No. A number of studies have shown that HCP are not at significantly increased risk of HAV infection because of their occupation. However, if HCPs are going to work (or vacation) in a country with a high or intermediate endemic rate of HAV infection, they are at risk of HAV infection and should be vaccinated. The only occupational indications for routine HepA vaccination are work with non-human primates or live HAV in a laboratory setting.
Last reviewed:
June 25, 2023
In clinical trials and in postlicensure safety surveillance, the most common local adverse events within 7 days of receiving MenB were injection site pain, swelling or redness and the most common systemic symptoms were headache, fatigue and body aches. In general, these types of self-limited reactions are reported more frequently than with MenACWY vaccination.
Last reviewed:
November 15, 2024
There are various requirements for the use of vaccines after reconstitution. Some manufacturers’ package inserts require that the vaccine be used or discarded in varying time frames ranging from 24 hours after reconstitution to “immediately” after reconstitution. While the specific timeframes are simple to interpret, there can be some confusion as to what the requirement of “immediately” actually means.
CDC considers “immediately” to be the reasonable time it takes to prepare and transport the vaccine to the patient to be administered. This would include any limited documentation that may be related to this process. It is up to the judgment of a provider to determine if a vaccine has not been used in the appropriate time. Some manufacturers have indicated to providers that “immediately” can be up to 30 minutes. The definition of “immediately” varies from manufacturer to manufacturer. Some do not have the data to put forth a general timeframe as to what “immediately” means. CDC recommends that the provider contact the manufacturer if any question arises about whether or not a vaccine dose has been used in the appropriate timeframe.
Last reviewed:
July 26, 2023
Yes. This was a vaccine administration error since Twinrix, a combination hepatitis A/hepatitis B vaccine, is not licensed for people younger than 18. However, the hepatitis A and hepatitis B components can be counted as valid doses. The third dose of the Twinrix series should be given at least five months after the second dose.
Last reviewed:
July 15, 2023
Tdap vaccination for adolescents is recommended at age 11–12 years. A 10-year-old who is already up to date on diphtheria/tetanus/pertussis vaccines and gets a Tdap vaccine for any reason does not need to receive another Tdap at age 11–12 years.
Last reviewed:
March 31, 2022
Removing the protective cap increases the likelihood the septum or stopper could be punctured. The puncture may not be visible. It is important to ensure that the rubber seal on single-dose vials is not punctured because single-dose vials do not contain a preservative. Once the protective cap has been removed, the vaccine should be discarded at the end of the workday because it may not be possible to determine if the rubber seal has been punctured. For additional details, see CDC’s Vaccine Storage & Handling Toolkit at www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf.
Last reviewed:
December 28, 2022
Children age 6 months through 8 years should receive a second influenza vaccine dose 4 weeks or more after the first dose if they meet one of the following three criteria: 1) they are receiving influenza vaccine for the first time, or 2) they have not received a total of at least two doses of any seasonal influenza vaccine before July 1 of the current year, or 3) their vaccination history is unknown. The two previous doses need not have been received during the same season or consecutive seasons.
A child who is 8 years old and is recommended to receive two doses during the current season and turns 9 during the current season before receiving dose 2, should still receive dose 2.
Immunize.org’s handout titled “Guide for Determining the Number of Doses of Influenza Vaccine to Give to Children Age 6 Months Through 8 Years” provides additional guidance on this issue; it is available at www.immunize.org/catg.d/p3093.pdf.
Last reviewed:
August 11, 2024
ACIP recommends one dose of nirsevimab (Beyfortus, Sanofi) preventive antibody for all infants less than 8 months and 0 days of age who are born during or are entering their first RSV season.
ACIP also recommends one dose of nirsevimab for specific groups of infants and children age 8 through 19 months who are entering their second RSV season and at increased risk for severe RSV disease. These include the following:
Children 8 through 19 months at high risk and ineligible for palivizumab:
- American Indian or Alaska Native children entering their second RSV season. This is especially important for those who are in remote regions or in communities known to have increased rates of severe RSV disease in children.
Children age 8 through 19 months at high risk and eligible for palivizumab (Synagis, AstraZeneca):
- Children with chronic lung disease of prematurity who require medical support during the six months before the start of their second RSV season
- Children who are severely immunocompromised
- Children with evidence of severe cystic fibrosis (previous hospitalization for pulmonary exacerbation in the first year of life or abnormalities on chest imaging that persist when stable) or that have weight-for-length that is less than the 10th percentile
If nirsevimab is given to a child eligible for palivizumab, do not give palivizumab. If nirsevimab is unavailable, CDC recommends that palivizumab (a short-acting RSV monoclonal antibody) should be administered per AAP recommendations (see https://doi.org/10.1542/peds.2023-061803). Because palivizumab is effective for 30 days, if nirsevimab becomes available during the RSV season, aim to administer nirsevimab at the end of the 30-day period following the dose of palivizumab. Do not give palivizumab during the season after administering nirsevimab. In February 2024, AAP published updated guidance on prevention of RSV disease and the use of palivizumab when nirsevimab is unavailable: https://publications.aap.org/redbook/resources/25379/AAP-Recommendations-for-the-Prevention-of-RSV.
The full ACIP recommendation is available at www.cdc.gov/mmwr/volumes/72/wr/pdfs/mm7234a4-H.pdf.
Find further clinical considerations and information at CDC’s web page for healthcare providers on RSV immunization for infants and young children: www.cdc.gov/vaccines/vpd/rsv/hcp/child.html.
Last reviewed:
August 25, 2024
Yes. Evidence continues to demonstrate that COVID-19 vaccination is safe and effective during any stage of pregnancy; the benefits of vaccination clearly outweigh any known or potential risks of COVID-19 vaccination during pregnancy. The currently licensed or authorized COVID-19 vaccines are non-replicating vaccines and cannot cause infection in either the pregnant person or the fetus. No evidence exists of risk to the fetus from vaccinating pregnant people with non-replicating vaccines in general.
Data from the Vaccine Adverse Events Reporting System (VAERS), the V-safe surveillance system, and the V-safe pregnancy registry have not signaled any safety concerns for pregnant people who were vaccinated or their infants.
All people who are pregnant are recommended to receive a 2024–2025 Formula COVID-19 vaccine, as licensed or authorized by FDA, if they have not already received one.
Last reviewed:
November 16, 2024
No. All adults for whom pneumococcal vaccination is recommended due to age (50 or older) or an underlying condition (age 19 through 49) are now recommended to receive a pneumococcal conjugate vaccine. When PCV20 or PCV21 is given, no further pneumococcal vaccination is recommended. If PCV15 is given to an adult, PPSV23 is recommended one year later (minimum interval of 8 weeks). Prior recipients of PPSV23 alone may now receive PCV15, PCV20, or PCV21 at least 1 year after the dose of PPSV23.
Last reviewed:
November 13, 2024
It is not necessary to restart the MenACWY series. Give the person one dose of MenACWY vaccine now. This dose represents a delayed second dose in the 2-dose primary series recommended for people with HIV infection. The patient will subsequently need booster doses every 5 years.
Last reviewed:
November 15, 2024
Antibody titers to vaccine-preventable diseases decline during the 1-4 years after HCT, if the recipient is not revaccinated. HCT recipients are at increased risk for certain vaccine-preventable diseases, including those caused by encapsulated bacteria. In short, all HCT recipients should begin revaccination with inactivated vaccines 6 months after HCT. Three doses of pneumococcal conjugate vaccine (PCV) should be given 6 months following transplant followed by a dose of pneumococcal polysaccharide vaccine (PPSV) at least 8 weeks later. HCT recipients should receive 3 doses of Hib vaccine starting 6 to 12 months after successful transplant, regardless of vaccination history; doses should be administered at least 4 weeks apart. Immunocompetent people should receive MMR vaccine 24 months after transplant. For a complete discussion of the indications and schedule of vaccination, refer to the sub-section on recipients of HCT in the Altered Immunocompetence section of ACIP’s “General Best Practices Guidelines for Immunization” available at www.cdc.gov/vaccines/hcp/imz-best-practices/altered-immunocompetence.html.
Last reviewed:
August 29, 2022
Syncope (fainting) can occur before or after vaccination because of a vasovagal response to needles. Children should be seated or lying down during vaccination. Consider observing patients (with the patient seated or lying) for 15 minutes after vaccination to decrease the risk for injury should the patient faint. If syncope develops, the patient should be observed until the symptoms resolve. Immunize.org has simple, 1-page information sheets for patients (www.immunize.org/wp-content/uploads/catg.d/p4260a.pdf) and for healthcare professionals (www.immunize.org/wp-content/uploads/catg.d/p4260.pdf) concerning syncope and vaccination.
Last reviewed:
January 17, 2025
Most empty vaccine vials are not considered hazardous or pharmaceutical waste and do not require disposal in a biomedical waste container. Check and comply with your state requirements for disposal. Medical waste disposal requirements may vary from state to state because they are set by state environmental agencies. Contact your immunization program or state environmental agency for guidance to ensure your facility’s vaccine disposal procedures comply with state and federal regulations.
An exception to this principle is that an empty rotavirus vaccine dispensing tube or oral applicator is considered medical waste and should be disposed of in a medical waste container.
Last reviewed:
July 26, 2023
Decreased seroconversion rates might occur among preterm infants with birth weights less than 2,000 grams after administration of HepB at birth. However, by the chronological age of 1 month, all preterm infants, regardless of initial birth weight, are likely to respond as adequately as larger infants. Infants who weigh less than 2,000 grams born to HBsAg-positive mothers and mothers with unknown HBsAg status (if the mother’s HBsAg status cannot be determined within 12 hours of birth) must receive immunoprophylaxis with HepB and hepatitis B immune globulin (HBIG) within 12 hours of birth. The initial vaccine dose should not be counted toward completion of the hepatitis B series, and 3 additional doses of HepB should be administered, beginning when the infant is age 1 month. Infants weighing less than 2,000 grams born to HBsAg-negative mothers should receive the first dose of the HepB series at hospital discharge or at chronological age 1 month (even if weight is still less than 2,000 grams), whichever comes first.
Last reviewed:
January 17, 2025
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 for their risk of zoster before receiving Shingrix. Birth before 1980 is not sufficient proof of a history of primary varicella infection (chickenpox) for immunocompromised adults.
Vaccination with varicella vaccine to prevent chickenpox may be considered for a patient with well-controlled HIV (e.g., CD4+ T-lymphocyte percentage of at least 15% and a count of at least 200 cells per microliter) and no evidence of a history of varicella disease or vaccination. Vaccination may be considered for a patient who has a CD4 count of at least 200 cells per microliter but no information on percentage. Vaccination is contraindicated if a patient has laboratory information on the CD4 percentage and/or count and either measure falls below the recommended acceptable threshold for vaccination.
For other situations involving immunocompromised adults with no evidence of a history of varicella disease or vaccination, see detailed guidance provided by CDC at www.cdc.gov/shingles/vaccination/immunocompromised-adults.html#special-populations.
Last reviewed:
March 9, 2022
For routine vaccination, children without contraindications to MMR vaccine should receive 2 doses of MMR vaccine with the first dose at age 12–15 months old and the second dose at age 4–6 years old. The minimum interval is 28 days for dose 2. If you have an outbreak in your community or a child is traveling internationally, then consider using the minimum interval instead of waiting until age 4–6 years old for dose 2.
Last reviewed:
June 19, 2023
Commercially available laboratory tests for varicella antibody are usually based on a technique called EIA (enzyme immunoassay). Though these tests are sufficiently sensitive to detect antibody resulting from varicella zoster virus infection, they are generally not sensitive enough to detect vaccine-induced antibody. The more sensitive assays needed to detect vaccine-induced antibody are not widely available. This is why CDC does not recommend antibody testing after varicella vaccination.
Last reviewed:
May 16, 2023
No. In the past, outbreaks of hepatitis A occurred among children in child care centers, infecting employees of those centers, especially those caring for infants and toddlers. Following widespread adoption of early childhood vaccination against hepatitis A, outbreaks in child care centers are now rare.
Last reviewed:
June 25, 2023
It is prudent to allow the alcohol to evaporate, but it is unlikely that the small amount residual alcohol on the skin will affect the vaccine or increase the risk of an adverse reaction.
Last reviewed:
December 28, 2022
Twinrix is normally given as a 3-dose series on a schedule of 0, 1, and 6 months. However, if someone needs protection sooner (e.g., imminent foreign travel), you can give it as a 4-dose series at intervals of 0, 7, and 21–30 days, followed by a fourth (booster) dose at least 12 months after the first dose.
Last reviewed:
July 15, 2023
Children with SCID may be given inactivated vaccines (e.g., DTaP, Hib, hepatitis B, pneumococcal conjugate, hepatitis A, IPV, and injectable influenza). They should not be given live virus vaccines (e.g., live attenuated influenza, MMR, rotavirus, and varicella).
Last reviewed:
August 29, 2022
Yes, you can. Many of the conditions previously considered to be precautions to DTaP (e.g., temperature of 105°F or higher, collapse or shock-like state, persistent crying lasting 3 hours or longer, seizure with or without fever) did not apply to Tdap. These conditions are also no longer considered to be precautions to DTaP. This issue is addressed in the current ACIP statement, available at www.cdc.gov/mmwr/volumes/67/rr/pdfs/rr6702a1-H.pdf, page 3.
Last reviewed:
March 31, 2022
CDC publishes and routinely updates a comprehensive Vaccine Storage and Handling Toolkit covering topics such as vaccine storage units, temperature monitoring devices, and inventory management, vaccine transport and emergency vaccine storage and handling. The toolkit also contains troubleshooting guides to assist with vaccine storage unit issues or temperature excursions. This terrific resource, along with other vaccine storage and handling resources from CDC, is available online at www.cdc.gov/vaccines/hcp/storage-handling/.
In addition, Immunize.org maintains many free, downloadable materials at www.immunize.org/handouts/vaccine-storage-handling.asp.
Last reviewed:
July 26, 2023
Yes. A dose administered up to 4 days before the minimum interval for that dose may be counted as valid and does not need to be repeated.
Last reviewed:
March 2, 2024
Yes. Doses of FluMist administered in past seasons can be counted.
Last reviewed:
August 11, 2024
Infants and children 8 months through 19 months of age who meet one or more of the criteria listed below are recommended to receive 200 mg of nirsevimab (Beyfortus by Sanofi), administered as two 100-mg manufacturer-filled syringe (MFS) injections given at the same time at different injection sites) just before or during their second RSV season:
- Children with chronic lung disease of prematurity who required medical support (chronic corticosteroid therapy, diuretic therapy, or supplemental oxygen) any time during the 6-month period before the start of the second RSV season
- Children with severe immunocompromise
- Children with cystic fibrosis who have either 1) manifestations of severe lung disease (previous hospitalization for pulmonary exacerbation in the first year of life or abnormalities on chest imaging that persist when stable), or 2) weight-for-length less than the 10th percentile
- American Indian or Alaska Native (AI/AN) children
Nirsevimab is particularly important for AI/AN children who live in remote regions, where access to medical care may be challenging, or in areas where there are known high rates of severe disease among older infants and toddlers.
Last reviewed:
August 25, 2024
Yes. Adalimumab is a potent anti-inflammatory drug that blocks the activity of tumor necrosis factor (TNF). Adalimumab is considered immunosuppressive because serious infections have been reported in people taking the drug, including tuberculosis and infections caused by viruses, fungi, or bacteria. A person taking adalimumab or other drugs that affect TNF activity (such as infliximab [Remicade], certolizumab pegol [Cimzia], golimumab [Simponi], or etanercept [Enbrel]) should be considered to have immunosuppression and receive PCV20 or PCV21 alone or PCV15 followed by PPSV23. Clinicians can consider giving PPSV23 as soon as 8 weeks after PCV15 in this case, in order to accelerate protection against strains of pneumococcus unique to PPSV23.
Last reviewed:
November 13, 2024
As with all vaccines, a severe allergic reaction (for example, anaphylaxis) to a vaccine component or to a prior dose is a contraindication to further doses of that vaccine. A moderate or severe acute illness is a precaution; vaccination should be deferred until the person’s condition has improved. Because MenB is an inactivated vaccine it can be administered to persons who are immunosuppressed as a result of disease or medications; however, response to the vaccine might be less than optimal. Data on MenB vaccination during pregnancy is limited. Pregnancy a precaution to MenB vaccination, but MenB may be administered if, in the judgment of the clinician, the benefits outweigh any potential risks.
Last reviewed:
November 15, 2024
The answer is no. ACIP recommends only a single dose of nirsevimab for all infants younger than 8 months of age, administered during, or just before, RSV season. An infant who receives nirsevimab at the end of one season and who is younger than age 8 months at the beginning of the next season should not be given an additional dose.
Children who meet the high-risk criteria to receive a second dose of nirsevimab to protect them through their second RSV season should be at least 8 months of age (and younger than 20 months of age) at the time of administration of the second nirsevimab dose.
Last reviewed:
September 19, 2024
Valacyclovir, acyclovir, and famciclovir are antiviral medications that are active against herpesviruses, including varicella zoster virus. The risk of shingles risk is reduced during antiviral treatment. Since Shingrix is not a live virus vaccine, Shingrix may be administered while patients are taking antiviral medications if indicated.
A patient who is taking a prophylactic antiviral for a fixed period of time while their immune system recovers from HCT, should ideally initiate vaccination with Shingrix about 2 months prior to discontinuation of antiviral therapy.
Regardless of the duration of antiviral therapy after HCT, CDC recommends that autologous HCT recipients wait at least 3 months after transplant before initiating Shingrix vaccination. Allogenic HCT recipients should wait at least 6 months after transplantation. For additional details on timing after HCT, see www.cdc.gov/shingles/vaccination/immunocompromised-adults.html#clinical-guidance.
Last reviewed:
March 9, 2022
If you cannot verify a healthcare employee’s history of chickenpox, the employee should receive 2 doses of varicella vaccine at least 4 weeks apart. For details, refer to pages 16 and 26 of the CDC recommendations Prevention of Varicella at www.cdc.gov/mmwr/pdf/rr/rr5604.pdf.
Last reviewed:
May 16, 2023
A dose of MMR vaccine administered up to 4 days before the first birthday may be counted as valid. However, school entry requirements in some states may mandate administration on or after the first birthday. The 4-day “grace period” also may be applied to the 28-day minimum interval between two doses of MMR if the interval is inadvertently shorter than 28 days, although you should never plan to administer the second dose earlier than the 28-day minimum interval. This 4-day “grace period” does not apply to the strict 28-day minimum interval between two different live vaccines (e.g., MMR and varicella vaccines), if not administered at the same visit.
Last reviewed:
June 19, 2023
Although not at increased risk for hepatitis A virus (HAV) infection, people with chronic liver disease are at increased risk for fulminant hepatitis A, hospitalization, and death if they become infected with HAV. For this reason, HepA vaccination is recommended for them.
Last reviewed:
June 25, 2023
You should use separate alcohol wipes to clean the vial top and the patient’s skin.
Last reviewed:
December 28, 2022
Inactivated vaccines can be administered to people who take immunosuppressive drugs or who have a condition that causes them to be immunocompromised. The vaccines might not be as effective as they would be when given to a person with an intact immune system. If possible, the immunosuppressive drug should be discontinued for a month prior to vaccination, then allow the vaccine 2–3 weeks to generate an immune response before restarting the immunosuppressive treatment, but obviously, this is not always possible.
Determination of altered immunocompetence is important because incidence or severity of some vaccine-preventable diseases is greater in people with altered immunocompetence. As a result, certain vaccines (e.g., inactivated influenza vaccine and pneumococcal vaccines) are recommended specifically for people with altered immunocompetence.
More information can be found in ACIP’s “General Best Practices Guidelines for Immunization” available at www.cdc.gov/vaccines/hcp/imz-best-practices/altered-immunocompetence.html.
Last reviewed:
August 29, 2022
Yes. All adolescents should receive one dose of Tdap vaccine to protect them from pertussis, even if they have already received Td. It is important to do this right away (no minimal interval is required), especially if they are in contact with an infant younger than age 12 months, work in a healthcare setting where they have direct contact with patients, or live in a community where pertussis is occurring.
Last reviewed:
March 31, 2022
Few data are available on the effect of MenB vaccines on pregnancy. The manufacturers do not consider pregnancy to be a contraindication to use of MenB. GSK has established a Vaccination in Pregnancy registry. People who receive Bexsero during pregnancy may access information about the GSK Bexsero Pregnancy Registry here: https://pregnancyregistry.gsk.com/bexsero.html. Pfizer also maintains a Vaccination in Pregnancy registry for Trumenba, although specific contact details for this registry are not available. In general, vaccination against MenB should be deferred during pregnancy; however, MenB may be administered if, in the judgment of the clinician, the benefits outweigh any potential risk.
Last reviewed:
November 15, 2024
The CDC Storage and Handling Toolkit, available at www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf, contains information about recommended features to look for when selecting a temperature monitoring device or storage unit. If you store Vaccines for Children (VFC) or other federally-purchased vaccines, you may contact your state immunization manager or Vaccines for Children (VFC) coordinator for additional information on their recommendations or requirements. Contact information can be found here: www.immunize.org/coordinators.
Another option is to look for units that have the NSF/ANSI 456 certification. A refrigerator or freezer that is NSF-certified for vaccine storage means the units have been tested and certified to meet the NSF/American National Standards Institute (ANSI) 456 standards for construction and performance of vaccine refrigerators and freezers used in healthcare settings where vaccines are given. These standards were developed through a collaboration with NSF, CDC, healthcare providers, public health agencies, equipment manufacturers, and vaccine manufacturers, including experts from Immunize.org.
CDC does not require NSF-certified units for vaccine storage in the Vaccines for Children program or any other federal program. Not all storage units capable of reliably storing vaccines have this certification; however, all storage unit models with this certification have met design and performance standards to properly store vaccines under a range of normal clinic conditions.
Last reviewed:
July 26, 2023
Yes. If an HPV vaccine dose is administered at less than the recommended minimum interval, then the dose should be repeated. The repeat third dose should be repeated 5 months after the first dose or 12 weeks after the invalid third dose, whichever is later.
Last reviewed:
March 2, 2024
Twinrix is licensed as a 3-dose series for people age 18 years and older (minimum interval between dose 1 and dose 2 is 4 weeks; minimum interval between dose 2 and dose 3 is 5 months). It is also approved for use in an accelerated 4-dose schedule in adults, with doses given at 0, 7, and 21-30 days, followed by a booster dose at 12 months. There is no accelerated schedule for single antigen HepA or HepB vaccines, so the recommendations below presume the use of the Twinrix 3-dose routine schedule, with a minimum interval between dose 1 and dose 2 of 4 weeks.
If Twinrix is not available or if you choose not to use Twinrix to complete the hepatitis A (HepA) and hepatitis B (HepB) series, you should do the following:
- If 1 dose of Twinrix was given, complete the series with 2 adult doses of HepA and 2 adult doses of HepB.
- If 2 doses of Twinrix were given, complete the schedule with 1 adult dose of HepA and 1 adult dose of HepB.
Another way to consider this is as follows:
- A dose of Twinrix contains a standard adult dose of HepB and a pediatric dose of HepA. So, a dose of Twinrix can be substituted for any dose of the HepB series but not for any dose of the HepA series.
- Any combination of 3 doses of adult HepB or 3 doses of Twinrix is a complete series of HepB vaccine
- One dose of Twinrix and 2 doses of adult HepA is a complete series of HepA
- Two doses of Twinrix and 1 dose of adult HepA is a complete series of HepA
Last reviewed:
January 17, 2025
No. If there is no longer a CSF leak, pneumococcal conjugate vaccine is not recommended, unless there is another risk factor for invasive pneumococcal disease or an age-based indication.
Last reviewed:
November 13, 2024
The optimal timing for nirsevimab (Beyfortus, Sanofi) to be administered is shortly before the RSV season begins; however, nirsevimab may be administered to eligible infants and children who have not yet received a dose at any time during the season.
Nirsevimab should be administered to infants less than 8 months old and infants and children 8 through 19 months old during the months of October through March in most areas in the United States, unless otherwise advised by state or territorial public health authorities. Adjustment of timing due to RSV activity outside this typical timeframe is most likely to be necessary in tropical or sub-tropical climates and in Alaska.
Last reviewed:
August 25, 2024
Yes. COVID-19 vaccination with a 2024–2025 Formula vaccine is recommended for all people age 6 months or older, including those who are pregnant or lactating. Pregnant people are at increased risk of severe complications and death from COVID-19 compared to non-pregnant people of the same age. Those who contract COVID-19 during pregnancy also have almost twice the risk of stillbirth compared to those who do not contract COVID-19 during pregnancy. Studies have shown that antibodies produced after COVID-19 vaccination during pregnancy are transferred to the newborn, and COVID-19 vaccination of people who are pregnant reduces the risk of COVID-19 hospitalization in infants younger than 6 months. Pregnant people should receive any licensed or authorized updated 2024–2025 Formula COVID-19 vaccine during pregnancy, as licensed or authorized by FDA.
There is no recommendation from CDC for COVID-19 vaccination during every pregnancy; therefore, a person who is up to date on COVID-19 vaccination and becomes pregnant is not recommended to get an additional dose.
CDC, the American College of Obstetricians and Gynecologists (ACOG), and the Society for Maternal-Fetal Medicine (SMFM) all recommend vaccination, when indicated, of pregnant people at any stage of pregnancy.
For more details about COVID-19 vaccination during pregnancy, visit CDC’s webpage, “COVID-19 Vaccines while Pregnant or Breastfeeding”: www.cdc.gov/covid/vaccines/pregnant-or-breastfeeding.html.
Last reviewed:
November 16, 2024
Screening may be done with the hepatitis B surface antigen (HBsAg) test only. This blood test will tell whether a mother has current HBV infection that can be transmitted to the infant. Ordering a total antibody to hepatitis B core antigen (total anti-HBc) and/or anti-HBs are not useful when screening to prevent perinatal HBV infections and should not be included in screening during pregnancy for risk of perinatal HBV infection. Total anti-HBc will be positive in all HBsAg-positive people and anti-HBs is rarely positive in an HBsAg-positive person. Pregnant people who are found to be positive should be tested for HBV DNA to guide the use of maternal antiviral therapy during pregnancy for the prevention of perinatal HPV transmission (see MMWR 2018;67 [RR-1]:13).
An infant born to a mother for whom HBsAg screening test results during pregnancy are not available but other evidence suggesting maternal HBV infection exists (e.g., presence of HBV DNA, HBeAg-positive, or mother known to be chronically infected with HBV) should be managed as if born to an HBsAg-positive mother. The infant should receive both HepB and HBIG within 12 hours of birth. The mother should also be referred to their jurisdiction’s Perinatal Hepatitis B Prevention Program for case management to ensure that the infant receives timely prophylaxis and follow-up.
Last reviewed:
January 17, 2025
Last reviewed:
August 25, 2024
Last reviewed:
April 6, 2023
The risk for zoster and its severe morbidity and mortality is much greater for immunosuppressed people. A 2-dose series of Shingrix should be administered as soon as possible while the person’s immune system is intact. In cases such as this, depending upon the timing of chemotherapy initiation, you may wish to consider a shorter interval of at least 4 weeks (1 month) in order to complete the series as soon as possible.
Last reviewed:
March 9, 2022
Yes. However, if two parenteral or intranasal live vaccines (MMR, varicella, LAIV and/or yellow fever) are not administered on the same day, they should be separated by an interval of at least 28 days.
Last reviewed:
June 19, 2023
The two doses may be the same or different products.
Last reviewed:
August 11, 2024
No. Documented receipt of 2 doses of varicella vaccine supersedes results of subsequent serologic testing. Most commercially available tests for varicella antibody are not sensitive enough to detect vaccine-induced antibody, which is why CDC does not recommend post-vaccination testing. For more information, see page 24 of ACIP’s Immunization of Health-Care Personnel, available at www.cdc.gov/mmwr/pdf/rr/rr6007.pdf.
Last reviewed:
May 16, 2023
Yes. COVID-19 vaccination is recommended for people who are lactating.
Last reviewed:
November 16, 2024
Yes. Mothers who have received HepB should still be screened for HBsAg early in each pregnancy. Just because a pregnant person has been vaccinated does not mean they are HBsAg negative. Since postvaccination testing is not performed for most vaccinated people, the mother could have been vaccinated when already actively infected.
Last reviewed:
January 17, 2025
In published reports of three serologic surveys conducted among United States wastewater workers and appropriate comparison populations, no substantial or consistent increase in the prevalence of anti-HAV was identified among wastewater workers. No work-related instances of hepatitis A transmission have been reported among wastewater workers in the United States. In addition, in the United States, outbreaks of hepatitis A caused by flooding, which can carry raw sewage, have not been reported.
Last reviewed:
June 25, 2023
The stopper of a single-dose vial is often assumed to be sterile. However, not all vaccine manufacturers guarantee the tops of unused vials are sterile, and the manner in which the cover over the stopper is removed can potentially contaminate the stopper. Therefore, using friction and a sterile alcohol pad to swab the stopper may help to assure aseptic technique in preparing the single-dose vial prior to inserting a sterile syringe. Alcohol evaporates quickly and will dry while the needle is being prepared for insertion into the vial.
Last reviewed:
December 28, 2022
No. Twinrix contains 50% less hepatitis A antigen component than Havrix, GSK’s monovalent HepA vaccine [720 vs. 1440 EL.U.], so the patient would not receive the recommended dose of HepA vaccine antigen.
Last reviewed:
July 15, 2023
No. You should only use the (0.4% NaCl) diluent provided with the Dengvaxia vaccine vial. Contact your immunization program or the manufacturer for additional guidance.
Last reviewed:
January 17, 2025
Yes. There is no need to observe any minimum interval between doses of Td and Tdap except when administered as part of a catch-up primary series of tetanus vaccine.
Last reviewed:
March 31, 2022
Some American Indian or Alaska Native (AI/AN) children experience higher rates of severe RSV disease than the general population. A recent study found that the incidence of hospitalization due to RSV among some AI/AN children in their second year of life was four to ten times higher than that of similar-aged children in multiple study sites in the United States. Also, some AI/AN communities live in remote regions, making transportation of children with severe RSV to obtain medical care more challenging. Although the available data are limited and may not apply to all AI/AN children in all settings, ACIP recommends nirsevimab (Beyfortus, Sanofi) for AI/AN children entering their second RSV season.
Last reviewed:
August 25, 2024
No. Beta thalassemia minor is a hemoglobinopathy, but compared to sickle cell disease, these patients have less risk for functional asplenia, and therefore do not have a significantly increased risk of invasive pneumococcal disease.
Last reviewed:
November 13, 2024
Last reviewed:
August 25, 2024
A person who was on immunosuppressive chemotherapy in the past but is not expected to be immunocompromised again may follow routine recommendations for shingles vaccination at age 50 years or older. If the patient is age 19 or older and expected to require repeated exposure to immunosuppressive chemotherapy in the future, then it is preferable to vaccinate now while the patient’s immune system is more robust.
Last reviewed:
March 9, 2022
Yes. Adolescents and adults who started the HPV vaccine series prior to the 15th birthday and who are not immunocompromised are considered to be adequately vaccinated with just one additional dose of HPV vaccine.
Last reviewed:
March 2, 2024
