Varicella surveillance in public elementary schools--Multnomah County, Oregon, 2002-2004

Varicella vaccination of school-aged children reduces the number of varicella cases and lost days of school. In 1996, the Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination of all children aged 12-18 months, catch-up vaccination of all susceptible children before age 13 years, and vaccination of susceptible persons who have close contact with persons at high risk for serious complications and susceptible persons at high risk for exposure. In 1999, ACIP updated these recommendations to include vaccination requirements for child care and school entry. Since 2000, in accordance with ACIP recommendations, varicella vaccination requirements have been phased in for Oregon children who have not had varicella before starting out-of-home child care, kindergarten, or seventh grade; elementary school children will be fully covered by school year (SY) 2006-07. To monitor changes in varicella incidence, Oregon Health Services (OHS) and Multnomah Education Service District (MESD) started routine, individual, case-based varicella surveillance in Multnomah County public elementary schools (kindergarten through 5th grade) beginning SY 2002-03. This report describes the surveillance system, the incidence of varicella during SY 2002-03 and SY 2003-04, and the results of active surveillance for unidentified cases during SY 2002-03. The findings indicate that the number of varicella cases has decreased in Oregon and that establishing public elementary school-based varicella surveillance is feasible and useful.     

Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2011

This document provides updated guidance for the use of influenza vaccines in the United States for the 2011-12 influenza season. In 2010, the Advisory Committee on Immunization Practices (ACIP) first recommended annual influenza vaccination for all persons aged ≥6 months in the United States. Vaccination of all persons aged ≥6 months continues to be recommended. Information is presented in this report regarding vaccine strains for the 2011-12 influenza season, the vaccination schedule for children aged 6 months through 8 years, and considerations regarding vaccination of persons with egg allergy. Availability of a new Food and Drug Administration (FDA)-approved intradermally administered influenza vaccine formulation for adults aged 18 through 64 years is reported. For issues related to influenza vaccination that are not addressed in this update, refer to the 2010 ACIP statement on prevention and control of influenza with vaccines and associated updates.     

Pertussis--United States, 2001-2003

Pertussis is a highly contagious, vaccine-preventable bacterial illness characterized by paroxysmal cough, posttussive vomiting, and inspiratory whoop. Pertussis also can occur as a mild or moderate cough illness in persons who are partially immune. In the United States, most hospitalizations and nearly all deaths from pertussis are reported in infants aged <6 months, but substantial morbidity does occur in other age groups. Infant/childhood vaccination has contributed to a reduction of more than 90% in pertussis-related morbidity and mortality since the early 1940s in the United States. Estimates of childhood vaccination coverage with > or =3 doses of pertussis-containing vaccine have exceeded 90% since 1994; however, reported pertussis cases increased from a historic low of 1,010 in 1976 to 11,647 cases in 2003. A substantial increase in reported cases has occurred among adolescents, who become susceptible to pertussis approximately 6-10 years after childhood vaccination. Recently, booster vaccines for adolescents and adults combining pertussis antigens with tetanus and diphtheria toxoids (Tdap) were approved by the Food and Drug Administration (FDA). On June 30, 2005, the Advisory Committee on Immunization Practices (ACIP) recommended Tdap for all persons aged 11-18 years. This report summarizes national surveillance data on pertussis reported to CDC during 2001-2003 and focuses on pertussis reported among persons aged 10-19 years before implementation of national recommendations for adolescent pertussis vaccination.     

Update: recommendations from the Advisory Committee on Immunization Practices (ACIP) regarding administration of combination MMRV vaccine

On February 27, 2008, new information was presented to the Advisory Committee on Immunization Practices (ACIP) regarding the risk for febrile seizures among children aged 12-23 months after administration of the combination measles, mumps, rubella, and varicella (MMRV) vaccine (ProQuad, Merck & Co., Inc., Whitehouse Station, New Jersey). This report summarizes current knowledge regarding the risk for febrile seizures after MMRV vaccination and presents updated ACIP recommendations that were issued after presentation of the new information. These updated recommendations remove ACIP's previous preference for administering combination MMRV vaccine over separate injections of equivalent component vaccines (i.e., measles, mumps, and rubella [MMR] vaccine and varicella vaccine).     

Report from the Advisory Committee on Immunization Practices (ACIP): decision not to recommend routine vaccination of all children aged 2-10 years with quadrivalent meningococcal conjugate vaccine (MCV4)

At its February 2008 meeting, the Advisory Committee on Immunization Practices (ACIP) decided not to recommend routine vaccination of children aged 2-10 years against meningococcal disease unless the child is at increased risk for the disease. This report summarizes the deliberations of ACIP and the rationale for its decision and restates existing recommendations for meningococcal vaccination among children aged 2-10 years at increased risk for meningococcal disease. ACIP continues to recommend routine vaccination against meningococcal disease for all persons aged 11-18 years and those persons aged 2-55 years who are at increased risk for meningococcal disease.     

2006-2013年济南市历城区水痘疫情流行病学分析

摘要:目的　了解2006-2013年济南市历城区的水痘疫情的流行病学特征,为制定控制水痘流行的措施提供科学依据。方法　收集中国疾病预防控制信息系统中2006-2013年济南市历城区的水痘个案病例疫情信息,采用描述流行病学方法分析水痘的流行病学特征。结果　2006-2013年济南市历城区共报告水痘5 188例,8年平均发病率为62.61/10万,城乡结合部地区发病高于偏远农村地区,呈现春冬季两个发病高峰。病例中男性多于女性,以学生、幼托儿童、散居儿童为主,3～5岁年龄组发病率最高,其次为6～8岁年龄组,发病率分别为529.26/10万和450.79/10万。结论　儿童为水痘的高发人群,应重点加强托幼机构和学校的水痘防控工作;尽快制定并实施2针水痘疫苗的免疫策略,并将其纳入扩大免疫规划,切实提高水痘疫苗接种率和及时接种率,可有效降低水痘发病率,减轻水痘的疾病负担。     

Tetanus surveillance--United States, 1991-1994.

PROBLEM/CONDITION: Despite the widespread availability of a safe and effective vaccine against tetanus, 201 cases of the disease were reported during 1991-1994. Of patients with known illness outcome, the case-fatality rate was 25%. REPORTING PERIOD COVERED: 1991-1994. DESCRIPTION OF SYSTEM: Physician-diagnosed cases of tetanus are reported to local and state health departments, the latter of which reports these cases on a weekly basis to CDC's National Notifiable Disease Surveillance System. Since 1965, state health departments also have submitted supplemental clinical and epidemiologic information to CDC's National Immunization Program. RESULTS: During 1991-1994, 201 cases of tetanus were reported from 40 states, for an average annual incidence of 0.02 cases per 100,000 population. Of the 188 patients for whom age was known, 101 (54%) were aged > or = 60 years and 10 (5%) were aged < 20 years. No cases of neonatal tetanus were reported. Among adults, the risk for tetanus increased with age; the risk for persons aged > or = 80 years was more than 10 times greater than the risk for persons aged 20-29 years. All deaths occurred among persons aged > or = 30 years. The case-fatality rate (overall: 25%) increased with age, from 11% in persons aged 30-49 years to 54% in persons aged > or = 80 years. Only 12% of all patients were reported to have received a primary series of tetanus toxoid before onset of illness. For 77% of patients, tetanus occurred after an acute injury was sustained. Of patients who obtained medical care for their injury, only 43% received tetanus toxoid as part of wound prophylaxis. INTERPRETATION: The epidemiology of reported tetanus in the United States during 1991-1994 was similar to that during the 1980s. Tetanus continued to be a severe disease primarily of older adults who were unvaccinated or inadequately vaccinated. Most tetanus cases occurred after an acute injury was sustained, emphasizing the need for appropriate wound management. ACTIONS TAKEN: In addition to decennial booster doses of tetanus-diphtheria toxoid during adult life, the Advisory Committee on Immunization Practices (ACIP) recommends vaccination visits for adolescents at age 11-12 years and for adults at age 50 years to enable health-care providers to review vaccination histories and administer any needed vaccine. Full implementation of the ACIP recommendations should virtually eliminate the remaining tetanus burden in the United States.     

Supplemental recommendations on adverse events following smallpox vaccine in the pre-event vaccination program: recommendations of the Advisory Committee on Immunization Practices

The Advisory Committee on Immunization Practices (ACIP) has issued recommendations previously for use of smallpox vaccine and supplemental recommendations for use of smallpox vaccine in the pre-event civilian vaccination program. On March 28, 2003, CDC reported cases of cardiac adverse events among persons vaccinated recently with smallpox vaccine. In response to these reports, ACIP held an emergency meeting on March 28 to make recommendations to CDC about medical screening of potential vaccinees and follow-up of persons with cardiovascular risk factors after vaccination. These recommendations supplement those previously issued by ACIP.     

Hepatitis A vaccination coverage among children aged 24-35 months--United States, 2004-2005

After the licensure of hepatitis A vaccine in 1995 for children aged > or =24 months, the Advisory Committee on Immunization Practices (ACIP) incrementally expanded the proportion of children for whom it recommended the vaccine. In 1996, ACIP recommended vaccinating children in communities that had high rates of hepatitis A virus (HAV) infection, including American Indian/Alaska Native (AI/AN) communities and selected Hispanic and religious communities. In 1999, ACIP extended the recommendation to include routine vaccination for all children living in states, counties, and communities with incidence rates twice the 1987-1997 national average of 10 cases per 100,000 population (i.e., > or =20 cases per 100,000 population); ACIP also recommended considering vaccination for children living in states, counties, and communities with incidence rates exceeding the 1987-1997 national average (i.e., >10 to <20 cases per 100,000 population). National estimates of hepatitis A vaccination coverage were first made available through the 2003 National Immunization Survey (NIS), which indicated an overall national 1-dose coverage level of 16.0% (range: 6.4%-72.7%) among children aged 24-35 months. The estimates in this report update those findings by including 2 additional years of data (2004 and 2005). National 1-dose vaccination-coverage levels among children aged 24-35 months increased from 17.6% in 2004 to 21.3% in 2005. Coverage in states where vaccination was recommended (overall in 2005: 56.5%; range: 12.9%-71.0%) was below those for other recommended childhood vaccinations, such as varicella (87.5% in 2004). Despite low hepatitis A vaccination-coverage levels compared with other recommended childhood vaccinations, incidence of acute HAV infections have declined to the lowest level ever recorded. The 2005 licensure of the hepatitis A vaccine for use in younger children (aged > or =12 months) and the 2006 ACIP guideline for routine hepatitis A vaccination of all children aged > or =12 months should result in improved vaccination coverage and further reductions in disease incidence.     

Influenza vaccination in pregnancy: practices among obstetrician-gynecologists--United States, 2003-04 influenza season

Women infected with influenza virus during pregnancy are at increased risk for serious complications and hospitalization. During 1997-2003, the Advisory Committee on Immunization Practices (ACIP) included healthy pregnant women who would be in their second or third trimester of pregnancy during the influenza season among those persons at high risk for whom influenza vaccination was indicated. Also included were women at any stage of pregnancy with certain chronic medical conditions, such as asthma, diabetes mellitus, or heart disease. ACIP emphasized that the influenza vaccine was safe for breastfeeding mothers and their infants and that household contacts of children aged <2 years also should be vaccinated. However, despite these recommendations, only 13% of pregnant women received influenza vaccination in 2003. To assess understanding of the ACIP recommendations among obstetrician-gynecologists (OB/GYNs), the American College of Obstetricians and Gynecologists (ACOG), with support from CDC, surveyed a national sample of OB/GYNs in May 2004. This report describes the results of that survey, which indicated that 52% of OB/GYNs surveyed would recommend influenza vaccination for a healthy woman in the first trimester of pregnancy, 95% would recommend the vaccine for a healthy pregnant woman beyond the first trimester, and 63% would recommend vaccination for a woman with a medical condition in the first trimester. However, of the physicians who would recommend vaccination, 36%-38% reported that influenza vaccination was not offered in their practices. Increased efforts are needed to improve vaccine availability and to educate OB/GYNs regarding the updated ACIP recommendations on the use of influenza vaccine in the first trimester for both healthy pregnant women and pregnant women at high risk.     

Increasing uptake of live attenuated influenza vaccine among children in the United States, 2008–2014

The Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccination for all persons in the United States aged ≥6 months. On June 25, 2014, ACIP preferentially recommended live attenuated influenza vaccine (LAIV) for healthy children aged 2–8 years [1]. Little is known about national LAIV uptake. To determine uptake of LAIV relative to inactivated influenza vaccine, we analyzed vaccination records from six immunization information system sentinel sites (approximately 10% of US population). LAIV usage increased over time in all sites. Among children 2–8 years of age vaccinated for influenza, exclusive LAIV usage in the collective sentinel site area increased from 20.1% (2008–09 season) to 38.0% (2013–14). During 2013–14, at least half of vaccinated children received LAIV in Minnesota (50.0%) and North Dakota (55.5%). Increasing LAIV usage suggests formulation acceptability, and this preexisting trend offers a favorable context for implementation of ACIP's preferential recommendation.     

2013—2017年盐城市盐都区水痘流行特征和疫苗接种

目的 分析盐都区2013—2017年水痘发病特征和流行趋势,为制定防控措施提供科学依据。方法 采用描述流行病学方法对盐都区2013—2017年水痘发病资料和水痘疫苗接种资料进行分析。结果 2013—2017 年盐都区共报告水痘2 169例,男性1 196例,女性973例,男女性别比为1.23∶1,高发病年龄组为5岁及以上、10岁以下儿童(43.7/10万);年平均报告发病率为 60.7 /10万,年报告发病率呈逐年上升趋势;发病集中在5—6月和11月至次年1月,2月和8月较少;市区及城郊乡镇的年均发病率高于农村地区;发生5起聚集性疫情,均在学校、托幼机构,82 例病例中8例水痘突破病例;盐都区全人群水痘疫苗年均接种率1.15%,水痘疫苗接种率2014年最高(1.74%),2017年最低(0.34%)。结论 2013—2017年盐都区水痘发病情况呈上升趋势,5岁及以上、10岁以下的学生为高发人群,发病有春夏季和冬季2个高峰,市区及城郊乡镇发病率高于农村地区,水痘疫苗接种率自2016年开始急剧下降。今后应重点落实城郊地区适龄儿童家长水痘疫苗的告知工作,加强学校水痘防控知识宣传,将水痘发病控制在较低水平。     

Recommendations for using smallpox vaccine in a pre-event vaccination program. Supplemental recommendations of the Advisory Committee on Immunization Practices (ACIP) and the Healthcare Infection Control Practices Advisory Committee (HICPAC).

This report supplements the 2001 statement by the Advisory Committee on Immunization Practices (ACIP) (CDC. Vaccinia [smallpox] vaccine: recommendations of the Advisory Committee on Immunization Practices [ACIP], 2001. MMWR 2001;50[No. RR-10]:1-25). This supplemental report provides recommendations for using smallpox vaccine in the pre-event vaccination program in the United States. To facilitate preparedness and response, smallpox vaccination is recommended for persons designated by public health authorities to conduct investigation and follow-up of initial smallpox cases that might necessitate direct patient contact. ACIP recommends that each state and territory establish and maintain > or = 1 smallpox response team. ACIP and the Healthcare Infection Control Practices Advisory Committee (HICPAC) recommend that each acute-care hospital identify health-care workers who can be vaccinated and trained to provide direct medical care for the first smallpox patients requiring hospital admission and to evaluate and manage patients who are suspected as having smallpox. When feasible, the first-stage vaccination program should include previously vaccinated health-care personnel to decrease the potential for adverse events. Additionally persons administering smallpox vaccine in this pre-event vaccination program should be vaccinated. Smallpox vaccine is administered by using the multiple-puncture technique with a bifurcated needle, packaged with the vaccine and diluent. According to the product labeling, 2-3 punctures are recommended for primary vaccination and 15 punctures for revaccination. A trace of blood should appear at the vaccination site after 15-20 seconds; if no trace of blood is visible, an additional 3 insertions should be made by using the same bifurcated needle without reinserting the needle into the vaccine vial. If no evidence of vaccine take is apparent after 7 days, the person can be vaccinated again. Optimal infection-control practices and appropriate site care should prevent transmission of vaccinia virus from vaccinated health-care workers to patients. Health-care personnel providing direct patient care should keep their vaccination sites covered with gauze in combination with a semipermeable membrane dressing to absorb exudates and to provide a barrier for containment of vaccinia virus to minimize the risk of transmission; the dressing should also be covered by a layer of clothing. Dressings used to cover the site should be changed frequently to prevent accumulation of exudates and consequent maceration. The most critical measure in preventing contact transmission is consistent hand hygiene. Hospitals should designate staff to assess dressings for all vaccinated health-care workers. When feasible, staff responsible for dressing changes for smallpox health-care teams should be vaccinated, all persons handling dressings should observe contact precautions. Administrative leave is not required routinely for newly vaccinated health-care personnel unless they are physically unable to work as a result of systemic signs and symptoms of illness; have extensive skin lesions that cannot be adequately covered or if they are unable to adhere to the recommended infection-control precautions. Persons outside the patient-care setting can keep their vaccination sites covered with a porous dressing hand hygiene remains key to preventing inadvertent inoculation. FDA has recommended that recipients of smallpox vaccine be deferred from donating blood for 21 days or until the scab has separated. Contacts of vaccinees, who have inadvertently contracted vaccinia, also should be deferred from donating blood for 14 days after complete resolution of their complication. In the pre-event vaccination program, smallpox vaccination is contraindicated for persons with a history or presence of eczema or atopic dermatitis; who have other acute, chronic, or exfoliative skin conditions; who have conditions associated with immunosuppression; are aged < 1 year; who have a serious allergy to any component of the vaccine; or who are pregnant or breastfeeding. ACIP does not recommend smallpox vaccination for children and adolescents aged < 18 years during the pre-event vaccination program. Pre-event vaccination also is contraindicated among persons with household contacts who have a history or presence of eczema or atopic dermatitis; who have other acute, chronic, or exfoliative skin conditions; who have conditions associated with immunosuppression; or who are pregnant. For purposes of screening for contraindications for pre-event vaccination, household contacts include persons with prolonged intimate contact (e.g., sexual contacts) with the potential vaccinee and others who might have direct contact with the vaccination site. Persons with inflammatory eye disease might be at increased risk for inadvertent inoculation as a result of touching or rubbing the eye. Therefore, deferring vaccination is prudent for persons with inflammatory eye diseases requiring steroid treatment until the condition resolves and the course of therapy is complete. Eczema vaccinatum, a serious form of disseminated vaccinia infection, can occur among persons with atopic dermatitis and other dermatologic conditions. Potential vaccinees should be queried regarding the diagnosis of atopic dermatitis or eczema in themselves or any member of their household, or regarding the presence of chronic or recurrent rashes consistent with these diagnoses. Persons reporting such a rash in themselves or household members should not be vaccinated, unless a health-care provider determines that the rash is not eczema or atopic dermatitis. Before vaccination, women of childbearing age should be asked if they are pregnant or intend to become pregnant during the next 4 weeks; women who respond positively should not be vaccinated. Any woman who thinks she might be pregnant or who wants additional assurance that she is not pregnant should perform a urine pregnancy test on the day scheduled for vaccination. If a pregnant woman is inadvertently vaccinated or if she becomes pregnant within 4 weeks after smallpox vaccination, she should be counseled regarding concerns for the fetus. Vaccination during pregnancy should not ordinarily be a reason to terminate pregnancy. CDC has established a pregnancy registry to prospectively follow the outcome of such pregnancies and facilitate the investigation of any adverse pregnancy outcome among pregnant women who were inadvertently vaccinated. For enrollment in the registry, contact CDC at 404-639-8253. Smallpox vaccine should not be administered to persons with human immunodeficiency virus infection (HIV) or acquired immunodeficiency syndrome (AIDS) as part of a pre-event program because of their increased risk for progressive vaccinia. HIV testing is recommended for persons who have any history of a risk factor for HIV infection or for anyone who is concerned that he or she might have HIV infection. HIV testing should be available in a confidential or anonymous setting, in accordance with local laws and regulations, with results communicated to the potential vaccinee before the planned date of vaccination. Smallpox vaccine can be administered simultaneously with any inactivated vaccine. With the exception of varicella vaccine, smallpox vaccine can be administered simultaneously with other live-virus vaccines. To avoid confusion in ascertaining which vaccine might have caused postvaccination skin lesions or other adverse events, varicella vaccine and smallpox vaccine should be administered >4 weeks apart. Health-care workers scheduled to receive an annual purified protein derivative (PPD) skin test for tuberculosis screening should not receive the skin test until >1 month after smallpox vaccination. Persons with progressive vaccinia, eczema vaccinatum, and severe generalized vaccinia or inadvertent inoculation might benefit from therapy with VIG or cidofovir, although the latter has not been approved by FDA for this indication. Suspected cases of these illnesses or other severe adverse events after smallpox vaccination should be reported immediately to state health departments. VIG and cidofovir are available from CDC under Investigational New Drug protocols. Clinically severe adverse events after smallpox vaccination should be reported to the Vaccine Adverse Event Reporting System. Reports can be made online at https://secure.vaers.org/VaersDataEntryintro.htm, or by postage-paid form, which is available by calling 800-822-7967 (toll-free). ACIP will review these recommendations periodically as new information becomes available related to smallpox disease, smallpox vaccines, the risk of smallpox attack, smallpox vaccine adverse events, and the experience gained as recent recommendations are implemented. Revised recommendations will be developed as needed.     

Updated recommendations for use of meningococcal conjugate vaccines --- Advisory Committee on Immunization Practices (ACIP), 2010

On October 27, 2010, the Advisory Committee on Immunization Practices (ACIP) approved updated recommendations for the use of quadrivalent (serogroups A, C, Y, and W-135) meningococcal conjugate vaccines (Menveo, Novartis; and Menactra, Sanofi Pasteur) in adolescents and persons at high risk for meningococcal disease. These recommendations supplement the previous ACIP recommendations for meningococcal vaccination . The Meningococcal Vaccines Work Group of ACIP reviewed available data on immunogenicity in high-risk groups, bactericidal antibody persistence after immunization, current epidemiology, vaccine effectiveness (VE), and cost-effectiveness of different strategies for vaccination of adolescents. The Work Group then presented policy options for consideration by the full ACIP. This report summarizes two new recommendations approved by ACIP: 1) routine vaccination of adolescents, preferably at age 11 or 12 years, with a booster dose at age 16 years and 2) a 2-dose primary series administered 2 months apart for persons aged 2 through 54 years with persistent complement component deficiency (e.g., C5-C9, properidin, factor H, or factor D) and functional or anatomic asplenia, and for adolescents with human immunodeficiency virus (HIV) infection. CDC guidance for vaccine providers regarding these updated recommendations also is included.     

Understanding physician agreement with varicella immunization guidelines

BACKGROUND: Although varicella vaccine was licensed in 1995, immunization rates are only moderate. This study identifies factors associated with physician self-reported likelihood of recommending varicella vaccination to patients. METHODS: Two hundred eighty-one Minnesota and Pennsylvania primary care physicians who participated in surveys on barriers to vaccination in 1990-1991 and 1993 were surveyed in 1999, assessing physicians' beliefs about varicella disease and vaccine and their self-reported likelihood of recommending varicella vaccine to three age groups of children. RESULTS: Most (79, 80, and 83%) were likely to recommend varicella vaccine for 12- to 18-month old, 4- to 6-year-old, and 11- to 12-year old children, respectively, and most (78%) agreed with national recommendations to vaccinate. If physicians believed that the vaccine would fail, they were less likely to recommend varicella vaccination for 12- to 18-month-old (70% vs 85%, P = 0.001) and 4- to 6-year-old (83% vs 85%, P = 0.001) children, than if they believed in its efficacy. Pediatricians were more likely to recommend varicella vaccine than were family physicians and general practitioners (P < 0.01). CONCLUSIONS: Physicians, especially pediatricians, report that they recommend varicella vaccination when they agree with national recommendations, believe in the efficacy of the vaccine, and perceive that parents want the vaccine for their children.     

Influenza vaccination coverage among children aged 6-23 months--United States, 2005-06 influenza season

Children aged <2 years are at increased risk for influenza-related hospitalizations, and those aged <5 years have more influenza-related health-care visits than older children. In 2004, the Advisory Committee on Immunization Practices (ACIP) recommended annual influenza vaccination of children aged 6-23 months. Two doses, at least 4 weeks apart, were recommended to fully vaccinate children aged <9 years who were receiving influenza vaccination for the first time. To assess influenza vaccination coverage among children aged 6-23 months during the 2005-06 influenza season, data from the 2006 National Immunization Survey (NIS) were analyzed. This report describes the results of that analysis, which indicated that 31.9% of children in this age group received at least 1 dose of influenza vaccine and 20.6% were fully vaccinated according to ACIP recommendations; however, results varied substantially among states. The results underscore the need to continue to monitor influenza vaccination coverage among young children, develop systems to provide childhood influenza vaccination services more efficiently, and increase awareness among health-care providers and caregivers about the effectiveness of influenza vaccination among young children.     

Childhood influenza vaccination coverage--United States, 2004-05 influenza season

Children aged <2 years are at increased risk for influenza-related hospitalizations, and children aged 24-59 months are more likely than older children to visit a clinic, hospital, or emergency department with influenza-associated illness. In 2002, the Advisory Committee on Immunization Practices (ACIP) encouraged annual influenza vaccinations for children aged 6-23 months (and for household contacts of and out-of-home caregivers for children aged <2 years). For the 2004-05 influenza season, ACIP strengthened its encouragement to a full recommendation. For the upcoming 2006-07 influenza season, ACIP has further extended its recommendation to include all children aged 6-59 months (and their household contacts and out-of-home caregivers). Others recommended to receive influenza vaccination include children aged 6-18 years who have certain high-risk medical conditions, are on chronic aspirin therapy, or who are household contacts of persons at high risk for influenza complications. This report provides an assessment of influenza vaccination coverage among children aged 6-23 months during the 2004-05 influenza season. The findings demonstrate that vaccination coverage in that age group approximately doubled from the 2003-04 influenza season, with substantial variability among states and urban areas. However, the percentage of fully vaccinated children remained low, underscoring the need for increased measures to improve pediatric vaccination coverage and ongoing monitoring of coverage among young children and their close contacts.     

Tiered use of inactivated influenza vaccine in the event of a vaccine shortage

The United States has experienced disruptions in the manufacture or distribution of inactivated influenza vaccine during three of the last five influenza seasons. Delays in delivery of influenza vaccine or vaccine shortages remain possible, in part, because of inherent time constraints in manufacturing the vaccine, given the annual updating of influenza vaccine strains and uncertainties regarding vaccine supply (including licensure of new vaccine preparations). Although total vaccine supply for the 2005-06 influenza season is not yet known, the minimum anticipated supply is approximately 58-60 million doses of inactivated vaccine and 3 million doses of live, attenuated vaccine. This estimated supply is similar to that available during the 2004-05 season and would be adequate to satisfy historical demand for influenza vaccine among persons considered by the Advisory Committee on Immunization Practices (ACIP) to be at high risk for serious complications associated with influenza virus infection, health-care workers, and household contacts of children aged <6 months. These groups were prioritized for influenza vaccination in 2004-05. Additional doses of inactivated influenza vaccine might be available for the U.S. market in 2005-06, but this cannot yet be confirmed. Availability of additional vaccine would allow for expansion of the priority groups and, preferably, vaccination of all persons who desire it.     

Estimates of influenza vaccination target population sizes in Spain for the 2006-2007 season

This study sought to estimate influenza vaccination target population sizes in Spain for the 2006-2007 season, based firstly on current vaccine recommendations, and secondly, on the hypothetical assumption that Advisory Committee on Immunization Practices (ACIP) recommendations were to be implemented. We estimate that under present Spanish guidelines, 41% of the population should be vaccinated against influenza in the 2006-2007 season. Of those eligible for vaccination, 41% are aged >or=65 years, 16% are aged <65 years and suffer from a chronic condition, and 36% are healthy household contacts aged <65 years. If the ACIP recommendations were implemented in Spain, the target population size would increase to 26,761,506 persons (61%), and of those eligible for vaccination, 57% would fall within the age-based recommendations (ages 6-59 months or >or=50 years), 29% would come under the healthy household contacts category, and only 5% would qualify due to suffering from a medical condition. We thus conclude that approximately 18 million persons, 41% of the Spanish population, should receive influenza vaccination in the 2006-2007 season under present Spanish guidelines. With the estimated number of doses to be distributed during this season (10 million), compliance with current recommendations would amount to only 56% at best. Extending universal vaccination to the 50-64 age group should be considered as an option for improving influenza vaccination coverage, particularly among high-risk patients, because a greater proportion of persons would receive the recommended dose by becoming eligible for the more effective age-based strategies.     

Seasonal influenza vaccination coverage among children aged 6 months-18 years --- eight immunization information system sentinel sites, United States, 2009-10 influenza season

Annual influenza vaccination was first recommended for children aged 6-23 months and 2-4 years by the Advisory Committee on Immunization Practices (ACIP) in 2004 and 2006, respectively. In August 2008, ACIP expanded its seasonal influenza vaccination recommendations to also include all children aged 5-18 years no later than the 2009-10 season. To update previous estimates of seasonal influenza vaccination coverage among children aged 6 months-18 years, CDC analyzed data from the eight immunization information system (IIS) sentinel sites for the 2009-10 influenza season. Vaccination coverage with influenza A (H1N1) 2009 monovalent vaccine is not included in this report. Average (unweighted) vaccination coverage with ≥1 seasonal influenza vaccine doses was 26.3%, a 5.5 percentage point increase from the 2008-09 season (20.8%). Increases varied by age group, ranging from almost no increase among children aged 6-23 months (55.2% during the 2008-09 season to 55.7% during the 2009-10 season) to notable increases among children aged 2--4 years (from 33.0% to 38.4%), 5-12 years (19.0% to 27.1%), and 13-18 years (10.9% to 15.3%). Full vaccination coverage was low during the 2009-10 season, ranging from 34.7% among children aged 6-23 months to 15.3% among children aged 13-18 years. These findings highlight the need to identify varied strategies and venues for delivering influenza vaccine to different age groups of children to increase vaccination coverage.