory syncytial virus (RSV) vaccine is recommended for persons aged ≥60 years (using shared clinical decision-making), and for pregnant persons. Data from the National Immunization Survey-Adult COVID Module, a random-digit-dialed cellular telephone survey of U.S. adults aged ≥18 years, are used to monitor influenza, COVID-19, and RSV vaccination coverage. By December 9, 2023, an estimated 42.2% and 18.3% of adults aged ≥18 years reported receiving an influenza and updated 2023-2024 COVID-19 vaccine, respectively; 17.0% of adults aged ≥60 years had received RSV vaccine. Coverage varied by demographic characteristics. Overall, approximately 27% and 41% of adults aged ≥18 years and 53% of adults aged ≥60 years reported that they definitely or probably will be vaccinated or were unsure whether they would be vaccinated against influenza, COVID-19, and RSV, respectively. Strong provider recommendations for and offers of vaccination could increase influenza, COVID-19, and RSV vaccination coverage. Immunization programs and vaccination partners are encouraged to use these data to understand vaccination patterns and attitudes toward vaccination in their jurisdictions to guide planning, implementation, strengthening, and evaluation of vaccination activities.

Nurse Practitioners’ and Physician Assistants’ Knowledge, Attitudes, and Practices Regarding Meningococcal Vaccination for Healthy Adolescents and Young Adults in the United States

The United States Advisory Committee on Immunization Practices recommends vaccination against meningococcal serogroups A, C, W, and Y for all 11- and 12-year-olds (with a booster dose at age 16) and against meningococcal serogroup B for 16- to 23-year-olds under shared clinical decision making. This study investigated knowledge, attitude, and practices among nurse practitioners and physician assistants regarding meningococcal vaccination. Although nurse practitioners and physician assistants play an important role in discussing and recommending vaccination, knowledge gaps regarding meningococcal disease and vaccination guidelines were identified. Targeted education may promote shared clinical decision making, improving access to meningococcal vaccination.

CDC Guidelines for the Prevention and Treatment of Anthrax, 2023.

Bacillus anthracis spores if resources become limited or a multidrug-resistant B. anthracis strain is used (Hendricks KA, Wright ME, Shadomy SV, et al.; Workgroup on Anthrax Clinical Guidelines. Centers for Disease Control and Prevention expert panel meetings on prevention and treatment of anthrax in adults. Emerg Infect Dis 2014;20:e130687; Meaney-Delman D, Rasmussen SA, Beigi RH, et al. Prophylaxis and treatment of anthrax in pregnant women. Obstet Gynecol 2013;122:885-900; Bradley JS, Peacock G, Krug SE, et al. Pediatric anthrax clinical management. Pediatrics 2014;133:e1411-36). Specifically, this report updates antimicrobial drug and antitoxin use for both postexposure prophylaxis (PEP) and treatment from these previous guidelines best practices and is based on systematic reviews of the literature regarding 1) in vitro antimicrobial drug activity against B. anthracis; 2) in vivo antimicrobial drug efficacy for PEP and treatment; 3) in vivo and human antitoxin efficacy for PEP, treatment, or both; and 4) human survival after antimicrobial drug PEP and treatment of localized anthrax, systemic anthrax, and anthrax meningitis. B. anthracis strain. In addition, these updated guidelines include new recommendations regarding special considerations for the diagnosis and treatment of anthrax meningitis, including comorbid, social, and clinical predictors of anthrax meningitis. The previously published CDC guidelines and recommendations described potentially beneficial critical care measures and clinical assessment tools and procedures for persons with anthrax, which have not changed and are not addressed in this update. In addition, no changes were made to the Advisory Committee on Immunization Practices recommendations for use of anthrax vaccine (Bower WA, Schiffer J, Atmar RL, et al. Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Recomm Rep 2019;68[No. RR-4]:1-14). The updated guidelines in this report can be used by health care providers to prevent and treat anthrax and guide emergency preparedness officials and planners as they develop and update plans for a wide-area aerosol release of B. anthracis.

Public health impact of the U.S. Scenario Modeling Hub

Beginning in December 2020, the COVID-19 Scenario Modeling Hub has provided quantitative scenario-based projections for cases, hospitalizations, and deaths, aggregated across up to nine modeling groups. Projections spanned multiple months into the future and provided timely information on potential impacts of epidemiological uncertainties and interventions. Projections results were shared with the public, public health partners, and the Centers for Disease Control COVID-19 Response Team. The projections provided insights on situational awareness and informed decision-making to mitigate COVID-19 disease burden (e.g., vaccination strategies). By aggregating projections from multiple modeling teams, the Scenario Modeling Hub provided rapidly synthesized information in times of great uncertainty and conveyed possible trajectories in the presence of emerging variants. Here we detail several use cases of these projections in public health practice and communication, including assessments of whether modeling results directly or indirectly informed public health communication or guidance. These include multiple examples where comparisons of projected COVID-19 disease outcomes under different vaccination scenarios were used to inform Advisory Committee for Immunization Practices recommendations. We also describe challenges and lessons learned during this highly beneficial collaboration.

Safety Monitoring of mRNA COVID-19 Vaccine Third Doses Among Children Aged 6 Months–5 Years — United States, June 17, 2022–May 7, 2023

As of May 7, 2023, CDC's Advisory Committee on Immunization Practices (ACIP) recommends that all children aged 6 months-5 years receive at least 1 age-appropriate bivalent mRNA COVID-19 vaccine dose. Depending on their COVID-19 vaccination history and history of immunocompromise, these children might also need additional doses* (1-3). Initial vaccine safety findings after primary series vaccination among children aged 6 months-5 years showed that transient local and systemic reactions were common whereas serious adverse events were rare (4). To characterize the safety of a third mRNA COVID-19 vaccine dose among children aged 6 months-5 years, CDC reviewed adverse events and health surveys reported to v-safe, a voluntary smartphone-based U.S. safety surveillance system established by CDC to monitor health after COVID-19 vaccination (https://vsafe.cdc.gov/en/) and the Vaccine Adverse Event Reporting System (VAERS), a U.S. passive vaccine safety surveillance system co-managed by CDC and the Food and Drug Administration (FDA) (https://vaers.hhs.gov/) (5). During June 17, 2022-May 7, 2023, approximately 495,576 children aged 6 months-4 years received a third dose (monovalent or bivalent) of Pfizer-BioNTech vaccine and 63,919 children aged 6 months-5 years received a third dose of Moderna vaccine.† A third mRNA COVID-19 vaccination was recorded for 2,969 children in v-safe; approximately 37.7% had no reported reactions, and among those for whom reactions were reported, most reactions were mild and transient. VAERS received 536 reports after a third dose of mRNA COVID-19 vaccine for children in these age groups; 98.5% of reports were nonserious and most (78.4%) were classified as a vaccination error.§ No new safety concerns were identified. Preliminary safety findings after a third dose of COVID-19 vaccine for children aged 6 months-5 years are similar to those after other doses. Health care providers can counsel parents and guardians of young children that most reactions reported after vaccination with Pfizer-BioNTech or Moderna vaccine were mild and transient and that serious adverse events are rare.

Epidemiologic Trends of Dengue in U.S. Territories, 2010-2020.

Dengue is one of the most common vectorborne flaviviral infections globally, with frequent outbreaks in tropical regions. In 2019 and 2020, the Pan American Health Organization reported approximately 5.5 million dengue cases from the Americas, the highest number on record. In the United States, local dengue virus (DENV) transmission has been reported from all U.S. territories, which are characterized by tropical climates that are highly suitable for Aedes species of mosquitoes, the vector that transmits dengue. Dengue is endemic in the U.S. territories of American Samoa, Puerto Rico, and the U.S. Virgin Islands (USVI). Dengue risk in Guam and the Commonwealth of the Northern Mariana Islands is considered sporadic or uncertain. Despite all U.S. territories reporting local dengue transmission, epidemiologic trends over time have not been well described. 2010-2020. State and territorial health departments report dengue cases to CDC through ArboNET, the national arboviral surveillance system, which was developed in 2000 to monitor West Nile virus infections. Dengue became nationally notifiable in ArboNET in 2010. Dengue cases reported to ArboNET are categorized using the 2015 Council of State and Territorial Epidemiologists case definition. In addition, DENV serotyping is performed at CDC's Dengue Branch Laboratory in a subset of specimens to support identification of circulating DENV serotypes. During 2010-2020, a total of 30,903 dengue cases were reported from four U.S. territories to ArboNET. Puerto Rico reported the highest number of dengue cases (29,862 [96.6%]), followed by American Samoa (660 [2.1%]), USVI (353 [1.1%]), and Guam (28 [0.1%]). However, annual incidence rates were highest in American Samoa with 10.2 cases per 1,000 population in 2017, followed by Puerto Rico with 2.9 in 2010 and USVI with 1.6 in 2013. Approximately one half (50.6%) of cases occurred among persons aged <20 years. The proportion of persons with dengue who were hospitalized was high in three of the four territories: 45.5% in American Samoa, 32.6% in Puerto Rico, and 32.1% in Guam. In Puerto Rico and USVI, approximately 2% of reported cases were categorized as severe dengue. Of all dengue-associated deaths, 68 (0.2%) were reported from Puerto Rico; no deaths were reported from the other territories. During 2010-2020, DENV-1 and DENV-4 were the predominant serotypes in Puerto Rico and USVI. U.S. territories experienced a high prevalence of dengue during 2010-2020, with approximately 30,000 cases reported, and a high incidence during outbreak years. Children and adolescents aged <20 years were disproportionately affected, highlighting the need for interventions tailored for this population. Ongoing education about dengue clinical management for health care providers in U.S. territories is important because of the high hospitalization rates reported. Dengue case surveillance and serotyping can be used to guide future control and prevention measures in these areas. The Advisory Committee on Immunization Practices recommends vaccination with Dengvaxia for children aged 9-16 years with evidence of previous dengue infection and living in areas where dengue is endemic. The recommendation for the dengue vaccine offers public health professionals and health care providers a new intervention for preventing illness and hospitalization in the age group with the highest burden of disease in the four territories (Paz Bailey G, Adams L, Wong JM, et al. Dengue Vaccine: Recommendations of the Advisory Committee on Immunization Practices, United States, 2021. MMWR Recomm Rep 2021;70[No. RR-6]). American Samoa, Puerto Rico, and USVI are all considered endemic areas and persons residing in these areas are eligible for the new dengue vaccine. Persons aged 9-16 years in those jurisdictions with laboratory evidence of previous dengue infection can receive the dengue vaccine and benefit from a reduced risk for symptomatic disease, hospitalization, or severe dengue. Health care providers in these areas should be familiar with the eligibility criteria and recommendations for vaccination to reduce the burden of dengue among the group at highest risk for symptomatic illness. Educating health care providers about identification and management of dengue cases can improve patient outcomes and improve surveillance and reporting of dengue cases.

Secondary Cases of Invasive Disease Caused by Encapsulated and Nontypeable Haemophilus influenzae - 10 U.S. Jurisdictions, 2011-2018.

Haemophilus influenzae (Hi) can cause meningitis and other serious invasive disease. Encapsulated Hi is classified into six serotypes (a-f) based on chemical composition of the polysaccharide capsule; unencapsulated strains are termed nontypeable Hi (NTHi). Hi serotype b (Hib) was the most common cause of bacterial meningitis in children in the pre-Hib vaccine era, and secondary transmission of Hi among children (e.g., to household contacts and in child care facilities) (1,2) led to the Advisory Committee on Immunization Practices (ACIP) recommendation for antibiotic chemoprophylaxis to prevent Hib disease in certain circumstances.* High Hib vaccination coverage since the 1990s has substantially reduced Hib disease, and other serotypes now account for most Hi-associated invasive disease in the United States (3). Nevertheless, CDC does not currently recommend chemoprophylaxis for contacts of persons with invasive disease caused by serotypes other than Hib and by NTHi (non-b Hi). Given this changing epidemiology, U.S. surveillance data were reviewed to investigate secondary cases of invasive disease caused by Hi. The estimated prevalence of secondary transmission was 0.32% among persons with encapsulated Hi disease (≤60 days of one another) and 0.12% among persons with NTHi disease (≤14 days of one another). Isolates from all Hi case pairs were genetically closely related, and all patients with potential secondary infection had underlying medical conditions. These results strongly suggest that secondary transmission of non-b Hi occurs. Expansion of Hi chemoprophylaxis recommendations might be warranted to control invasive Hi disease in certain populations in the United States, but further analysis is needed to evaluate the potential benefits against the risks, such as increased antibiotic use.

Health care provider knowledge around shared clinical decision-making regarding HPV vaccination of adults aged 27-45 years in the United States.

The Advisory Committee on Immunization Practices (ACIP) recommends shared clinical decision-making (SCDM) regarding HPV vaccination for adults aged 27-45years who are not adequately vaccinated. The objective of this survey was to understand physician knowledge, attitudes, and practices regarding HPV vaccination in this age group. An online survey was administered in June 2021 to physicians who reported practicing internal medicine, family medicine, or obstetrics and gynecology (targeted N=250 in each practice specialty), selected randomly from potentially eligible physicians from a panel of 2 million U.S. health care providers. In total, 753 physicians participated in the survey: 33.3% practiced internal medicine, 33.1% practiced family medicine, and 33.6% practiced obstetrics/gynecology; 62.5% were male and mean physician age was 52.7years. Despite the COVID-19 pandemic, at least a third of participating physicians in each practice specialty reported having more HPV vaccine SCDM discussions with patients aged 27-45years in the past 12months. While a majority of physicians (79.7%) reported being aware of the SCDM recommendation for adults in this age group, only half of physicians answered an objective knowledge question about SCDM recommendations correctly. Findings suggest that there are physician knowledge gaps related to SCDM for HPV vaccination. To improve access to HPV vaccination for people most likely to benefit, increasing availability and use of decision aids to support SCDM discussions might help healthcare providers and patients jointly make the most informed decisions about HPV vaccination.

Gaps in Prenatal Hepatitis B Screening and Management of HBsAg Positive Pregnant Persons in the U.S., 2015–2020

The Advisory Committee for Immunization Practices (ACIP) recommends testing all pregnant women for hepatitis B surface antigen (HBsAg) and testing HBsAg-positive pregnant women for hepatitis B virus deoxyribonucleic acid (HBV DNA). HBsAg-positive pregnant persons are recommended by the American Association for the Study of Liver Diseases to receive regular monitoring, including alanine transaminase (ALT) and HBV DNA and antiviral therapy for active hepatitis and to prevent perinatal HBV transmission if HBV DNA level is >200,000 IU/mL. Using Optum Clinformatics Data Mart Database claims data, pregnant women who received HBsAg testing and HBsAg-positive pregnant persons who received HBV DNA and alt testing and antiviral therapy during pregnancy and after delivery during January 1, 2015-December 31, 2020 were analyzed. Among 506,794 pregnancies, 14.6% did not receive HBsAg testing. Pregnant women more likely to receive testing for HBsAg (p<0.01) were persons aged ≥20 years, were Asian, had >1 child, or received education beyond high school. Among the 0.28% (1,437) pregnant women who tested positive for hepatitis B surface antigen, 46% were Asian. The proportion of HBsAg-positive pregnant women who received HBV DNA testing during pregnancy and in the 12 months after delivery was 44.3% and 28.6%, respectively; the proportion that received hepatitis B e antigen was 31.6% and 12.7%, respectively; the proportion that received ALT testing was 67.4% and 47%, respectively; and the proportion that received HBV antiviral therapy was 7% and 6.2%, respectively. This study suggests that as many as half a million (∼14%) pregnant persons who gave birth each year were not tested for HBsAg to prevent perinatal transmission. More than 50% of HBsAg-positive persons did not receive the recommended HBV-directed monitoring tests during pregnancy and after delivery.

Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger - United States, 2023.

At its October 2022 meeting, the Advisory Committee on Immunization Practices* (ACIP) approved the Recommended Child and Adolescent Immunization Schedule for Ages 18 Years or Younger, United States, 2023. The 2023 child and adolescent immunization schedule, available on the CDC immunization schedule website (https://www.cdc.gov/vaccines/schedules), summarizes ACIP recommendations, including several changes from the 2022 immunization schedule† on the cover page, tables, notes, and appendix. Health care providers are advised to use the tables, notes, and appendix together to determine recommended vaccinations for patient populations. This immunization schedule is recommended by ACIP (https://www.cdc.gov/vaccines/acip) and approved by CDC (https://www.cdc.gov), the American Academy of Pediatrics (https://www.aap.org), the American Academy of Family Physicians (https://www.aafp.org), the American College of Obstetricians and Gynecologists (http://www.acog.org), the American College of Nurse-Midwives (https://www.midwife.org), the American Academy of Physician Associates (https://www.aapa.org), and the National Association of Pediatric Nurse Practitioners (https://www.napnap.org).