By Stanley E. Grogg, DO, FACOP, FAAP; AOA Liaison Member to the CDC’s Advisory Committee on Immunization Practices (ACIP)

Each year, at the end of February or early March, the immunization schedules are published by the U.S. Centers for Disease Control and Prevention (CDC). Many times, a healthcare provider (HCP) needs more information than is found in the immunization schedule table. Most of the “specific” answers are found in the footnotes of the immunization schedules. This blog discusses many of the questions that HCP providers often ask about immunizations and is a two-part series about adult immunizations. Part 1 covers the COVID-19, Hemophilus B (HiB), Hepatitis A (HEPA), Hepatitis B Vaccine (HEPB) and Human Papillomavirus (HPV) and influenza vaccines. Part 2 will cover the remaining vaccines available in the United States.

COVID-19 Vaccines1

This will be added to the next year (2022) immunization schedules.2,3

Q: Are any of the COVID-19 vaccines recommended preferentially?2

A: No. The ACIP recommended the three COVID-19 vaccines—Moderna, Pfizer/BioNTech, and Johnson & Johnson (vaccine division, Janssen Pharmaceuticals)—be approved for Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) without a specific or preferential recommendation. The ACIP added a warning to the Janssen vaccine regarding blood clots developing especially in women between the ages of 18–49. The incidence of blood clots was less than one in 500,000 doses of the vaccine.3 The ACIP suggests obtaining the vaccine that is available in one’s particular area or state.4 Most likely by this publication, other companies will have additional FDA-EUA-approved vaccines, such as AstraZeneca and Novavax.

Q: Is there anyone over 18 years of age who should not get a COVID-19 Vaccine?13

A. Yes. According to the FDA, the Pfizer and Moderna vaccines should not be given to anyone who had a severe allergic reaction after a previous dose of the vaccine and/or had a severe allergic reaction to any ingredients of the vaccine. The Janssen vaccine should not be given to anyone who is allergic to any of the ingredients to the vaccine.13 Read further guidance for people receiving the COVID-19 vaccine.

Figure 1: Vaccine 2021 Schedule for Adults

Hemophilus B (HiB) Vaccine1 (Figure 1)

Q: Is the HiB ever recommended in adults?

A: Yes, although the HiB is usually a child’s vaccine, certain people should receive one dose of a HiB after 18 years of age, including adults with anatomical or functional asplenia, such as sickle cell disease. Patients who have had a stem cell transplant, should receive a three-dose series, four weeks apart starting 6–12 months after a successful transplant, regardless of HiB vaccination history.

Hepatitis A (HEPA) Vaccine1 (Figure 1)

Q: When should adults receive a HEPA vaccine?10

A: Until 2017, U.S. incidence rates of hepatitis A were driven by occasional outbreaks, often linked to viral contamination of imported food. Since 2017, large person-to-person outbreaks have been occurring across the United States, primarily among people who use drugs and people who are experiencing homelessness and unstable living arrangements. The following people10 should receive a HEPA vaccine:

  • Someone requesting the vaccine
  • Those with chronic liver disease or HIV infections
  • Men who have sex with men (MSM)
  • People with history of injection or non-injection illicit drug use
  • Homeless individuals
  • Those who work with hepatitis A virus in research labs or with nonhuman primates with possible hepatitis A virus infection
  • Those traveling in countries with high or intermediate endemic hepatitis A
  • People with close, personal contact with an international adoptee in the first 60 days of arrival from a country with high or intermediate endemic hepatitis A
  • Pregnant women, if at risk for infection or severe outcome from infection and in settings for exposure, including healthcare settings targeting services to injection or non-injection drug users or group homes and nonresidential day care facilities for developmentally disabled persons
Q: In the past, people with clotting factor disorders were at risk for hepatitis A due to their regular use of blood products. Why did ACIP decide to stop recommending routine vaccination of people with clotting factor disorders?10

A: People with clotting factor disorders were originally recommended to receive hepatitis A vaccine in 1996. At that time, the process used to make clotting factor supplements did not reliably inactivate hepatitis A viruses (HAV) and recipients of these products had an increased risk of HAV infection. Modern blood donor screening and virus reduction steps have drastically reduced that risk. In addition, more than 80% of people with clotting factor disorders now receive recombinant clotting factor concentrates that are sterilized and have no risk of HAV transmission. As a result of these factors, people with clotting factor disorders now have no greater risk of hepatitis A than the general population and are no longer recommended to receive HepA vaccine unless it is otherwise indicated.10

Hepatitis B Vaccine (HEPB)1 ( Figure 1)

Q: When should a person receive a HEPB vaccine?

A: Patients should receive a HEPB if they:

  • Request the vaccine
  • Are traveling to countries with high or intermediate endemic hepatitis B infections
  • Have a chronic liver disease, such as hepatitis C, cirrhosis, fatty liver disease, alcoholic liver disease, autoimmune hepatitis, alanine aminotransferase (ALT) or aspartate aminotransferase (AST) level greater than twice upper limit of normal.

Others recommended for HEPB include those with an HIV infection; those with potential sexual exposure risks, current or recent injection drug use, percutaneous or mucosal risk for exposure to blood; incarcerated persons; and women during pregnancy, if risk for infection or severe outcome from hepatitis B infection is present.

Q: A 25-year-old patient was inadvertently given a pediatric (0.5 mL) dose of Engerix-B. Can we just give her another pediatric dose or should she receive a repeat adult dose?

A: What you do depends on when the error is identified. If the error is discovered while the person is still in the office, you can administer the other “half” of the Engerix-B dose. If the error is discovered later, the dose should not be counted. The person should be recalled to the office and given a full age-appropriate 1.0 mL repeat dose. The same recommendation would apply if the error was with Recombivax HB.11

Human Papillomavirus (HPV) Vaccine1 (Figure 1)

Q: At what ages and what is the number of dosages of the HPV vaccine recommended?

A: Presently, only Gardasil 9 (9vHPV) by Merck is available in the United States.6 All people between 9–26 years of age should be vaccinated with the 9vHPV immunization to prevent certain cancers, such as cervical and oropharyngeal. If a person is 14 years of age or younger, a two-dose regimen may be utilized. At 15–45 years of age, a three-dose series is suggested. If a person 27–45 years of age wants a 9vHPV vaccine, shared clinical decision-making between the HCP and patient with discussions of the pros and cons of the HPV vaccine is indicated. If the patient has an immunocompromising condition, such as an HIV infection, a three-dose series is recommended from 45 years of age down to nine years of age, regardless of age at initial vaccination. If a patient has not had an HPV vaccination and is pregnant, 9vHPV is not recommended during the pregnancy; however, no intervention is needed if vaccinated while pregnant and pregnancy testing is not needed before vaccination.

Figure 2: Vaccine 2021 Schedule for Adults

Influenza Vaccine1 (Figure 2)

Q: Who should receive the annual influenza vaccine?

A: All persons aged six months or older should be vaccinated annually for influenza using an FDA-approved influenza vaccine with the appropriate dosage for the age of the patient who has no contraindications.

Q: Can a patient who has a history of Guillain-Barré syndrome receive an influenza vaccine? (Figure 2)

A: Guillain-Barré syndrome (GBS) is a rare disorder in which the body’s immune system damages nerve cells, causing muscle weakness and sometimes paralysis. While its cause is not fully understood, the syndrome often follows infection with a virus or bacteria. Each year in the United States, an estimated 3,000 to 6,000 people develop GBS. Most people fully recover from GBS, but some have permanent nerve damage. Studies suggest that it is more likely that a person will get GBS after getting the flu than after the flu vaccination. A history of GBS within 6 weeks after previous dose of influenza vaccine is a precaution for the flu vaccine. On the other hand, a patient with the history of GBS should be vaccinated with the flu immunization if the benefits outweigh the dangers for those at higher risk for severe complications from influenza.12

Q: Who can/cannot receive the influenza vaccine if they have an egg allergy?9

A: If a person states they have hives if eggs are ingested, then give one dose of any influenza vaccine appropriate for age and health status annually. If they have symptoms other than hives, such as angioedema or respiratory distress, they may receive a cell culture-based vaccine (ccIIV4, Flucelvax by Seqirus) with reduced egg products or the quadrivalent recombinant hemagglutinin influenza vaccine (RIV4, Flublok by Sanofi) without egg products.

Q: Are there special contraindications to consider when giving the live attenuated influenza vaccine LAIV (intranasal vaccine) by Astra-Zeneca?8

A: Yes, the LAIV is indicated for persons 2–49 years of age and no history of severe allergic reaction to a previous dose of any influenza vaccine. LAIV should not be used in patients who are immunocompromised due to medications, HIV infection, anatomic or functional asplenia; have close contact with or are caregivers of severely immunosuppressed persons who require a protected environment; during pregnancy; or if they have a cranial cerebral spinal fluid leak or oropharyngeal communications/cochlear implant. If a person received influenza antiviral medications oseltamivir or zanamivir within the previous 48 hours and peramivir within the previous five days, or baloxavir within the previous 17 days, LAIV is contraindicated. All vaccine providers should be familiar with the office emergency plan and should be certified in cardiopulmonary resuscitation.7 A previous severe allergic reaction to any influenza vaccine is a contraindication to future receipt of the vaccine.

Stay abreast of immunization recommendations with the CDC free immunization app for smartphones:5


  1. CDC’s Vaccine 2021 Schedules webpage: (Accessed 4/2/2021)
  2. Coronavirus vaccines: (Accessed 4/3/2021)
  3. Frequently Asked Questions about COVID-19 Vaccination: (Accessed 4/3/2021)
  4. ACIP recommendations for Janssen Vaccination: (Accessed 5/21/2021)
  5. CDC COVID-19 Vaccine Schedule APP
    1. Android Devices: (Accessed 4/9/2021)
    2. iOS Devices: (Accessed 4/9/2021)
  6. Only Gardasil 9 (9vHPV) human papillomatous is available in the US. (Accessed 4/3/2021)
  7. HCP needs to be ready to resuscitate patients if a reaction to a vaccination. (Accessed 4/3/2021)
  8. Use of LAIV: (Accessed 5/21/2021)
  9. Influenza vaccine and egg allergy. (Accessed 5/21/2021)
  10. Hepatitis A increased incidence in the US: (Accessed 6/9/2021)
  11. Accidental administration of Pediatric HepB Vaccine to an adult: (Accessed 6/9/2021)
  12. Guillain-Barre-Syndrome (GBS): (Accessed 6/9/2021)
  13. Who should not receive the COVID-19 Vaccine according to the FDA: (Accessed 6/9/2021)

Note: The CDC website is a public domain website, is not subject to copyright and may be freely used or reproduced without obtaining copyright permission. (Accessed 05/22/2021)


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