IZ Express

Issue 1764: July 3, 2024

Top Stories
 
Immunize.org Website and Clinical Resources
 
Vaccine Information Statements
 
Featured Resources
 
Notable Publications
 
Global News
 
Upcoming Events
 
Top Stories

Immunize.org summarizes ACIP’s June 26–28 meeting with new or updated recommendations for RSV, pneumococcal, influenza, COVID-19, and Hib-containing vaccines

The Advisory Committee on Immunization Practices (ACIP) met on June 26–28. During the 3-day meeting, ACIP voted on the following recommendations:

  • Routine, one-time RSV vaccination of all previously unvaccinated adults age 75 years and older, and vaccination of adults age 60–74 years with specific risk conditions only
  • Use of 21-valent pneumococcal conjugate vaccine (PCV21) as a product option for adults already recommended to receive PCV
  • Use of 2024–25 season influenza vaccines in all people age 6 months and older, and addition of high-dose and adjuvanted vaccine options for immunocompromised adults younger than age 65 years
  • Use of 2024–25 season COVID-19 vaccines in all people age 6 months and older
  • Addition of DTaP-IPV-Hib-HepB (Vaxelis, Merck/Sanofi, MSP) as a preferred product option for vaccination of American Indian and Alaska Native infants

The Committee received effectiveness and safety updates following the first season of maternal RSV vaccination and infant RSV immunization. Updates described progress toward new recommendations for vaccines against chikungunya and meningococcal disease and the status of dengue vaccine. Formation of a new ACIP workgroup for HPV vaccine was announced. Presentation slides are available online. Highlights of the meeting are provided below.

RSV vaccine in older adults (vote)
Disease burden
RSV is a frequent, often unrecognized, cause of respiratory illness in people of all ages. The likelihood of severe RSV lower respiratory tract disease (LRTD), hospitalization, and death increases with increasing age and among people with certain chronic health conditions. Between 2016–2020, RSV was associated with 90,000–140,000 hospitalizations and 6,000–10,000 deaths each year among U.S. adults age 65 years and older.

Background
In 2023, two protein-based RSV vaccines (Abrysvo, Pfizer; Arexvy, GSK) were licensed by FDA and recommended by ACIP for use as a single lifetime dose in adults age 60 years and older on the basis of shared clinical decision-making (SCDM), including a discussion of individual risks and benefits with a healthcare provider. The question of an increased risk for Guillain-Barré syndrome (GBS) after vaccination arose from clinical trial results; CDC and FDA began monitoring and evaluating GBS reports following RSV vaccination during implementation of ACIP’s recommendation. ACIP planned to revisit its 2023 recommendations after review of product safety and real-world effectiveness data following the initial season of use.

In May 2024, FDA licensed a third RSV vaccine, mResvia (Moderna), an mRNA vaccine given as a single dose for previously unvaccinated adults age 60 years and older. Clinical trials of this vaccine initially demonstrated approximately 80% effectiveness against LRTD with 2 or 3 symptoms, declining to just over 60% effectiveness after a median of 8.7 months and 50% effectiveness after 18 months. No safety issues were identified in clinical trials. On June 7, 2024, FDA also expanded its licensed indications for Arexvy to include vaccination of adults age 50–59 years at increased risk of severe consequences from RSV infection.

In addition to reviewing new real-world safety and effectiveness data for Abrysvo and Arexvy, ACIP evaluated the use of mResvia as a product option and considered whether to recommend a dose of Arexvy for high-risk adults age 50–59 years.

Safety and effectiveness
Evidence indicated reassuring, robust protection against RSV-associated hospitalization in older adults in the United States during the first season following recommended vaccination, consistent with the effectiveness against LRTD reported in clinical trials. Surveys and expert commentary indicated challenges to implementation of the SCDM-type recommendation in clinical practice, particularly the lack of time for discussions, lack of clarity about who would benefit from vaccination, inability to use standing orders or routine vaccination forecasting tools in electronic records systems, as well as some challenges with insurance coverage.

CDC presented safety information from its Vaccine Safety Datalink (VSD) monitoring system (August 2023–March 2024). This system detects “statistical signals” for prespecified outcomes. A statistical signal indicates a potential association with vaccination that warrants further evaluation. Patient chart review is underway to evaluate a statistical signal for immune thrombocytopenia (ITP) following Arexvy, in addition to a small number of GBS cases reported following vaccination with Arexvy and Abrysvo. No other statistical signals were observed. Results of additional analyses of GBS risk following RSV vaccination in other safety surveillance systems have been mixed. FDA is further analyzing the charts of reported cases and surveillance is ongoing. Estimates of the magnitude of the potential risk of GBS after vaccination were much smaller than the risk of death or hospitalization with RSV disease in all groups recommended by ACIP for vaccination at this meeting.

Revaccination
All RSV vaccines are currently licensed and recommended for one dose. Additional doses may be recommended in the future, but neither the appropriate interval between doses nor the benefit of additional doses are known. GSK presented information indicating revaccination with Arexvy 12 months after the first dose did not produce much clinical benefit. The antibody response to a dose given after 24 months was better but remained below the antibody level reached following the initial dose. Information on a 3-year interval will be presented at a future ACIP meeting.

Rationale for updating recommendations
The ACIP decision to routinely recommend RSV vaccination of all people age 75 years and older with a single lifetime dose was based upon their high rate of hospitalization with RSV and the new evidence of vaccine effectiveness in preventing hospitalization in this age group.

ACIP recommended routine RSV vaccination of adults age 60–74 years with specific risk factors for severe RSV disease and removed the SCDM option for those not at increased risk for three major reasons. First, otherwise healthy people age 60–74 years are at relatively low risk of RSV-associated hospitalization. Second, while the risk of GBS following RSV vaccination remains unclear, the small potential GBS risk may be similar to the small risk of death from RSV disease in otherwise healthy people this age. Finally, the timing and benefit of repeated vaccination is not yet known. For these reasons, the cost of vaccinating otherwise healthy people age 60–74 years was very high relative to the health benefit.

ACIP deferred making a recommendation on Arexvy for people age 50–59 years who are at increased risk of complications from RSV to a future meeting. Overall, the risk to younger adults with risk factors is lower than the risk to older adults with risk factors, although some conditions, such as chronic kidney disease, are clearly associated with significant risk. The RSV work group will return to the full committee for a vote as soon as it has sufficient information to propose a recommendation.

ACIP voted (11–0) to recommend a single dose of any RSV vaccine [Abrysvo, Arexvy, or mResvia] to:

  • Adults age 75 years and older
  • Adults age 60–74 years who are at increased risk* of severe disease

* Including those with lung disease, cardiovascular disease, moderate or severe immunocompromise, diabetes mellitus with end-organ damage, severe obesity (BMI of 40 kg/m2 or more), neurologic or neuromuscular conditions, advanced chronic kidney disease, liver disorders, hematologic disorders, other chronic medical conditions that a healthcare provider determines increase the risk of severe disease due to respiratory infection, or residing in a long term care facility. CDC will publish a complete list of risk factors in its clinical considerations for use of RSV vaccine in adults.

Important clinical considerations

  • Any licensed RSV vaccine (Abrysvo, Arexvy, or mResvia) may be used; ACIP expresses no preference
  • People age 60–74 years without an increased risk for severe disease are no longer recommended to receive RSV vaccine
  • A person who has already received RSV vaccine is not recommended to receive an additional dose, including those vaccinated during pregnancy
  • RSV vaccines may be coadministered with other vaccines
  • RSV vaccination is of most benefit if given in late summer or early fall, i.e., August to October for most of the United States

Pneumococcal 21-valent conjugate vaccine in adults (vote)
Background
Before the COVID-19 pandemic, there were over 100,000 noninvasive pneumococcal pneumonia hospitalizations, over 30,000 invasive pneumococcal disease (IPD) cases, and 3,000 IPD deaths each year in the United States. Risk of disease and severe outcomes is higher among older adults and adults with certain risk conditions. Disease is caused by a wide variety of pneumococcal serotypes. Vaccines are designed to provide protection against specific serotypes. The proportion of disease caused by specific pneumococcal serotypes varies by age.

Pneumococcal vaccination is recommended for the following adults:

  • Adults age 65 years and older
  • Adults age 19–64 years with certain underlying conditions or risk factors

Before the vote, adult pneumococcal vaccination options included 20-valent pneumococcal conjugate vaccine (PCV20) alone or a series of PCV15 followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23). For details of pneumococcal vaccine recommendations, see Immunize.org’s "Standing Orders for Administering Pneumococcal Vaccines (PCV15, PCV20, and PPSV23) to Adults." Two-thirds of adults age 65 and older have been vaccinated against pneumococcus, while just over 1 in 5 younger adults with a risk-based indication have been vaccinated.

PCV21 (Capvaxive, Merck)
On June 17, 2024, FDA licensed PCV21 for adults age 18 years and older. PCV21 was designed for use only in adults in countries with longstanding, high rates of PCV vaccination of children, including the United States. In such settings, many serotypes included in childhood PCV vaccines are now uncommon causes of disease in children or adults. U.S. children now routinely receive PCV15 or PCV20 in infancy. PCV21 includes 11 serotypes not included in PCV20 and excludes 10 serotypes included in PCV20. Serotypes in PCV21 cause approximately 85% of invasive pneumococcal disease in U.S. adults age 65 and older, while those in PCV20 cover 54%. ACIP discussed the fact that PCV21 does not include serotype 4 (included in PCV20), which is uncommon in the United States but has recently been identified in an increasing proportion of pneumococcal disease cases in certain regions and among certain groups, such as adults experiencing homelessness in the Western United States and Alaska Native adults.

During its deliberations, ACIP considered three groups for inclusion in its PCV21 recommendations. First, PCV21 was considered as an option for all adults age 19 years and older who are currently recommended to receive PCV. This was readily agreed. Second, due to its broad coverage and the challenges of vaccinating high-risk adults, ACIP considered recommending it for all adults beginning at age 50 or for all adults beginning at age 19 years. Robust discussion focused on the possibility of recommending the vaccine for adults age 50–64 years. Following unresolved questions related to estimates of economic costs and potential benefits, this policy question was returned to the work group for further deliberation. Members intend to resume consideration of an age-based recommendation beginning at age 50 at the ACIP meeting in October.

ACIP voted (11–0) to recommend PCV21 as an option for adults age 19 years and older who currently have a recommendation to receive a dose of PCV.

Influenza vaccine guidance for the 2024–25 season (2 votes)
Background
In March, FDA announced the selection of three influenza virus strains for the 2024–25 seasonal influenza vaccines. The A(H3N2) component is new; the other two components are unchanged from the previous season. The 2024–25 vaccine no longer contains an influenza B/Yamagata component because there have been no confirmed detections of influenza B/Yamagata viruses globally since March 2020.

Vaccine Safety
Vaccine safety surveillance systems detected no new safety concerns during the most recent influenza season.

Higher dose and adjuvanted influenza vaccines for solid organ transplant (SOT) recipients
Most (72%) of the 46,000 SOTs performed in 2023 were in people age 18–64 years. SOT recipients take immunosuppressive medications that diminish their response to vaccination and increase their risk of serious influenza illness. High-dose inactivated influenza vaccine (HD-IIV) and adjuvanted IIV (aIIV) are designed to trigger a stronger immune response to vaccination compared to standard-dose IIV or recombinant influenza vaccine (RIV). HD-IIV and aIIV are FDA-licensed only for people age 65 years and older, although a few studies have been conducted in small groups of SOT recipients. Based on these studies, the American Society for Transplantation suggests the use of HD-IIV or aIIV might be preferable in adult SOT recipients younger than age 65.

ACIP’s evaluation found no evidence of safety concerns for the use of these products in younger adult SOT recipients. Although available evidence does not directly demonstrate superior effectiveness of these products compared to standard-dose IIV or RIV options, it is plausible that HD-IIV or aIIV may provide additional benefit. An ACIP recommendation for off-label use of these products as an acceptable option for SOT recipients age 18–64 years would lead to insurance coverage for these products when administered to SOT recipients in this age group. With insufficient data to support a preference, HD-IIV and aIIV were added as acceptable options for younger adult SOT recipients, along with other IIV or RIV options.

ACIP voted (11–0) to reaffirm the recommendation for routine annual influenza vaccination of all persons age 6 months and older who do not have contraindications.

ACIP voted (11–0) to recommend high-dose inactivated (HD-IIV3) and adjuvanted inactivated (aIIV3) influenza vaccines as acceptable options for influenza vaccination of solid organ transplant recipients age 18 through 64 years who are on immunosuppressive medication regimens, without a preference over other age-appropriate IIV3s or RIV3.

COVID-19 vaccine recommendations for the 2024–25 season (vote)
Background
Overall uptake of the 2023–2024 Formula COVID-19 vaccines was low, with 14.4% of children and adolescents and 22.5% of U.S. adults age 18 years and older receiving the vaccine. Increasing age continues to be the most dominant risk factor for severe COVID-19 disease. Among adults, 67% of hospitalizations occurred in people age 65 years and older. Hospitalization rates were also higher among American Indian/Alaska Native (AI/AN) and black non-Hispanic populations, compared to the general population. Among children, hospitalization rates were highest among infants under age 6 months. Half of children admitted to the hospital with COVID-19 were otherwise healthy. Among hospitalized people, 5% of children and adolescents and 11% of adults had received a 2023–2024 Formula COVID-19 vaccine before hospital admission.

CDC provided updated estimates of COVID-19 vaccine effectiveness from several data systems. Because of frequent changes to the virus and variations in history of infections and vaccinations in the population, effectiveness estimates vary. From September 2023 through May 2024, during the first 2 months after vaccination, the estimated effectiveness of the 2023–2024 Formula COVID-19 vaccines for all immunocompetent patients tracked by these systems was roughly 50% against symptomatic infection, clinic visits, or hospitalization. Effectiveness began to wane after 2 months but appeared to be most durable for the prevention of critical illness.

CDC concluded that vaccination with a 2023–2024 Formula COVID-19 vaccine increased protection against illness, emergency visits, and hospitalizations, compared to people who did not receive the 2023–2024 Formula COVID-19 vaccine, and that the benefits were similar across age groups.

Vaccine safety
The Vaccine Safety Datalink (VSD) detected statistical signals (potential associations requiring further evaluation) for GBS and ischemic stroke related to 2023–24 season mRNA COVID-19 vaccines. Further studies are underway to evaluate the statistical signal for GBS following Pfizer COVID-19 vaccine among people age 65 years and older and the statistical signal for ischemic stroke after either mRNA vaccine. Conclusions about whether these statistical signals represent very small but real risks have not been made.

2024–2025 COVID-19 vaccine strain
On June 13, 2024, FDA announced that all 2024–25 COVID-19 vaccines will be updated to target a JN.1 lineage strain of the virus, the current dominant lineage. When feasible, the specific KP.2 strain of the JN.1 lineage will be used.

ACIP members expressed concern that serious COVID-19 disease still occurs in people of all ages and in healthy people with no specific risk factors. Evidence indicates that all age-eligible people can benefit meaningfully from vaccination in the coming season. The members urged healthcare providers to recommend or offer vaccination to all eligible patients.

ACIP voted (11–0) to recommend 2024–25 COVID-19 vaccines as authorized or approved by FDA in persons age 6 months and older.

DTaP-IPV-Hib-HepB (Vaxelis) use in American Indian/Alaska Native (AI/AN) infants (2 votes)

Background
For reasons not entirely understood, AI/AN children have historically had higher rates of Haemophilus influenzae type b (Hib) disease than the general population, with onset earlier in life. For this reason, AI/AN children are preferentially recommended to receive PedvaxHIB (Merck), which, until recently, was the only available Hib vaccine demonstrated to provide protective immunity after the first dose. As described in the February 2024 ACIP meeting, the combination vaccine, Vaxelis (Merck/Sanofi, MSP), which contains a smaller dose of the same type of Hib vaccine as PedvaxHIB, has been shown to provide protective immunity against Hib disease after the first dose.

Vaxelis consists of diphtheria and tetanus toxoids and acellular pertussis, inactivated poliovirus, Hib conjugate, and hepatitis B vaccines (DTaP-IPV-Hib-HepB). It is routinely recommended only for three doses, normally given at the 2-, 4-, and 6-month infant immunization visits. A different product must be used for the Hib booster at age 15 months.

Rationale for updating the recommendation
Adding Vaxelis as a preferential option for AI/AN infants gives healthcare providers options and reduces the number of injections to complete the immunization series for those who receive it.

ACIP voted (11–0) to recommend DTaP-IPV-Hib-HepB (Vaxelis) should be included with PRP-OMP (PedvaxHIB) in the preferential recommendation for American Indian and Alaska Native infants based on the Hemophilus influenzae type b (Hib) component.

Following the recommendation, ACIP voted unanimously to update the coverage of Vaxelis by the VFC program to include it as a preferred option for AI/AN children.


Influenza A(H5N1) (information)
CDC provided a brief update on the ongoing multistate outbreak of highly pathogenic avian influenza A(H5N1) virus in dairy cows and other animals in the United States. To date, the U.S. Department of Agriculture (USDA) has confirmed A(H5N1) virus infection in dairy herds on more than 100 farms in 12 states. Three mild human cases (all with conjunctivitis, one also with mild respiratory symptoms) have been confirmed among adults working at dairy farms and in contact with cows. No human-to-human transmission has been detected. Monitoring for additional cases is ongoing. The overall risk of A(H5N1) to the public remains low. The virus is present in raw milk of infected cows but is eliminated by routine pasteurization processes. CDC always recommends against the consumption of raw milk, which can transmit many pathogens.

CDC developed interim recommendations for preventing exposures to the virus. The agency also recently released updated guidance for fair exhibitors and organizers to help prevent influenza. Updated information is on CDC’s H5N1 Bird Flu web page.

Chikungunya vaccine (information)
In February 2024, ACIP voted to recommend the live attenuated virus chikungunya vaccine (Ixchiq, Valneva) for use in adult travelers to chikungunya-endemic areas and at-risk laboratory workers. A second chikungunya vaccine (containing a non-live, virus-like particle) for individuals age 12 years and older is currently under consideration by FDA and may be licensed in 2025.

Chikungunya is a painful disease transmitted by mosquitoes and is typically found in tropical and sub-tropical regions. ACIP received an update on chikungunya epidemiology in Puerto Rico and the U.S Virgin Islands, where approximately 30% of the population was infected during a large outbreak in 2014. Other U.S. territories, freely associated states, and Florida and Texas experienced cases in 2014 to a lesser degree. There has been no evidence of confirmed transmission in these areas since 2017. Timing of future outbreaks is unknown. ACIP will consider vaccine recommendations for residents of U.S. territories and states at risk, with the goal of minimizing the size and duration of future outbreaks.

Dengue vaccine (information)
In 2021, ACIP recommended vaccination with a 4-dose series of Dengvaxia (Sanofi) for individuals age 9–16 years who have evidence of previous dengue infection and live in areas where dengue is endemic, including American Samoa, Puerto Rico, U.S. Virgin Islands, the Federated States of Micronesia, the Republic of Marshall Islands, and the Republic of Palau.

Use of Dengvaxia was severely limited by the requirement for prevaccination testing, a complex billing process, limited public education, and the COVID-19 pandemic. Since September 2022, CDC reported that 32 people in Puerto Rico have been fully vaccinated as recommended.

Due to low demand, Sanofi discontinued manufacturing Dengvaxia. Currently available vaccine will expire in August 2026. Other dengue vaccines are in development, but none are currently being evaluated by the FDA. No dengue vaccines will be available in the United States after the discontinuation of Dengvaxia. Of note, dengue cases in the Americas have increased sharply in 2024, and Puerto Rico declared a dengue public health emergency in March.

Meningococcal vaccine (information)
FDA is evaluating GSK’s pentavalant meningococcal vaccine (MenABCWY), which contains the vaccines in the Bexsero brand of MenB and Menveo brand of MenACWY. ACIP reviewed preliminary information from GSK phase 3 trials. At upcoming meetings, the committee will consider options for use of the vaccine, along with the currently licensed and recommended Pfizer brand of MenABCWY vaccine that contains the vaccine in the Trumenba brand of MenB.

ACIP reviewed meningococcal disease epidemiology data, noting that, in 2023, the U.S. incidence of this rare disease increased from recent historic lows. The rise to 443 reported cases was due to an increase in serogroup Y disease, primarily among Black males age 30–60 years. Ciprofloxacin-resistant meningococcal infections have been increasing in the United States and globally, causing some jurisdictions to make changes in disease prophylaxis and treatment protocols.

RSV vaccine – pediatric/maternal (information)
In 2023, ACIP recommended two options to protect infants and young children from serious RSV disease: maternal RSV vaccination (Abrysvo, Pfizer) between 32 and 36 6/7 weeks’ gestation or administration of the preventive antibody, nirsevimab (Beyfortus, Sanofi), to infants younger than age 8 months. Children age 8–19 months at increased risk of severe RSV disease and entering their second RSV season are recommended to receive one dose of nirsevimab. CDC presented information on the implementation of these new recommendations.

Despite the challenges of implementation during the first season, including initial supply, distribution, and insurance coverage issues, 51.2% of eligible infants received protection from either nirsevimab or maternal vaccination last season. Among eligible pregnant people, 17.8% received maternal vaccination during the recommended time frame.

Abrysvo is recommended for one lifetime dose. ACIP currently recommends that a person who received one dose of Abrysvo should not be given Abrysvo during subsequent pregnancies; instead, infants born after subsequent pregnancies should receive nirsevimab after delivery.

Nirsevimab supplies are expected to be greatly increased during the 2024–25 season, with broad availability by October 1. CDC has developed a From Me, To You campaign to promote RSV and other vaccines during appropriate stages of pregnancy.

Formation of HPV vaccine work group (information)
ACIP announced the formation of a new HPV vaccine work group to reevaluate the number of doses recommended in the HPV vaccine series, the age range for routine HPV vaccination, and improved clinical guidance for vaccination of people age 27–45 years.

Next steps
The next scheduled ACIP meeting will be held on October 23–24, although additional emergency meetings may be announced prior to that time. Information about past and future ACIP meetings may be found on the ACIP website.

Related Links


CDC’s Health Alert Network (HAN) Health Advisory: Increased Risk of Dengue Virus Infections in the United States

On June 25, CDC issued a Health Alert Network (HAN) Health Advisory: Increased Risk of Dengue Virus Infections in the United States. A dengue vaccine (Dengvaxia, Sanofi) is licensed and recommended for children and adolescents age 9 through 16 years who were previously infected with dengue and who reside in Puerto Rico or another U.S. territory where dengue is endemic. Due to very low uptake, the manufacturer stopped production of Dengvaxia, although vaccine remains available until the last doses expire in late 2025. Dengue vaccination is not recommended for travelers to areas where dengue transmission is occurring. Portions of the summary of the HAN appear below.

Global incidence of dengue in 2024 has been the highest on record for this calendar year; many countries are reporting higher-than-usual dengue case numbers. In 2024, countries in the Americas have reported a record-breaking number of dengue cases, exceeding the highest number ever recorded in a single year. From January 1 – June 24, 2024, countries in the Americas reported more than 9.7 million dengue cases, twice as many as in all of 2023 (4.6 million cases). In the United States, Puerto Rico has declared a public health emergency (1,498 cases) and a higher-than-expected number of dengue cases have been identified among U.S. travelers (745 cases) from January 1 – June 24, 2024. In the setting of increased global and domestic incidence of dengue, healthcare providers should take steps including:

  1. Have increased suspicion of dengue among people with fever who have been in areas with frequent or continuous dengue transmission within 14 days before illness onset,
  2. Order appropriate diagnostic tests for acute DENV [dengue virus] infection: reverse transcription polymerase chain reaction [RT-PCR] and IgM antibody tests, or non-structural protein 1 [NS1] antigen tests and IgM antibody tests,
  3. Ensure timely reporting of dengue cases to public health authorities, and
  4. Promote mosquito bite prevention measures among people living in or visiting areas with frequent or continuous dengue transmission.

Access the complete CDC HAN Health Advisory.

Related Link


Immunize.org updates its patient handout, “You're 16 ... We Recommend These Vaccines for You!”

Immunize.org and the Society for Adolescent Health and Medicine (SAHM) recently updated their patient handout, You're 16 ... We Recommend These Vaccines for You! The handout now includes COVID-19 as a routinely recommended vaccine and a footnote was added to indicate that RSV vaccine may be recommended during pregnancy. Vaccines normally administered to preteens (but which may be needed by teens who are not up to date) are now grouped in a separate table.



Related Link


What is the minimum interval when repeating an expired live vaccine dose? Watch the 1-minute answer, part of the Ask the Experts Video Series on YouTube.

This week, our featured episode from the Ask the Experts Video Series reminds viewers of the minimum interval when repeating a live virus vaccine dose improperly administered to a patient after its expiration date.

The 1-minute video is available on our YouTube channel, along with our full collection of quick video answers to popular Ask the Experts questions.

Like, follow, and share Immunize.org’s social media accounts and encourage colleagues and others interested in vaccination to do likewise.


Vaccines in the news

These recent articles convey the potential risks of vaccine-preventable diseases and the importance of vaccination.


Immunize.org Website and Clinical Resources

Watch and share the new 3-minute video introduction to Immunize.org and its resources

Immunize.org is delighted to share a new, 3-minute online video introducing our organization and the resources available on our website. The video is available now on our YouTube channel as the first in a new orientation series of quick 3-minute videos. These videos help new and experienced users become more familiar with our new website and get the most out of all the resources we offer. Each new orientation video will be featured in IZ Express as it is released. Horizontal versions of these videos, like this one, will orient viewers to the desktop format of the website. Later, vertical versions of the videos will feature the mobile format of the site.



Please share this video with your colleagues, trainees, and anyone else who should know more about Immunize.org and how we can support effective immunization practices.


Vaccine Information Statements

Recap: Immunize.org posts revised versions of four Chinese translations of VISs for varicella-containing vaccines

Immunize.org removed parenthetical Chinese characters in the document title of varicella-containing vaccine VISs. These parenthetical characters refer broadly to pox viruses and do not refer exclusively to “chickenpox.” To avoid any confusion, these characters were removed from the titles. The English-language VISs are dated August 6, 2021.

Varicella (Chickenpox) Vaccine VIS (English language)

MMRV (Measles, Mumps, Rubella, Varicella) Vaccine VIS (English language)

To ensure you use the current translations, click on “Vaccines & VISs” at Immunize.org, click on “VISs,” and then select a specific vaccine. Scrolling down the resulting page, you will see the current English version, a list of current translations (i.e., corresponding to the current English VIS), and then, if applicable, a list of any out-of-date (yet best available) translations. Additional tips on using VISs appear at the bottom of the page.

Related Links


Featured Resources

CHOP Vaccine Education Center shares new resources, including "Pneumococcus and Adults” and videos addressing H5N1 influenza, COVID-19, and dengue vaccines

Children's Hospital of Philadelphia's (CHOP) Vaccine Education Center (VEC) developed a 1-page summary, Pneumococcus and Adults, to share information about the disease and vaccines to prevent it. Readers will learn about risk factors and disease complications.



VEC offers many infographics (in PNG and PDF formats) at its Vaccine- and Disease-Related Infographics main page. Each provides a brief overview related to a disease, vaccine, or related topic.

CHOP's VEC also released three new videos:



Related Links


Notable Publications

"Hepatitis B-CpG Vaccine Series for Healthcare Workers Who Are Hepatitis B Vaccine Nonresponders" published in Clinical Infectious Diseases

In its June 17 issue, Clinical Infectious Diseases published Hepatitis B-CpG Vaccine Series for Healthcare Workers Who Are Hepatitis B Vaccine Nonresponders. Healthcare workers who do not show serologic evidence of protection after two series of hepatitis B vaccinations meet the definition of HepB vaccine “nonresponders.” ACIP currently recommends no additional doses of HepB vaccine for nonresponders because they are considered unlikely to respond to repeated vaccine doses. Nonresponders require postexposure hepatitis B immune globulin if exposed to hepatitis B virus.

This study showed that 91% of healthcare workers who were nonresponders after receiving at least 5 doses of a standard aluminum-adjuvanted HepB vaccine did have a protective antibody response to HepB after vaccination with a 2-dose series of the CpG-adjuvanted Heplisav-B (Dynavax). The abstract with the authors’ interpretation appears below.

This prospective study enrolled healthcare workers (HCW) who were nonresponders following at least 5 doses of aluminum-adjuvanted hepatitis B vaccine received the 2-dose Heplisav-B (HepB-CpG) series. After two doses of HepB-CpG, 43/47 (91%) participants, and with 1 dose 41/49 (84%) responded. HepB-CpGcould be the preferred vaccine in HCW nonresponders.

Related Link


Global News

"Persistent Transmission of Circulating Vaccine-Derived Poliovirus—Somalia, January 2017–March 2024" published in MMWR

CDC published Persistent Transmission of Circulating Vaccine-Derived Poliovirus—Somalia, January 2017–March 2024 on June 27 in MMWR. A portion of the summary appears below.

Circulating vaccine-derived polioviruses (cVDPVs), associated with oral polio vaccines, can cause paralysis among persons in areas with low population immunity to polioviruses. In Somalia, cVDPV type 2 (cVDPV2) transmission has been ongoing since 2017, highlighting considerable challenges in controlling transmission. . . .

Since the 2016 global withdrawal of type 2 oral poliovirus vaccine, cVDPV2 has continued to circulate in Somalia, with 39 cases documented across multiple regions during 2017–2024. Despite extensive immunization activities, children in large portions of the country remain inaccessible, particularly in the South-Central region. . . .

Focusing on innovative strategies to vaccinate children in inaccessible areas, addressing operational challenges, and ensuring quality immunization campaigns in accessible regions are critical to interrupting cVDPV2 transmission in Somalia.


Access the MMWR article in HTML or PDF.



Related Link

  • CDC: MMWR main page providing access to the MMWR family of publications

Upcoming Events

Virtual: NFID hosts webinar, “Updates from June 2024 Advisory Committee on Immunization Practices (ACIP) Meeting,” on July 11 at 12:00 p.m. (ET); CE credit offered

NFID will host a webinar titled Updates from June 2024 Advisory Committee on Immunization Practices (ACIP) Meeting at 12:00 p.m. (ET) on July 11. NFID Medical Director Robert H. Hopkins, Jr., MD, and ACIP Deputy Executive Secretary Jessica R. MacNeil, MPH, will discuss the latest updates regarding U.S. vaccination recommendations.

CME and CNE credit are available. There is no fee to participate in this activity, but preregistration is required.

Register for the webinar.



NFID hosts monthly webinars to increase awareness of the importance of infectious disease prevention and treatment. CME, CNE, and CPE credits are available for select recordings. View all archived NFID webinars.


For more upcoming events, visit our Calendar of Events.

About IZ Express

IZ Express is supported in part by Grant No. 1NH23IP922654 from CDC’s National Center for Immunization and Respiratory Diseases. Its contents are solely the responsibility of Immunize.org and do not necessarily represent the official views of CDC.

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Editorial Information

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    Kelly L. Moore, MD, MPH
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    John D. Grabenstein, RPh, PhD
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