Ask the Experts: All Questions

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Results (1355)

No. Tdap should be administered as soon as possible.

Last reviewed: March 31, 2022

You are interpreting the recommendations correctly, and age is an important factor in this issue. The recommendation for Hib vaccination for asplenia applies to persons of all ages. The recommendation for Hib vaccination for immunoglobulin deficiency applies only to children 12 through 59 months of age.

Last reviewed: July 31, 2022

No. It is the volume of the dose, not the antigen content, that is important. People 20 years and older should always receive a 1.0 mL dose of either Engerix-B or Recombivax HB when using those products. Likewise, people younger than 20 years should always receive a 0.5 mL dose of the pediatric formulation of either Engerix-B or Recombivax HB.

Last reviewed: July 21, 2023

No. The ACIP meningococcal serogroup B vaccine recommendations state that the same vaccine (either Bexsero by GSK or Trumenba by Pfizer) must be used for all doses in the MenB series, including booster doses. If the brand of a previous dose is unavailable or cannot be determined, restart the primary series with the available brand. The pentavalent MenABCWY product Penbraya (Pfizer) contains MenB-Fhbp (Trumenba) as its MenB component; therefore, Penbraya should only be used in series with Trumenba.

Last reviewed: March 24, 2024

CDC has established strict accuracy criteria for the laboratory tests considered acceptable proof of past DENV infection before vaccination of a child.

No test is perfectly accurate: wrong results lead to different types of risk. A false negative test result means a child who is at increased risk of severe dengue would not be protected by vaccination. A false positive test means a child who was not at high risk of severe dengue would be vaccinated, potentially increasing the child’s risk of severe dengue if the child experiences a subsequent DENV infection.

All dengue IgG tests for pre-vaccination screening must have a minimum specificity of at least 98% to minimize the chance of misclassifying a person who should have a true negative test result as positive. This high specificity minimizes the risk of vaccinating a person who should not be vaccinated.

Pre-vaccination screening tests must also have a sensitivity of at least 75% to accurately identify a high proportion of children and adolescents with past dengue virus infections who can benefit from vaccination.

Acceptable laboratory confirmation of previous dengue virus infection can be obtained by:

  • Evidence of prior acute dengue virus infection with
    • Positive dengue RT-PCR test result, or
    • Positive dengue NS1 antigen test result
  • OR, positive results on BOTH of the following anti-dengue virus IgG antibody tests in a two-step testing algorithm:
    • EUROIMMUN Anti-Dengue Virus NS1 Type 1-4 ELISA (IgG) and
    • CTK BIOTECH OnSite Dengue IgG Rapid Test

Visit www.cdc.gov/dengue/vaccine/hcp/testing.html. for additional information about laboratory testing requirements for vaccination with Dengvaxia. As additional tests are evaluated and approved as acceptable, information will be updated by CDC.

Vaccinators are encouraged to use the CDC prevaccination checklist to evaluate patient eligibility: www.cdc.gov/dengue/resources/DVBD_FS_Vaccination_Checklist-508.pdf.

Last reviewed: February 16, 2022

PPSV23 has only limited indications in children age 2 through 18 years who have not had PCV20 and are at high risk for serious pneumococcal infection due to the presence of a specific non-immunocompromising (non-IC) or immunocompromising (IC) medical condition.

If PCV20 is not offered, PPSV23 is recommended as an option to be administered to a child age 2 years or older at least 8 weeks following completion of PCV vaccination with PCV13 or PCV15. If a child has an immunocompromising condition and PPSV23 is used, a dose of PCV20, or a second dose of PPSV23, should be given 5 years later.

Immunize.org details all recommendations and pneumococcal vaccine options for children with high-risk conditions in its standing order template for pneumococcal vaccination of children and teens (www.immunize.org/wp-content/uploads/catg.d/p3086.pdf) and its shorter resource, Recommendations for Pneumococcal Vaccines Use in Children and Teens (www.immunize.org/wp-content/uploads/catg.d/p2016.pdf).

Last reviewed: November 13, 2024

Coverage levels for HPV vaccine are improving but are still inadequate. Results from CDC’s 2022 National Immunization Survey-Teen (NIS-Teen) indicate that for the first time since 2013, HPV vaccination initiation did not increase among adolescents age 13 through 17 years. HPV vaccination initiation actually fell among adolescents insured by Medicaid and remained lowest among the uninsured. The Vaccines for Children (VFC) program ensures access to HPV and other routine vaccines for adolescents who are uninsured or Medicaid-eligible at no cost. It is important that families are aware of this entitlement and the importance of HPV vaccination.

In 2022, 76% of adolescents had received at least 1 dose of HPV vaccine and 62.6% were up to date with HPV vaccination. A summary of the 2022 NIS-Teen survey and trends are available at www.cdc.gov/mmwr/volumes/72/wr/mm7234a3.htm.

Providers can improve uptake of this life-saving vaccine in several ways. First, studies show that missed opportunities are occurring. Some clinics address this by routinely starting the 2-dose vaccination series as early as possible, at age 9, giving them more chances to complete the series on time before age 13. A different strategy to improve uptake is by ‘bundling’ the recommendations for all adolescent vaccines at the first preteen visit. CDC recommends the following discussion starter: “Now that your child is 11, they need three vaccines to help protect against meningitis, HPV cancers, and whooping cough. We’ll give these shots during today’s visit. Do you have any questions about these vaccines?”

One of the main reasons parents give researchers for not vaccinating their adolescents is that the HPV vaccine was not recommended to them by their child’s healthcare provider. CDC urges healthcare providers to strongly and consistently recommend HPV vaccine, especially when patients are age 11 or 12 years. CDC’s “Talking to Parents about HPV Vaccine,” available at www.cdc.gov/hpv/media/pdfs/2024/07/talking_to_parents_HPV.pdf can help providers with these conversations.

For more detailed information about HPV vaccination strategies for providers, visit www.cdc.gov/hpv/hcp/boosting-vacc-rates.html and www.cdc.gov/vaccines/partners/routine-immunizations-lets-rise.html.

Last reviewed: July 26, 2024

Yes, influenza vaccines may be coadministered with other recommended vaccines.

The live attenuated nasal spray influenza vaccine (FluMist, LAIV) may be given on the same day as any other live or inactivated vaccines. However, if two live vaccines are not given on the same day, they should be separated by at least 4 weeks.

There are now several vaccines containing nonaluminum adjuvants recommended for adults (including Shingrix [zoster], Heplisav-B [HepB], Arexvy [RSV] and Fluad [aIIV, influenza]). Because of the limited data on the safety or reactogenicity of simultaneous administration of two or more vaccines containing nonaluminum adjuvants and the availability of nonadjuvanted influenza vaccine options, ACIP advises considering a nonadjuvanted influenza vaccine in situations in which influenza vaccine and another vaccine containing a nonaluminum adjuvant are due at the same visit. However, influenza vaccination should not be delayed if a specific vaccine is not available.

Last reviewed: August 11, 2024

The original COVID-19 vaccines all targeted the spike protein of the original SARS-CoV-2 virus. The 2024–2025 formulation vaccines target the spike proteins of more recently circulating strains, known as the Omicron KP.2 (mRNA vaccines) or JN.1 (protein vaccine) strains. The update is intended to boost production of antibodies that protect more effectively against disease caused by currently circulating Omicron subvariants.

The process of updating the strain without changing anything else is similar to the seasonal strain changes made for influenza vaccinations each year; FDA does not require manufacturers to repeat the large-scale clinical trials necessary for the original products before authorizing updated vaccines. Vaccine safety, side effects, and risk of allergic reactions are expected to be comparable to earlier formulations of vaccines of the same brand and dose. As with seasonal influenza vaccines, future COVID-19 vaccines can continue to be updated when needed, as the circulating viruses evolve.

Last reviewed: August 31, 2024

Yes. Doses of any meningococcal ACWY vaccine given before 10 years of age should not be counted as part of the adolescent MenACWY series. If a child received a dose of MenACWY before age 10 years, they should receive a dose of MenACWY at 11 or 12 years and a booster dose at age 16.

Last reviewed: November 15, 2024


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Last reviewed: August 11, 2024

Yes, coadministration of influenza and RSV vaccines at the same visit is acceptable. Evidence is limited and mixed concerning the effects of coadministration on antibody titers or on any increase in side effects (reactogenicity) experienced by the recipient following coadministration. CDC has provided the details of available information in its guidance on RSV vaccination of older adults: www.cdc.gov/vaccines/vpd/rsv/hcp/older-adults.html#administration-other-vaxs.

CDC advises that when deciding whether to coadminister other vaccines with an RSV vaccine, consider whether the patient is up to date with currently recommended vaccines, the feasibility of the patient returning for additional vaccine doses, their risk for acquiring vaccine-preventable disease, vaccine reactogenicity profiles, and patient preferences.

Last reviewed: August 11, 2024

Healthcare providers should vaccinate any person who failed to get vaccinated in the previous vaccination season and who wants to reduce their risk of getting influenza during their upcoming travel, particularly if they are at high risk for influenza-related complications. This includes people who are traveling to the tropics, traveling with organized tourist groups at any time of year, or traveling to the Southern Hemisphere during April–September.

Last reviewed: August 11, 2024

Yes. In its 2018 recommendations for the prevention of herpes zoster, ACIP states that Shingrix may be used in adults age 50 years or older irrespective of prior receipt of varicella vaccine or live zoster vaccine (Zostavax, Merck). Shingrix is also recommended for adults age 19 and older who are immunocompromised due to disease or treatment if they have a history of varicella illness or vaccination.

Last reviewed: May 16, 2023
Recommended dosages and schedules of hepatitis A vaccines
Vaccine Age group Dose Volume # Doses Schedule
Havrix
(GSK)		 1–18 years 720 El.U.* 0.5 ml 2 0, 6–12 mos.
19 years and older 1440 El.U.* 1.0 ml 2 0, 6–12 mos.
Vaqta
(Merck & Co.)		 1–18 years 25 U** 0.5 ml 2 0, 6–18 mos.
19 years and older 50 U** 1.0 ml 2 0, 6–18 mos.

*El.U. = Elisa Units **U = Units

 

Combination vaccine using hepatitis A and hepatitis B vaccines
Vaccine Age group Antigens used Volume # Doses Schedule
Twinrix
(GSK)		 18 years and older Havrix (720 El.U.)
combined with
Engerix-B (20 mcg)		 1.0 ml 3 0, 1, 6 mos.
4 0, 7, 21-30 days, 12 months**

** Accelerated schedule may be used for rapid protection prior to travel or for rapid protection of an unexposed but at-risk person who also would benefit from hepatitis B protection. Twinrix is not recommended for use as post-exposure prophylaxis.

Last reviewed: June 25, 2023

Yes. Rotavirus vaccine virus is shed during the first weeks after administration of rotavirus vaccine. Handwashing after diaper changing is always recommended.

Last reviewed: June 7, 2023

Yes. If different brands of Hib vaccine are given at 2 and 4 months of age then the child should receive a third primary dose of either vaccine at 6 months of age. A 2-dose primary schedule (that is, doses at age 2 and 4 months) is only appropriate when both doses are PedvaxHIB.

Last reviewed: July 31, 2022

ACIP does not address the use of this method for vaccination in its “Best Practices Guidelines for Immunization” (www.cdc.gov/vaccines/hcp/acip-recs/general-recs/administration.html). If you choose to use this method, you should still adhere to the ACIP’s recommendations regarding needle length and anatomical site.

Last reviewed: December 28, 2022

Explain to the parent that vaccination starting at 11 or 12 years will provide the best protection possible long before the start of any kind of sexual activity. It is standard practice to vaccinate people before they are exposed to an infection, as is the case with measles and the other recommended childhood vaccines. Similarly, we want to vaccinate children before they get exposed to HPV. Studies of HPV vaccine indicate that younger adolescents respond better to the vaccine than older adolescents and young adults. Healthy children vaccinated at this age will need only 2 doses of vaccine rather than 3 doses if vaccinated at an older age. Finally, numerous research studies have shown that getting the HPV vaccine does not make kids more likely to be sexually active or start having sex at a younger age.

Last reviewed: March 2, 2024

All immunocompetent people age 50 years or older-whether they have a history of chickenpox or shingles or not-should be given Shingrix unless they have a medical contraindication to vaccination. Among this population it is not necessary to ask about a history of chickenpox or to test for varicella antibody prior to or after giving the vaccine.

Among immunocompromised people age 19 years or older, evidence of a history of varicella illness or varicella vaccination (confirming the need for Shingrix as a result of a history of exposure to a live varicella virus, whether the wild or live-attenuated vaccine strain) IS recommended. Shingrix may be administered to an immunocompromised person who has had chickenpox or shingles or has previously been vaccinated with varicella vaccine or zoster vaccine live. See the Immunocompromised Adults section for additional information about partially-vaccinated immunocompromised adults with no history of chickenpox.

Last reviewed: March 9, 2022

Heplisav-B (Dynavax) was approved by the Food and Drug Administration (FDA) in November 2017 for people 18 years of age and older. Heplisav-B contains a novel adjuvant (CpG 1018) that binds to Toll-like receptor 9 to stimulate the immune response to HBsAg. It is provided in a single dose 0.5 mL vial and given as a 2-dose series with doses separated by 1 month (4 weeks).

Heplisav-B was approved based on clinical trials that compared seroprotection rates (SPR, defined as anti-HBs of 10 mIU or higher, and indicative of protection against hepatitis B infection) following 2 doses of Heplisav-B to rates following 3 doses of Engerix-B (GSK). Among people 18 through 70 years of age, SPRs were 90%–95% following 2 doses of Heplisav-B and 65%–81% following 3 doses of Engerix-B. Local reactions were most commonly reported (injection site pain, redness, and swelling) and were similar in frequency to those following Engerix-B.

The package insert for Heplisav-B is available here: www.fda.gov/media/108745/download.

Last reviewed: July 21, 2023

In the 2013 revision of its MMR vaccine recommendations ACIP includes laboratory confirmation of disease as evidence of immunity for measles, mumps, and rubella. ACIP removed physician diagnosis of disease as evidence of immunity for measles and mumps. Physician diagnosis of disease had not previously been accepted as evidence of immunity for rubella. With the decrease in measles and mumps cases over the last 30 years, the validity of physician-diagnosed disease has become questionable. In addition, documenting history from physician records is not a practical option for most adults. The 2013 MMR ACIP recommendations are available at www.cdc.gov/mmwr/pdf/rr/rr6204.pdf.

Last reviewed: June 19, 2023

Your solution will meet the spirit of the federal law, as long as you make sure to encourage the patient (or parent) to take home a paper copy of the VIS and to refer to it if needed (e.g., if they need to know what to do if there is an adverse event or how to contact VAERS).

Last reviewed: June 6, 2023

No. The last U.S. doses of Janssen COVID-19 Vaccine expired May 7, 2023.

Last reviewed: August 31, 2024

In 2018, FDA licensed Vaxelis for use in children age 6 weeks through 4 years: it is indicated as a 3-dose series for infants at ages 2, 4, and 6 months. ACIP voted to add Vaxelis to the Vaccines for Children (VFC) Program in 2019.

The MSP Vaccine Company was created as a joint venture between Merck and Sanofi Pasteur to produce Vaxelis. Vaxelis contains the same DTaP components as Pentacel (Sanofi Pasteur). The IPV component is the same as IPOL (Sanofi Pasteur). The Hib component is the same as PedvaxHIB (Merck), but in a decreased amount. The HepB component is the same as the pediatric formulation of Recombivax HB (Merck), but in an increased amount. Vaxelis is a liquid vaccine that does not require reconstitution.

The complete recommendations for the use of Vaxelis are available at: www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6905a5-H.pdf.

Last reviewed: July 15, 2023

Yellow fever is contraindicated for people who have a history of a severe (anaphylactic) allergy to eggs.

ACIP and CDC no longer consider egg allergy of any severity to be a contraindication or precaution to egg-based influenza vaccines. A person with egg allergy of any severity may receive any influenza vaccine that is appropriate for the person’s age and health status. When administering an egg-based influenza vaccine to a person with egg allergy of any severity, no additional safety precautions are needed, beyond those recommended when administering any vaccine to any recipient.

For more details about giving influenza vaccine to people with a history of egg allergy, go to www.cdc.gov/acip-recs/hcp/vaccine-specific/flu.html for a link to the current ACIP recommendations for influenza vaccination.

Last reviewed: September 19, 2022

If Tdap is administered earlier in pregnancy, it should not be repeated between 27 and 36 weeks’ gestation; only one dose is recommended during each pregnancy.

Last reviewed: October 31, 2023

CDC recommends that refrigerator and freezer temperature logs be kept for at least 3 years. See page 10 of the Vaccine Storage and Handling Toolkit, available at www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf. The reasoning is that it is useful to be able to look back at the record to help determine if a unit is developing a problem.

Individual state Vaccines For Children (VFC) programs may have additional requirements for retaining temperature logs. You should contact your state program for this information. Contact information for state immunization programs is available at www.immunize.org/coordinators.

Last reviewed: July 26, 2023

ACIP does not recommend routine PCV vaccination of healthy children 60 months of age or older. If there is a school requirement, the simplest solution is to give the child one dose of either PCV15 or PCV20 now. However, health insurance may not pay for this dose. For more information on the ACIP recommendations for pneumococcal vaccination of children, go to CDC’s summary of pneumococcal vaccine recommendations: www.cdc.gov/vaccines/vpd/pneumo/hcp/who-when-to-vaccinate.html.

Last reviewed: November 13, 2024

No. IgM tests for acute DENV infection are not sufficiently accurate to be acceptable evidence for the purposes of vaccination. These tests may be falsely positive as a result of other flavivirus infections that may cause similar symptoms (such as Zika).

Acceptable evidence of acute infection with DENV is either a positive dengue RT-PCR test result, or a positive dengue NS1 antigen test result.

Visit CDC’s website on laboratory testing requirements for vaccination with Dengvaxia for additional information: www.cdc.gov/dengue/vaccine/hcp/testing.html.

Last reviewed: February 16, 2022

Pregnant people between 32 and 36 weeks and 6 days’ gestation during the months of September through January in the United States should get one dose of the Pfizer RSVpreF vaccine (Abrysvo) to protect their babies during their first RSV season after birth. Only Abrysvo is FDA-approved and recommended for pregnant people. Arexvy (by GSK) and mResvia (Moderna) are not approved and should not be given during pregnancy.

In most of the continental United States, maternal RSV vaccine is recommended only September through January. Those who provide health care to pregnant people who live in areas with different patterns of RSV seasonality, such as Alaska, Hawaii, parts of Florida, or other jurisdictions outside the continental United States, should follow guidance from state or territorial public health authorities about the timing of RSV vaccination during pregnancy in their regions.

RSV vaccine is only recommended as a single dose; revaccination is not recommended. However, RSV vaccination during one pregnancy is not expected to protect infants resulting from future pregnancies. Therefore, a person who is currently pregnant and received RSV vaccine before the current pregnancy should be counseled that their infant should receive nirsevimab (Beyfortus, Sanofi) for prevention of RSV disease after birth.

Last reviewed: August 25, 2024

Yes, they should receive a booster dose at age 16. A booster dose of MenACWY is recommended at age 16 years even if 2 (or more) doses of MenACWY vaccine were received before age 16 years. First-year college students living in a residence hall who have not received a dose of MenACWY on or after age 16 years, should also be vaccinated.

Last reviewed: November 15, 2024


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Last reviewed: April 6, 2023

There should be a minimum of 4 weeks between the doses in such situations.

Last reviewed: August 11, 2024

A mild case of chickenpox produces immunity to varicella as does a moderate or severe case. A child with a reliable history of chickenpox does not need to receive varicella vaccine. However, if there is any doubt that the mild illness really was chickenpox, it is best to vaccinate the child. There is no harm in vaccinating a child who is already immune.

Last reviewed: May 16, 2023

Yes, a number of studies indicate that the two brands of HepA, Havrix (GSK) and Vaqta (Merck), are interchangeable.

Last reviewed: June 25, 2023

If the first dose is given at age 13 through 15 years, you can give the booster dose as early as age 16 years, with a minimum interval of 8 weeks from the previous dose. So even if the patient was vaccinated at age 15 years 11 months, you could wait at least 8 weeks and then give the booster at age 16 years 1 month (or later).

Last reviewed: November 15, 2024

Allergy to egg is not a contraindication for MMR vaccine. Although measles and mumps vaccines are grown in chick embryo tissue culture, several studies have documented the safety of these vaccines in children with severe egg allergy.

Last reviewed: August 29, 2022

Do not give rotavirus vaccine to an infant who has a history of a severe allergic reaction (for example, anaphylaxis) after a previous dose of rotavirus vaccine or to a vaccine component. The oral applicator for Rotarix contains natural latex rubber so infants with a severe (anaphylactic) allergy to latex should not be given Rotarix; the RotaTeq (Merck) dosing tube is latex-free. Rotavirus vaccine is contraindicated in infants with the rare disorder severe combined immunodeficiency (SCID) and in infants with a history of intussusception.

Practitioners should consider the potential risks and benefits of administering rotavirus vaccine to infants with known or suspected altered immunocompetence, including those whose mothers received immunosuppressive biologics (such as infliximab) during pregnancy. Consultation with an immunologist or infectious diseases specialist is advised.

Children and adults who are immunocompromised because of congenital immunodeficiency, hematopoietic stem cell transplantation, or solid organ transplantation sometimes experience severe or prolonged rotavirus gastroenteritis. However, few safety or efficacy data are available for the administration of rotavirus vaccine to infants who are immunocompromised or potentially immunocompromised, including 1) infants with primary and acquired immunodeficiency, cellular immunodeficiency, and hypogammaglobulinemia and dysgammaglobulinemia; 2) infants with blood dyscrasias, leukemia, lymphomas, or other malignant neoplasms affecting the bone marrow or lymphatic system; 3) infants on immunosuppressive therapy (including high-dose systemic corticosteroids); and 4) infants who are HIV-exposed or infected.

Last reviewed: June 7, 2023

Hib invasive disease does not always result in development of protective antibody levels. Children younger than 24 months of age who develop invasive Hib disease should be considered susceptible and should receive Hib vaccine. Vaccination of these children should start as soon as possible during the convalescent phase of the illness. A complete series as recommended for the child’s age should be administered.

Last reviewed: July 31, 2022

Both IM and SC vaccines may be given through a tattoo.

Last reviewed: December 28, 2022

Measles vaccine, given as MMR, may be effective if given within the first 3 days (72 hours) after exposure to measles. Immune globulin may be effective for as long as 6 days after exposure. Postexposure prophylaxis with MMR vaccine does not prevent or alter the clinical severity of mumps or rubella. However, if the exposed person does not have evidence of mumps or rubella immunity they should be vaccinated since not all exposures result in infection.

Last reviewed: June 19, 2023

A person who has never been exposed to varicella virus through infection or vaccination with varicella vaccine or zoster vaccine live is not at risk for shingles. Shingrix has not been evaluated for the prevention of primary infection with varicella virus. People who have never had chickenpox are recommended to receive 2 doses of varicella vaccine.

Serologic studies indicate that about 99% of people born before 1980 worldwide have had chickenpox even though many cannot recall having had chickenpox (www.cdc.gov/mmwr/preview/mmwrhtml/rr5705a1.htm). As a result, there is no need to ask immunocompetent people age 50 years and older for their varicella disease history or to perform a laboratory test for serologic evidence of prior varicella disease.

Immunocompromised adults age 19 years and older without evidence of exposure to live varicella virus through a history of chickenpox, zoster, or documentation of vaccination with live varicella vaccine (Varivax or ProQuad, Merck) or zoster vaccine live (Zostavax, Merck) should be evaluated further. Birth before 1980 is not sufficient proof of immunity for immunocompromised adults. For immunocompromised adults, evidence of immunity to varicella (confirming need for RZV) includes:

  • Documentation of two doses of varicella vaccine, or
  • Laboratory evidence of immunity or laboratory confirmation of disease, or
  • Diagnosis or verification of a history of varicella or herpes zoster by a healthcare provider.

For any adult who is clinically determined to be susceptible to primary varicella infection, refer to the ACIP varicella vaccine recommendations for further guidance, including post-exposure prophylaxis guidance for immunocompromised adults: www.cdc.gov/mmwr/preview/mmwrhtml/rr5604a1.htm.

CDC has published clinical considerations for shingles vaccination of immunocompromised patients who lack evidence of immunity to chickenpox: www.cdc.gov/shingles/vaccination/immunocompromised-adults.html#special-populations.

Last reviewed: March 9, 2022

PreHevbrio (VBI) was approved by the FDA in November 2021 for people age 18 years and older. It is a triple-antigen (containing S, Pre-S1, and Pre-S2 HBV surface proteins) recombinant vaccine produced in mammalian cells (Chinese hamster ovary cells), and containing an alum adjuvant. It is given intramuscularly in a 3-dose series of 1.0 mL (10 mcg) doses administered on a 0-, 1-, and 6-month schedule. The most common side effects of vaccination are injection site pain and tenderness, as well as fatigue, muscle aches, and headache.

PreHevbrio was approved based on clinical trials conducted in adults age 18 years and older that compared seroprotection rates (SPR, defined as anti-HBs of 10 mIU or higher, and indicative of protection against HBV infection) following 3 doses of PreHevbrio to rates following 3 doses of Engerix-B (GSK). The SPR for PreHevbrio among adults age 18 years or older ranged from 83.6% to 99.2% (overall, 91.2% for all adults) compared to Engerix-B, which ranged from 64.7% to 91.1% (overall, 76.5% for all adults).

PreHevbrio was included as an option for HepB vaccination of adults age 18 years or older in the current ACIP recommendations published on April 1, 2022: www.cdc.gov/mmwr/volumes/71/wr/pdfs/mm7113a1-H.pdf.

The package insert for PreHevbrio is available here: www.fda.gov/media/154561/download.

Last reviewed: July 21, 2023

Yes. Vaxelis may be used for children younger than age 5 years requiring a catch-up primary series, using appropriate minimum intervals. It is not approved as the booster dose of DTaP [dose 4 or 5] or IPV [dose 4] or Hib [dose 4]. If Vaxelis is inadvertently given as a booster dose, it may count as valid and does not need to be repeated.

Last reviewed: July 15, 2023

There are two basic products that can be used in children younger than age 7 years (DTaP and DT) and two that can be used in older children and adults (Td and Tdap). Some people get confused between DTaP and Tdap and others get confused between DT and Td. Here’s a hint to help you remember. The pediatric formulations usually have 3–5 times as much of the diphtheria component than what is in the adult formulation. This is indicated by an upper-case “D” for the pediatric formulation (i.e., DTaP, DT) and a lower case “d” for the adult formulation (Tdap, Td). The amount of tetanus toxoid in each of the products is equivalent, so it remains an upper-case “T.”

Last reviewed: March 31, 2022

Vaccines from your supply should not be routinely transported. In instances where the transport of vaccine from your supply is necessary, take appropriate precautions to protect your supply. Vaccines should only be transported using appropriate packing and temperature monitoring materials that provide the maximum protection. CDC provides detailed guidance on the transport of vaccines in the Storage and Handling Toolkit, pages 23–26 at www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf. See the addendum of the Toolkit for additional instructions concerning COVID-19 and mpox vaccines.

Last reviewed: July 26, 2023

VISs are required to be given and documented when any vaccine covered by the National Childhood Vaccine Injury Act (NCVIA) is given to a person of any age in any setting, including influenza vaccine. CDC recommends that VISs should be given and documented any time any vaccine is administered, regardless of the recipient’s age and setting.

Current VISs are available from the CDC’s website at www.cdc.gov/vaccines/hcp/vis/index.html and from the Immunize.org website at www.immunize.org/vaccines/vis-translations/spanish/, where you will also find many VIS translations in other languages.

Last reviewed: April 10, 2024

Yes. The 2020 ACIP recommendations for MenB include a booster dose schedule for MenB vaccination of people at high risk for meningococcal serogroup B disease. The first booster dose is recommended one year after completion of the primary series, with a subsequent booster dose administered every 2–3 years thereafter, as long as risk remains. Because MenB vaccine brands are not interchangeable, all doses, including booster doses, should be of the same MenB brand. If the brand of the primary series is not known or not available, CDC recommends restarting the primary series with the available product.

Penbraya (MenABCWY, Pfizer) contains MenB-Fhbp (Trumenba) and is given as two doses, 6 months apart, when vaccination against all 5 serogroups is needed. For this 11-year-old child at increased risk of meningococcal disease, Penbraya may be used for MenACWY and MenB (Trumenba) doses (including booster doses) if both vaccines would be given on the same clinic day and at least 6 months have elapsed since the most recent Penbraya dose.

Last reviewed: March 24, 2024

Patients with a negative test should be re-tested every 1 or 2 years (while remaining between the ages of 9 through 16 years) or based on the clinical judgment of the health care provider.

CDC recommends that children and adolescents who are acutely ill with dengue virus infection should wait at least 6 months after the date dengue virus infection is confirmed to begin the vaccine series. https://www.cdc.gov/dengue/hcp/vaccine/schedule-dosing.html.

Last reviewed: February 16, 2022

No. Only the Pfizer (Abrysvo) RSV vaccine is recommended for pregnant people. The GSK RSV vaccine (Arexvy) and the Moderna vaccine (mResvia) are not licensed or recommended for use in pregnancy.

If Arexvy or mResvia is inadvertently administered during pregnancy, do NOT administer a dose of Abrysvo. Instead, CDC recommends that the infant (if younger than 8 months) should receive nirsevimab during RSV season (October through March in most of the continental United States). Treat the infant in the same manner as an infant born to a mother who did not receive RSV vaccination during pregnancy.

CDC strongly urges that this type of administration error be reported to the Vaccine Adverse Event Reporting System, VAERS (https://vaers.hhs.gov). Prevent administration errors with health care provider training on the different indications for each RSV prevention product (both vaccines and the nirsevimab preventive antibody for infants), and always check product labels at least three times before administration to verify that the correct product is being administered to the patient. Consider implementing other feasible safeguards in your system (e.g., electronic alerts) to prevent such errors.

For additional information about this type of error, see the CDC Clinician Outreach and Communication Activity (COCA) Now update from January 22, 2024:  https://emergency.cdc.gov/newsletters/coca/2024/012224.html

Last reviewed: August 25, 2024

No. No data exist at this time to indicate that people younger than 19 who smoke are at increased risk of pneumococcal disease.

Last reviewed: November 13, 2024

Menveo is approved for adults through age 55 years. MenQuadfi was approved in 2020 for ages 2 years and older. If MenACWY is indicated for a person older than age 55 and you do not have MenQuadfi, use Menveo. If meningococcal B vaccination with MenB-FHbp (Trumenba) is needed at the same visit, Penbraya (MenABCWY, Pfizer) is also an option, as long as it has been at least 6 months since the most recent dose of Penbraya.

Last reviewed: November 15, 2024

The “two-vial” formulation of Menveo (MenACWY-CRM, GSK) requires reconstitution of a lyophilized powder with a diluent: it is FDA-licensed for administration to individuals age 2 months through 55 years. The “one-vial” liquid formulation of Menveo licensed in 2022 is essentially the same vaccine, but does not require reconstitution before administration; however, this formulation is currently licensed only for administration to people age 10 through 55 years.

If the “one-vial” formulation is inadvertently administered to a child younger than age 10 years, this incident should be reported to the Vaccine Adverse Event Reporting System (VAERS, https://vaers.hhs.gov) as a vaccine administration error; however, the dose may be counted as valid and should not be repeated. If your facility stocks both one-vial and two-vial Menveo formulations, review practices and protocols and ensure clear labeling of vaccines in storage units to minimize the risk of administering the one-vial formulation to a child younger than age 10 years.

Note that administration of a dose of either Menveo formulation to a patient who is older than the FDA-licensed upper age limit of 55 years should not be reported to VAERS and is not considered an error. This is because ACIP recommendations state that Menveo may be administered to adults age 56 or older when MenACWY vaccination is indicated and MenQuadfi (MenACWY-TT, Sanofi, licensed with no upper age limit) is not available.

Last reviewed: November 15, 2024

CDC has included in the Vaccine Storage and Handling Toolkit an addendum that contains additional details concerning special considerations for COVID-19 and mpox vaccines. This is available at www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf.

Last reviewed: July 26, 2023

Eculizumab (Soliris) and related long-acting compounds, such as ravulizumab (Ultomiris) and sutimlimab (Enjaymo), inhibit the terminal complement pathway. People with persistent complement component deficiency due to an immune system disorder or use of a complement inhibitor are at increased risk for meningococcal disease even if fully vaccinated. This patient should be given a 2-dose primary series of MenACWY vaccine (2 doses separated by at least 8 weeks) and a 3-dose series of MenB vaccine (0, 1-2 months, and 6 months). The patient should receive regular booster doses of MenACWY and MenB as long as he remains at risk: a booster dose of MenACWY every 5 years and a booster dose of MenB one year after completion of the primary series, followed by a booster dose of MenB every 2–3 years thereafter. The same type of MenB vaccine must be used for all doses, including booster doses; MenB products are not interchangeable.

Penbraya (MenABCWY, Pfizer) contains MenB-Fhbp (Trumenba, Pfizer) and is given as two doses, 6 months apart, when vaccination against all 5 serogroups is needed. For people age 10 years or older at increased risk of meningococcal disease, like this patient, Penbraya may be used for MenACWY and MenB (Trumenba) doses (including booster doses) if both vaccines would be given on the same clinic day and at least 6 months have elapsed since most recent Penbraya dose.

Because patients treated with complement inhibitors can develop invasive meningococcal disease despite vaccination, clinicians using these products also may consider antimicrobial prophylaxis for the duration of complement inhibitor therapy.

Last reviewed: November 15, 2024

Because more than one type or subtype of influenza virus can circulate in any given influenza season, providers should offer influenza vaccination to unvaccinated people throughout the influenza season, including people who may have had an influenza illness already in the season.

Last reviewed: August 11, 2024

Varicella vaccine is most effective in preventing chickenpox or reducing the severity of the disease if used within 72 hours (3 days), and may still be helpful up to 5 days after exposure. However, not every exposure to varicella leads to infection, so for future immunity, varicella vaccine should be given to a person age 12 months or older who does not have a contraindication to vaccination, even if more than 5 days have passed since an exposure.

Last reviewed: May 16, 2023

There are two different DTaP products currently used in the U.S. for the primary series for children ages 2 months through 6 years (Daptacel [Sanofi] and Infanrix [GSK]). ACIP has recommended that, whenever feasible, healthcare providers should use the same brand of DTaP vaccine for all doses in the vaccination series. If vaccination providers do not know or have available the type of DTaP vaccine previously administered to a child, any DTaP vaccine may be used to continue or complete the series. For vaccines in general, vaccination should not be deferred because the brand used for previous doses is not available or is unknown (see the ACIP’s General Best Practices Guidance for Immunization at www.cdc.gov/vaccines/hcp/acip-recs/general-recs/timing.html).

Last reviewed: March 31, 2022

Infliximab is an IgG monoclonal antibody that neutralizes the biological activity of tumor necrosis factor-alpha. Like other IgG antibodies infliximab crosses the placenta. Infliximab has been detected in the blood of infants up to 6 months following birth. Consequently, these infants may be at increased risk of serious infection.

Neither ACIP nor CDC provides specific guidance on this issue because there are few data on safety or efficacy in children exposed to potentially immunosuppressive biologics during pregnancy. As noted above, practitioners should consider the potential risks and benefits of administering rotavirus vaccine to infants with known or suspected altered immunocompetence. Consultation with an immunologist or infectious diseases specialist is advised.

The manufacturer recommends that live vaccines (rotavirus and BCG) be deferred for at least six months after birth for infants whose mothers received infliximab during pregnancy. Hence, if a practitioner follows the manufacturer’s recommendation the child would not be eligible to receive rotavirus vaccine because according to ACIP guidelines the rotavirus vaccine series should not to be started after age 15 weeks 0 days.

Inactivated vaccines should be given on schedule.

Last reviewed: June 7, 2023

Hib meningitis incidence historically peaked at a younger age (4–6 months) among AI/AN infants than among other U.S. infant populations (6–7 months). Vaccination with a primary series of PedvaxHib (PRP-OMP, Merck) is preferred for AI/AN infants because this vaccine can produce a protective antibody response after the first dose.

At the current time, it is unknown whether Vaxelis (DTaP-IPV-Hib-HepB), which contains a smaller quantity of PRP-OMP than PedvaxHib, produces a similar protective antibody response after the first dose. Therefore, Vaxelis is not preferred for AI/AN infants at this time.

Last reviewed: July 31, 2022

ACIP recommends a 3-dose Dengvaxia vaccine schedule, with doses administered at 0, 6 months, and 12 months.

Last reviewed: February 16, 2022

No. ACIP does not recommend aspiration when administering vaccines because no data exist to justify the need for this practice. There are data that show that aspiration is more painful for the vaccine recipient. IM injections are not given in areas where large vessels are present. Given the size of the needle and the angle at which you inject the vaccine, it is difficult to cannulate a vessel without rupturing it and even more difficult to actually deliver the vaccine intravenously. We are aware of no reports of a vaccine being administered intravenously and causing harm in the absence of aspiration.

Last reviewed: December 28, 2022

Yes. Adults with a history of herpes zoster should receive Shingrix. If a person is experiencing an episode of zoster, vaccination should be delayed until the acute phase of the illness is over and symptoms abate.

Last reviewed: March 9, 2022

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