Ask the Experts is one of our most popular destinations for healthcare professionals. Our experts provide clear, easy-to-understand answers to commonly asked questions about vaccines and their use.
The ACIP statement (“Human Rabies Prevention-United States, 2008, Recommendations of the Advisory Committee on Immunization Practices”) was published in MMWR on May 23, 2008. This document updated the status of rabies and anti-rabies biologics in the United States. To view this document, go to www.cdc.gov/mmwr/PDF/rr/rr5703.pdf.
In March 2010, ACIP eliminated the fifth dose of vaccine given post-exposure to previously unvaccinated persons with no immunosuppression. To view these recommendations, go to www.cdc.gov/mmwr/pdf/rr/rr5902.pdf.
In May 2022, ACIP eliminated the third dose of vaccine given in the primary series for pre-exposure prophylaxis and introduced updated risk categories with customized recommendations for long-term follow up after completion of the 2-dose primary series. To view this document, visit www.cdc.gov/mmwr/volumes/71/wr/pdfs/mm7118a2-H.pdf.
In April 2018, the Advisory Committee on Immunization Practices (ACIP) published a compilation of all previous recommendations for the prevention of pertussis, tetanus, and diphtheria (MMWR 2018;678 [RR-2]:1-31). The document can be accessed on the CDC website at www.cdc.gov/mmwr/volumes/67/rr/pdfs/rr6702a1-H.pdf.
In January 2020, ACIP published updated Tdap recommendations, stating that either Td or Tdap may be used in situations where Td only was previously recommended. The document can be accessed on the CDC website at www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6903a5-H.pdf.
HBV is stable in the environment and remains viable for 7 or more days on environmental surfaces at room temperature. HBV can be transmitted despite the absence of visible blood. Any high level disinfectant that is tuberculocidal will inactivate HBV. The Environmental Protection Agency also registers disinfectants specifically approved for use against HIV and HBV; a current list is available at this website: www.epa.gov/pesticide-registration/list-d-epas-registered-antimicrobial-products-effective-against-human-hiv-1.
Yes, although the package inserts states that Pediarix should only be given to infants born to mothers who are HBsAg-negative, ACIP voted in 2003 to expand its recommendations for use to include infants born to women whose HBsAg status is positive or unknown beginning no earlier than age 6 weeks.
Yes. Death as a result of fulminant hepatic failure is rare, however, older age (over 40 years) and preexisting chronic liver disease increases the risk of severe disease and death from hepatitis A. The person-to-person U.S. multistate outbreaks that began in 2016 have disproportionately affected adults with chronic liver disease and other health problems related to drug use and unstable housing. From 2016 through June 2023, CDC received reports of nearly 45,000 cases of acute HAV infection. Of these, approximately 61% have been hospitalized and nearly 1% (more than 420 people) have died.
ACIP recommendations and package inserts do not always match. Occasionally, ACIP may use different data to formulate its recommendations, or try to add flexibility to its recommendations (as was the case in this situation), which results in a recommendation different than the package insert. Published recommendations of national advisory groups (such as ACIP or AAP’s Committee on Infectious Diseases) should be considered equally as authoritative as those on the package insert. You should consider 8 months 0 days as the maximum age for a dose of rotavirus vaccine.
In June 2021, ACIP voted to recommend Dengvaxia for routine use in children age 9 through 16 years with laboratory-confirmed previous dengue virus infection and living in areas where CDC has classified dengue as endemic. The recommendation is only for persons with confirmed previous DENV infection because Dengvaxia is associated with an increased risk for severe dengue in those who experience their first natural infection (i.e., primary infection) after vaccination.
The vaccine is not approved for use in U.S. travelers who are visiting but not living in an area where dengue is common.
The most current ACIP recommendations for Dengvaxia are available at www.cdc.gov/mmwr/volumes/70/rr/pdfs/rr7006a1-H.pdf.
CDC has developed a pre-vaccination checklist for evaluating whether a child should receive Dengvaxia: www.cdc.gov/dengue/resources/DVBD_FS_Vaccination_Checklist-508.pdf.
The Advisory Committee on Immunization Practices (ACIP) considers evidence of immunity to varicella to be:
*Note: Although there is only a very small chance of susceptibility, due to the potential for severe consequences from varicella infection, year of birth is not accepted as evidence of varicella immunity for healthcare personnel, immunosuppressed people, and pregnant people.
Acceptable presumptive evidence of immunity against measles includes at least one of the following:
Although birth before 1957 is considered acceptable evidence of measles immunity, healthcare facilities should consider vaccinating unvaccinated personnel born before 1957 who do not have other evidence of immunity with 2 doses of MMR vaccine (minimum interval 28 days).
During an outbreak of measles, healthcare facilities should recommend 2 doses of MMR vaccine at the appropriate interval for unvaccinated healthcare personnel regardless of birth year if they lack laboratory evidence of measles immunity.
ACIP recommends annual vaccination for all people ages 6 months and older who do not have a contraindication to influenza vaccination.
Tick-borne encephalitis (TBE) is a disease caused by a flavivirus transmitted by tick bite in certain areas of Europe and Asia. It may also be transmitted through the consumption of unpasteurized milk or cheese from infected cows, goats, or sheep. CDC provides details of TBE-endemic areas, but notes that the risk of TBE in endemic areas is variable within risk areas and from year-to-year. Additional geographic information is available from CDC: www.cdc.gov/tick-borne-encephalitis/data-maps/.
Travelers moving or traveling to a TBE-endemic area and likely to have extensive exposure to ticks based on their planned outdoor activities and itinerary should be vaccinated for TBE. TBE vaccination may be considered for other travelers to TBE-endemic areas based on their likely exposure to ticks during their activities, their risk of a poor health outcome, and their personal perception and tolerance of risk.
ACIP recommends routine administration of a conjugate Hib vaccine series for all infants beginning at age 2 months. Infants 2 through 6 months of age should receive a 3-dose series of ActHIB, Hiberix, Pentacel, or Vaxelis, or a 2-dose series of PedvaxHIB. The first dose can be administered as early as age 6 weeks, but not earlier. Hib-containing vaccine should not be given before 6 weeks of age. Doses given before 12 months of age should be separated by at least 4 weeks. A booster dose (which will be dose 3 or 4 depending on vaccine type used in primary series) of any Hib-containing vaccine is recommended at age 12 through 15 months and at least 8 weeks after the most recent Hib dose. Vaxelis is recommended only for the primary Hib series and is not recommended for use as a booster (4th) dose. A different Hib-containing vaccine licensed for a booster dose should be used.
Medically stable preterm infants should be vaccinated beginning at age 2 months according to the schedule recommended for other infants, on the basis of chronological age. For special situations in children, refer to the current CDC recommended immunization schedule Hib notes: www.cdc.gov/vaccines/hcp/imz-schedules/child-adolescent-notes.html.
Vaccines must always be dispensed with a prescription or order from a physician or other healthcare provider authorized by the state to prescribe medications. However, there are situations where vaccines can be administered using a standing order or vaccine protocol that is not patient-specific. In these situations, a physician or other healthcare provider does not need to be physically present for the vaccine to be administered. Several studies have shown that the use of standing orders can improve vaccination rates, and ACIP recommends the use of standing orders programs in both outpatient and inpatient settings. A comprehensive set of standing orders for the routine vaccines given to children and adults can be found at www.immunize.org/clinical/topic/standing-orders-templates/.
Yes. Vaccination should be offered regardless of history of prior SARS-CoV-2 infection or long COVID.
Because COVID-19 illness temporarily boosts immunity, people who have recently had SARS-CoV-2 infection may consider delaying a 2025–2026 COVID-19 vaccine dose by up to 3 months following symptom onset or positive COVID-19 test (if asymptomatic). Studies have shown that a longer time between infection and vaccination may improve the immune response to vaccination. The likelihood of reinfection in the first few months following infection is low.
A recipient’s individual risks for severe disease and current COVID-19 conditions in the community should be taken into account when deciding whether to delay vaccination up to 3 months after infection. As with all vaccines, vaccination should be deferred until after recovery from moderate to severe illness.
Yes. Several studies have measured the effect of vaccination on preventing RSV-associated hospitalizations among people vaccinated in the first RSV season after the recommendation for use of the vaccine. Estimates were similar for both the GSK and Pfizer products and showed that they reduced the risk of hospitalization among recipients overall by between 75% and 82%. For additional details, see the CDC MMWR published in August 2024: www.cdc.gov/mmwr/volumes/73/wr/pdfs/mm7332e1-H.pdf .
Yes.
In studies of the real-world effectiveness of Arexvy during the 2023–24 RSV season, the first since licensure of Arexvy, Arexvy was approximately 77% effective in preventing RSV-associated emergency department encounters and 83% effective in preventing RSV-associated hospitalizations in adults age 60 and older.
In studies of the real-world effectiveness of Abrysvo during the 2023–24 RSV season, the first RSV season since licensure, Abrysvo was approximately 79% effective in preventing RSV-associated emergency department encounters and 73% effective in preventing RSV-associated hospitalizations in adults age 60 and older.
The Moderna mResvia vaccine was first used during the 2024–25 season. Real-world effectiveness data are not yet available.
For additional details, see the CDC MMWR published in August 2024: www.cdc.gov/mmwr/volumes/73/wr/pdfs/mm7332e1-H.pdf.
People who are at increased risk for acquiring HAV infection include the following:
No vaccine component, including the diluent used to reconstitute a vaccine, should be stored in vegetable bins, nor in the space occupied by vegetable bins of a household-style refrigerator. CDC recommends that you position vaccines and diluents 2 to 3 inches from the unit walls, ceiling, floor, and door. If using a household-style unit, avoid storing vaccines and diluents in any part of the unit that may not provide stable temperatures or sufficient air flow, such as directly under cooling vents; in deli, fruit, or vegetable drawers; or on refrigerator door shelves. The instability of temperatures and air flow in these areas may expose vaccines to inappropriate storage temperatures. For more information, refer to page 14 of the CDC Vaccine Storage and Handling Toolkit available at www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf.
Yes. Dengvaxia is included in the VFC program. The most current VFC resolution is available at www.cdc.gov/vaccines-for-children/about/index.html.
The cost of the pre-vaccination screening test will be covered by Medicaid for those who are eligible.
Currently, protection from serious lower respiratory tract disease (LRTD) after RSV vaccination is expected to last for at least two RSV seasons, but exactly how well it protects over a longer period of time is not yet known. In clinical trials, the ability of the vaccine to reduce the risk of serious lower respiratory tract disease was tested in some people over 2 RSV seasons, and all RSV vaccines provided meaningful protection in the second season.
RSV vaccination is currently recommended as a single dose: revaccination is not yet recommended. ACIP will update its recommendations concerning whether to revaccinate, and when, as more data become available over time concerning how long protection from a single dose lasts and how effective revaccination is in boosting protection. A small study by GSK did not show a meaningful benefit of revaccination with Arexvy just one year after dose 1; however, revaccinating after a longer interval might be helpful. Studies are underway to evaluate the benefit of revaccination at different intervals.
Use the date of administration to make a presumptive determination of what type of OPV was received. Only trivalent doses count as valid for the U.S. polio vaccination schedule.
Trivalent OPV was used throughout the world before April 2016. In April 2016, all countries using tOPV switched to bivalent OPV (bOPV). In addition, some countries also use monovalent OPV (mOPV) during special vaccination campaigns. Doses recorded as bOPV or mOPV, and unspecified OPV doses noted on an immunization record as given during a vaccination campaign, do not count as valid doses for the U.S. polio vaccination schedule.
You may count a record of an “OPV” dose as valid if the dose was administered before April 1, 2016, and was not noted as being administered as part of a mass vaccination campaign. OPV doses administered on or after April 1, 2016, should not be counted as a valid dose for the U.S. polio vaccination schedule.
No, do not use the same unit. Frequent opening of the refrigerator door to retrieve food items can adversely affect the internal temperature of the unit and potentially damage the vaccines.
FDA licensed the first pneumococcal conjugate vaccine against seven serotypes (PCV7, Prevnar7, Pfizer) in 2000. A large clinical trial showed PCV7 reduced invasive disease caused by vaccine serotypes by 97%. Compared to unvaccinated children, children who received PCV7:
FDA licensed PCV13 based on studies comparing the serologic response of children who received PCV13 to those who received PCV7. Substantial evidence demonstrates that routine infant PCV7 and PCV13 vaccination reduces the carriage and transmission of vaccine serotypes.
Researchers conducted a randomized placebo-controlled trial (CAPiTA trial) in the Netherlands among approximately 85,000 adults 65 years or older from 2008 through 2013. This trial evaluated the clinical benefit of PCV13 in the prevention of pneumococcal pneumonia. The results of the CAPiTA trial demonstrated:
FDA licensed PCV15 and PCV20 in 2021 based on studies comparing the serologic response of adults who received either PCV15 or PCV20 to those who received PCV13. These studies showed PCV15 and PCV20 induced antibody levels comparable to those induced by PCV13 and shown to be protective against invasive disease. FDA subsequently expanded the indication for use of PCV15 and PCV20 to include children starting at age 6 weeks in 2022 and 2023, respectively, based on serologic studies. PCV21 was licensed in 2024 based on a similar evaluation of serologic response to vaccination.
Yes. In clinical trials among immunocompetent adults age 50 years or older, Shingrix reduced the risk of PHN by 91%. One study among hematopoietic stem cell transplant recipients reported that vaccination reduced the risk of PHN by 89%.
Gardasil 9 (9vHPV, Merck) is the only HPV vaccine being distributed in the United States. Bivalent Cervarix (2vHPV, GSK) and quadrivalent Gardasil (4vHPV, Merck) are no longer available in the United States.
9vHPV is an inactivated 9-valent vaccine licensed by the FDA in 2014. It contains 7 oncogenic (cancer-causing) HPV types (16, 18, 31, 33, 45, 52, and 58) and two HPV types that cause most genital warts (6 and 11). The 9vHPV vaccine is licensed for people age 9 through 45 years.
Two or more injectable or nasally administered live vaccines not administered on the same day should be separated by at least 4 weeks to minimize the potential risk for interference. If two such vaccines are separated by less than 4 weeks, the second vaccine administered should not be counted and the dose should be repeated at least 4 weeks later. Alternatively, one can perform serologic testing to check for immunity, but this option may be more costly, may not be practical if multiple antigens are involved (such as measles, mumps and rubella), and may provide results that are difficult to interpret.
In cases where the vaccine doses given less than 28 days apart are two doses of the same live vaccine in a series (e.g., 2 doses of MMR vaccine), not different vaccines, you do not need to repeat the second dose if it was inadvertently administered within the 4-day “grace period” before day 28. If given more than 4 days earlier than day 28, the second dose should be repeated after the recommended minimum interval from the invalid dose.
The oral vaccines Ty21a typhoid, cholera and rotavirus vaccines can be administered on the same day with or at any interval before or after other live vaccines (injectable or intranasal). However, ACIP recommends that oral cholera vaccine should be administered before Ty21a vaccine, and at least 8 hours should separate the oral cholera vaccine and the first dose of Ty21a in order to minimize the risk that the oral cholera vaccine buffer might interfere with the enteric coating of the oral Ty21a vaccine.
Not that we know. Nearly all vaccines have been reported to be associated with the fainting. Post-vaccination fainting has been most frequently reported after three vaccines commonly given to adolescents (HPV, MenACWY, and Tdap). However, the association with these vaccines may simply reflect the fact that adolescents are generally more likely to experience fainting in response to pain or anxiety.
Treatment after an exposure (PEP) in a previously unvaccinated person requires receiving a dose of human rabies immune globulin (HRIG) and four (or five if the person’s immune system is suppressed) doses of vaccine. Pre-exposure prophylaxis (PrEP) requires only two doses of vaccine and no immune globulin. If a person who is up to date with the recommended PrEP schedule is exposed to rabies, the person’s PEP treatment is completed with two doses of vaccine (on day 0 and day 3).
All children should receive a series of DTaP at ages 2, 4, and 6 months, with boosters at ages 15–18 months and at 4–6 years. The fourth dose may be given as early as age 12 months if at least 6 months have elapsed since the third dose.
ACIP recommends that the rotavirus vaccine series be completed with the same product whenever possible. However, vaccination should not be deferred because the product used for a previous dose is not available or is unknown. In these situations, the provider should continue or complete the series with the product available. If any dose in the series was RotaTeq, or the vaccine product is unknown for any dose in the series, a total of 3 doses of rotavirus vaccine should be administered. The minimum interval between doses of rotavirus vaccine is 4 weeks. All doses should be administered by age 8 months and 0 days.
Since DTaP and pneumococcal conjugate (PCV) are the vaccines most likely to cause a local reaction, it is prudent to give DTaP and PCV in separate limbs (if possible), so there is no confusion about which vaccine caused the reaction.
Yes. As with any combination vaccine, it may be used when any of the components are indicated and none are contraindicated. Providers must observe spacing intervals such that the minimum interval between doses is equal to the greatest interval of any of the individual antigens. Pediarix may only be used in children younger than age 7 years.
No. ACIP recommends giving a dose of MMR to infants age 6 through 11 months before international travel, but not varicella vaccine. Varicella vaccine is neither approved nor recommended for children younger than age 12 months in any situation.
Zero, one, or two doses of MMR vaccine are needed for the adults described below.
Zero doses:
One dose of MMR vaccine:
Two doses of MMR vaccine:
People who previously received a dose of measles vaccine in 1963–1967 and are unsure which type of vaccine it was, or are sure it was inactivated measles vaccine, should be revaccinated with either one (if low-risk) or two (if high-risk) doses of MMR vaccine. If the vaccine given was the live virus vaccine, the dose is considered valid and does not need to be repeated.
* Healthcare personnel born before 1957 should be considered for MMR vaccination in the absence of an outbreak but are recommended for MMR vaccination during outbreaks.
There is no federal law requiring a refusal form. Several major medical organizations, including the American Academy of Pediatrics, have stated that healthcare providers may decide it is in their best interest to formally document a parent’s refusal to accept vaccination for their (minor) child. To read a discussion on this topic and to access a prototype refusal form, see “Record of Vaccine Declination” that can be accessed at www.immunize.org/catg.d/p4059.pdf.
No. ACIP considers a dose of MenACWY given to a 10-year-old child to be valid for the first dose in the adolescent series. Doses given before age 10 years should not be counted. The child should receive the second (booster) dose at age 16 years as usual.
To assist with the shared clinical decision-making around the option to vaccinate against meningococcal serogroup B disease and the timing of vaccination, CDC has provided some specific considerations about the disease and the vaccine that the patient and provider may weigh:
Multiple manufacturers are producing inactivated, recombinant, and live attenuated influenza vaccines for the U.S. market for the 2025–26 season. All vaccines are trivalent (containing two influenza A and one influenza B virus vaccine antigen).
Immunize.org offers a 1-page printable document that summarizes each of the products available for the current influenza vaccination season: www.immunize.org/catg.d/p4072.pdf. Availability of the licensed influenza vaccines packaged in multidose vials (MDVs) containing thimerosal as a preservative vary by manufacturer.
In February 2022, ACIP voted on the following recommendation or TBE vaccination: TBE vaccine is recommended for people who are moving or traveling to a TBE-endemic area and will have extensive exposure to ticks based on their planned outdoor activities and itinerary.
In addition, TBE vaccine may be considered for persons traveling or moving to a TBE-endemic area who might engage in outdoor activities in areas ticks are likely to be found. The decision to vaccinate should be based on an assessment of their planned activities and itinerary, risk factors for a poorer medical outcome, and personal perception and tolerance of risk. For more information about TBE vaccine from CDC, visit www.cdc.gov/tick-borne-encephalitis/hcp/vaccine/index.html.
Yes, for the primary series. If either ActHIB (PRP-T), Hiberix (PRP-T), Vaxelis (DTaP-IPV-Hib-HepB), or Pentacel (DTaP-IPV/Hib) is used for a routine primary series dose, a complete routine primary series consists of three doses. PedvaxHIB (PRP-OMP) requires a 2-dose primary series, but if administering a mixed-product primary series including only one dose of PedvaxHIB, a total of 3 doses is needed to complete the primary series.
Vaxelis is not recommended for use as a Hib booster (4th) dose. A different Hib-containing vaccine licensed for the booster dose should be used. If Vaxelis is inadvertently given as the booster dose, the dose does not need to be repeated with another Hib-containing vaccine, if the proper spacing of prior doses is maintained.
No. According to ACIP, vaccines administered outside the U.S. generally can be accepted as valid if the schedule (i.e., minimum ages and intervals) is similar to that recommended in the U.S. However, with the exception of the influenza and pneumococcal polysaccharide vaccines, only written documentation should be accepted as evidence of previous vaccination. In general, if records cannot be located or will definitely not be available anywhere because of the patient’s circumstances, children without adequate documentation should be considered susceptible and should be started on the age-appropriate vaccination schedule. Serologic testing for immunity is an alternative to vaccination for certain antigens. More information is available in the relevant subsection of CDC’s General Best Practices for Immunization, available at www.cdc.gov/vaccines/hcp/imz-best-practices/special-situations.html#cdc_report_pub_study_section_7-persons-vaccinated-outside-the-united-states.
| Table 1: Hepatitis B laboratory nomenclature | |
| HBsAg: | Hepatitis B surface antigen is a marker of infectivity. Its presence indicates either acute or chronic HBV infection. |
| anti-HBs: | Antibody to hepatitis B surface antigen is a marker of immunity. Its presence indicates an immune response to HBV infection, an immune response to vaccination, or the presence of passively acquired antibody. (It is also known as HBsAb, but this abbreviation is best avoided since it is often confused with abbreviations such as HBsAg.) |
| anti-HBc (total): | Antibody to hepatitis B core antigen is a nonspecific marker of acute, chronic, or resolved HBV infection. It is not a marker of vaccine-induced immunity. It may be used in prevaccination testing to determine previous exposure to HBV infection. (It is also known as HBcAb, but this abbreviation is best avoided since it is often confused with other abbreviations.) |
| IgM anti-HBc: | IgM antibody subclass of anti-HBc. Positivity indicates recent infection with HBV (<6 mos). Its presence indicates acute infection. |
| HBeAg: | Hepatitis B “e” antigen is a marker of a high degree of HBV infectivity, and it correlates with a high level of HBV replication. It is primarily used to help determine the clinical management of patients with chronic HBV infection. |
| Anti-HBe: | Antibody to hepatitis B “e” antigen may be present in an infected or immune person. In persons with chronic HBV infection, its presence suggests a low viral titer and a low degree of infectivity. |
| HBV-DNA: | HBV Deoxyribonucleic acid is a measure of viral load and reflects viral replication. It correlates well with infectivity. It is used to assess and monitor the treatment of patients with chronic HBV infection. |
In general, neither exposure to nor recovery from an infectious disease is a contraindication or precaution to vaccination. In particular, recovery from varicella (chickenpox) is not a reason to withhold a live vaccine, such as MMR. Depending upon the disease involved, it is important to take into account the risk of exposure to other patients or healthcare personnel when deciding where or when to vaccinate a child that may be infectious to others.
Adults age 65 years and older have the highest rates of hospitalization and death from COVID-19 illness. Protection against severe COVID-19 disease wanes after a few months. Disease surveillance data from the United States shows that SARS-CoV-2 viruses circulate and cause illness at varying levels year-round, with waves of activity observed historically in winter and late summer. It is not known whether this pattern will continue. This pattern is not like influenza, which usually causes a single epidemic wave (sometimes with more than one peak) each winter.
The 2025 CDC adult immunization schedule shows that adults age 65 years and older who are vaccinated against COVID-19 are recommended to receive a second dose of any 2025–2026 Formula COVID-19 vaccine 6 months after their first 2025–2026 Formula COVID-19 vaccine dose (minimum interval of 2 months for Comirnaty, Spikevax, and Nuvaxovid; minimum interval of 3 months for mNexspike). The second dose does not have to be the same brand as the first.
CDC recommends waiting a minimum of 8 weeks (2 months) since the last 2024–2025 Formula COVID-19 vaccine to receive an age-appropriate 2025–2026 Formula COVID-19 vaccine, if using Comirnaty (Pfizer-BioNTech), Nuvaxovid (Sanofi-Novavax), or Spikevax (Moderna). They recommend a 3-month minimum interval when using mNexspike (Moderna); however, a dose of mNexspike administered at least 2 months after the most recent dose does not need to be repeated.
Any person who initiated a COVID-19 vaccination initial series (e.g., a child 6 months through 23 months of age or a person with moderate or severe immunocompromise) with a previous formulation should follow the age-appropriate recommended schedule for completion of their primary series with the current formulation of the same brand, if feasible. For the 2025–26 season, Spikevax is the only licensed and recommended option for children age 6 through 59 months, regardless of their vaccination history.
Children with confirmation of previous DENV infection need three doses of Dengvaxia, given 6 months apart, for complete protection (0, 6 months, 12 months). Recipients achieve significant protection following dose 1.
As of 2021, every state has an IIS that is capable of accepting and storing immunization records on individuals of all ages. To find out the status of the IIS in your state you should contact your state IIS program or your state immunization program. CDC maintains a listing of contact information for all state IIS programs at www.cdc.gov/iis/contacts-locate-records/.
With rare exceptions*, all vaccines can be administered at the same visit. There is no upper limit for the number of vaccines that can be administered during one visit. ACIP and AAP consistently recommend that all needed vaccines be administered during an office visit. Vaccination should not be deferred because multiple vaccines are needed. All live vaccines (MMR, varicella, live attenuated influenza, yellow fever, and oral typhoid) can be given at the same visit if indicated. If injectable or intranasal live vaccines are not administered during the same visit, they should be separated by 4 weeks or more.
When giving several injections at a single visit, separate IM vaccines by at least 1 inch in the body of the muscle, if possible, to reduce the likelihood of local reactions overlapping. Here are some helpful site maps for different ages so you can record where shots were given:
For infants and toddlers: www.eziz.org/PDF/IMM-718.pdf
For older children: www.aimtoolkit.org/docs/Giving_all_the_doses_12mths.pdf
For adults: eziz.org/assets/docs/ADA/IMM-718A.pdf
For details see the vaccine administration section of CDC’s “General Best Practices for Immunization”, available at www.cdc.gov/vaccines/hcp/imz-best-practices/vaccine-administration.html.
*There are 2 exceptions to this general rule:
Shingrix (recombinant zoster vaccine, RZV) is recommended for the prevention of herpes zoster and related complications for immunocompetent adults 50 years of age and older, including those who previously received the live zoster vaccine, Zostavax. On October 20, 2021, ACIP recommended 2 doses of RZV for the prevention of herpes zoster and related complications in adults age 19 years or older who are or will be immunodeficient or immunosuppressed because of disease or therapy.
ACIP published its zoster vaccination recommendations for immunocompetent adults age 50 years and older in January 2018: www.cdc.gov/mmwr/volumes/67/wr/pdfs/mm6703a5-H.pdf.
ACIP published its recommendations for the use of recombinant zoster vaccine in adults age 19 years or older who are or will be immunocompromised in January 2022: www.cdc.gov/mmwr/volumes/71/wr/pdfs/mm7103a2-H.pdf.
CDC also has a website with additional clinical considerations for the use of Shingrix in immunocompromised adults: www.cdc.gov/shingles/hcp/vaccine-considerations/immunocompromised-adults.html.
All three RSV vaccines are currently licensed and recommended as a one-time dose for any person. Recommendations for revaccination have not been made. At this time, a pregnant person who receives Abrysvo (Pfizer) during one pregnancy is not recommended to receive Abrysvo during a subsequent pregnancy: in subsequent pregnancies, the baby should receive an RSV preventive antibody after delivery for RSV protection. ACIP will make decisions concerning RSV revaccination as more data become available over time.
First-year college students living in residence halls should be vaccinated against meningococcal ACWY disease. Before enrollment, administer a dose of MenACWY vaccine to those previously unvaccinated, to those who have not had a dose of MenACWY since turning 16, and to those whose most recent MenACWY dose (given after turning 16) was not given within the past 5 years. Some schools, colleges, and universities have policies requiring vaccination against meningococcal disease as a condition of enrollment.
The ACIP recommends that routine HPV vaccination be initiated for all children at age 11 or 12 years. ACIP notes that vaccination may be started at age 9 years, if preferred, and should start at age 9 for any child that the provider at risk of exposure to HPV due to suspected abuse. There is no downside to beginning the series at age 9, and this option is often easier for families and clinics because it gives more time to complete the 2-dose series before the 13th birthday. Vaccination is also recommended for all people age 13 through 26 years who have not been vaccinated previously or who have not completed the vaccination series.
If vaccines are given too close together, it can result in a less than optimal immune response. However, in most instances, a difference of a few days is unlikely to have a negative effect on immune response. With the exception of rabies vaccine, ACIP allows a grace period of 4 days (i.e., vaccine doses administered up to 4 days before the recommended minimum interval or age can be counted as valid). However, if a dose was administered 5 or more days earlier than the recommended minimum interval between doses, it is not valid and must be repeated. The repeat dose should be spaced after the invalid dose by the recommended minimum interval. Note that for hepatitis A vaccination, if the second dose is administered too early and must be repeated, the recommended interval between the invalid dose and the repeat dose is 6 months; however, if the repeat dose is administered earlier than 6 months no further doses are recommended as long as the interval between the first and final dose is at least 6 months.
If the first dose in a series is given 5 days or more before the recommended minimum age, the dose should be repeated on or after the date when the child reaches at least the minimum age. If the vaccine is a live vaccine, ensuring that a minimum interval of 28 days has elapsed from the invalid dose is recommended. Avoid such errors by knowing the minimum intervals and ages for routinely given vaccines. You can look up such information in the ACIP “General Best Practices Guidelines for Immunization”, available at www.cdc.gov/vaccines/hcp/imz-best-practices/timing-spacing-immunobiologics.html, Table 3-2.
The 4-day “grace period” should not be used when scheduling future vaccination visits, and should not be applied to the 28-day interval between different live parenteral vaccines not administered at the same visit. It should be used primarily when reviewing vaccination records (for example, when evaluating a vaccination record prior to entry to daycare or school).
Falls that occur due to fainting after vaccination can be prevented by assuring that the vaccinated person is sitting in a chair or lying down and is observed for 15 minutes following vaccination.
Human rabies immune globulin (HRIG) is the IgG fraction of plasma from human donors who have received multiple doses of rabies vaccine and have high levels of anti-rabies antibody. HRIG is administered once to previously unvaccinated individuals exposed to a rabid animal to provide rabies virus neutralizing antibody coverage until the patient responds to vaccination by actively producing virus-neutralizing antibodies. HRIG is administered once on day 0 at the time postexposure prophylaxis (PEP) is initiated, in conjunction with human rabies vaccine. If HRIG was not administered when vaccination was begun on day 0, it can be administered up to and including day 7 of the PEP series. If anatomically feasible, the full dose of HRIG is infiltrated around and into any wounds. Any remaining volume is injected intramuscularly at a site distant from vaccine administration. HRIG should not be administered in the same syringe or at the same anatomic site as the first vaccine dose. However, subsequent doses (i.e., on days 3, 7, and 14) of vaccine in the 4-dose PEP vaccine series can be administered in the same anatomic location in which HRIG was administered.
Although birth before 1957 is considered acceptable evidence of measles immunity for routine vaccination, healthcare facilities should consider vaccinating unvaccinated healthcare personnel (HCP) born before 1957 who do not have laboratory evidence of measles immunity, laboratory confirmation of disease, or vaccination with 2 appropriately spaced doses of MMR vaccine.
However, during a local outbreak of measles, all healthcare personnel, including those born before 1957, are recommended to have 2 doses of MMR vaccine at the appropriate interval if they lack laboratory evidence of measles.
Healthcare facilities should check with their state or local health department’s immunization program for guidance. Access contact information here: www.immunize.org/coordinators.
CDC published a revised ACIP recommendation for IPV on August 6, 2009, to include a dose given at age 4 through 6 years (and at least 6 months after the preceding dose), regardless of the number of doses given before the fourth birthday. In general, you do not need to administer an additional IPV dose to older teens (or adults) who had already completed a routine 4-dose schedule of polio vaccination before their fourth birthday before the change was published in August 2009; however, if a dose given after the fourth birthday is needed for compliance with state requirements, you may want to check with your state immunization program or immunization registry manager to see what they accept/expect in this case. Contact information for state immunization managers can be found at www.immunize.org/coordinators.
The most current ACIP recommendations for Tdap can be accessed here at www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6903a5-H.pdf.
A listing of the recommendations follows:
Historically, HAV infection was highly endemic in institutions for people with developmental disabilities as a result of poor hand hygiene, close living conditions and diaper use. As fewer children have been institutionalized and as conditions in institutions have improved, the incidence and prevalence of HAV infection have decreased, although outbreaks can occur in these settings. All children with developmental disabilities should receive HepA vaccine according to U.S. routine vaccine recommendations, including catch up vaccination of all children through age 18 years.
As a strategy to further reduce the risk of hepatitis A outbreaks and reach adults in settings with a high proportion of people with risk factors for HAV infection, the current ACIP recommendations suggest considering HepA vaccination of residents and staff in facilities where hygiene is difficult to maintain, such as group homes for people with developmental disabilities and homeless shelters.
ACIP recommends that infants who have had rotavirus gastroenteritis before receiving the full series of rotavirus vaccination should still start or complete the schedule according to the age and interval recommendations because the initial rotavirus infection might provide only partial protection against subsequent rotavirus disease.
According to CDC, more than 80% of healthy adults who receive PPSV23 develop antibodies against the serotypes contained in the vaccine that persist for at least 5 years. Older adults and people with some chronic illnesses or immunodeficiency may not respond as well and their antibody levels may decline more quickly.
Overall, the vaccine is 60% to 70% effective in preventing invasive pneumococcal disease caused by serotypes in the vaccine. PPSV23 shows less effectiveness among immunocompromised people; however, because of their increased risk of invasive pneumococcal disease, CDC recommends PPSV23 for people in these groups who receive PCV15. There has not been consensus regarding the ability of PPSV23 to prevent non-bacteremic pneumococcal pneumonia; however, recent observational studies reported 21%–46% effectiveness against PPSV23-type pneumococcal pneumonia when PPSV23 was given less than 5 years before illness onset.
Unlike conjugate vaccines, PPSV23 vaccination has not been shown to decrease nasal carriage of pneumococcal bacteria among those vaccinated.
No. Pediarix is licensed for doses 1, 2, and 3 of the DTaP primary series through age 6 years.
