The most common types of serious complications caused by Hib include:

• Pneumonia (lung infection)
• Bacteremia (bloodstream infection)
• Meningitis (swelling of the lining of the brain)
• Epiglottitis (swelling of the throat)
• Cellulitis (skin infection)
• Infectious arthritis (swelling of the joints)

Meningitis is the most common form of invasive Hib disease, accounting for 50% to 65% of cases. Symptoms of meningitis include fever, decreased mental status, and stiff neck.

Mild infections caused by Hib include ear infections in younger children and bronchitis in adults.

If you think you may have symptoms for infections described above, talk with your healthcare provider.

• Hib spreads through close or lengthy contact with an infected person.
• The bacteria spreads through the air when an infected person coughs or sneezes which creates small respiratory droplets. Other people can get infected if they breathe in those droplets.
• People who aren't sick but have the bacteria in their nose or throat can also spread Hib.

Vaccination with Hib vaccine is the best way to protect you and your family against Hib disease.

The American Academy of Pediatrics (AAP) recommends infants receive their first Hib vaccine as early as 6 weeks of age.

• Dose 1: 6 weeks to 2 months of age
• Dose 2: 4 months of age
• Dose 3: 6 months of age (if needed; depends on the brand)
• Booster dose: 12-15 months of age

The Hib vaccine is safe and works very well in preventing Hib disease. Receiving all doses is 95% effective in preventing Hib disease.

Certain childhood vaccines (VAXELIS® and PedvaxHIB®) are preferred for American Indian and Alaskan Native infants to provide protection against Hib.

Hib vaccination may be recommended for certain adults with certain medical conditions such as not having a spleen (asplenia) or having a spleen that does not work well (functional asplenia, including sickle cell disease). Click here for more information.

If you have insurance:

• Talk to your doctor or check with your local pharmacy to see what vaccines they offer.
• Most health insurance plans cover the cost of recommended vaccines for children and adults.

If you are uninsured or underinsured:

• Programs are available to help cover the cost of vaccines.
• Children 18 years or younger may receive vaccines at no cost through the Vaccines for Children (VFC) Program if they are:
  • Eligible for or are enrolled in Medi-Cal
  • American Indian or Alaskan Native
  • Uninsured (do not have health insurance)
  • Underinsured (private health insurance does not cover the full cost of vaccines)
• Adults who are uninsured or underinsured may be able to get free or low-cost vaccines at clinics enrolled in the Vaccines for Adults (VFA) program. For more information on who is eligible, read VFA Eligibility Based on Insurance Status.

Locating Vaccine Clinics:

• A list of free and low-cost clinics in Los Angeles County.
• Interactive county map to locate free and low-cost vaccine clinics.
• Call 1-833-540-0473 (Public Health InfoLine) for a list of free or low-cost vaccine clinics. This includes Vaccines for Children (VFC) provider locations that serve Medi-Cal eligible children and uninsured or underinsured adults.

• Immunization Schedules: Birth to 6 Years Old | 7 to 18 Years Old | 19 Years and Older (AAP & AAFP)
• What You Need to Know: Hib Vaccine | Multi-Vaccine (Immunize.org)
• Haemophilus influenzae type b (Hib): Questions and Answers (Immunize.org)
• Hib (Haemophilus influenzae type B) (History of Vaccines)
• Paying for Vaccines (LAC DPH)

Haemophilus influenzae type B (Hib) can cause severe infections, particularly among infants. The most common types of diseases caused by typeable H. influenzae infections, including Hib, include:

• Pneumonia
• Bacteremia
• Meningitis
• Epiglottitis
• Septic arthritis
• Cellulitis
• Otitis media
• Purulent pericarditis

Less common infections include endocarditis and osteomyelitis.

Please contact the LAC DPH Vaccine-Preventable Disease Control Program to report a case or obtain any other technical assistance with specimen collection or completion of forms for Haemophilus influenzae.

Confirmed or suspected cases of invasive Haemophilus influenzae disease, any serotype, in children less than 5 years of age are to be reported within 1 working day from identification, by electronic transmission (including fax or email) or telephone to Los Angeles County Public Health Department per Title 17, California Code of Regulations, Section 2500.

• Weekdays Telephone: 8:30 am to 5:00 pm: Call 213-351-7800
• After Hours: Call 213-974-1234, option 8
• Email: vpdc@ph.lacounty.gov
• Fax Number: 213-351-2782

Non-invasive cases, including conjunctivitis and positive sputum culture without pneumonia or epiglottitis, and invasive cases confirmed not to be serotype B in patients 5 years old or older do not require public health reporting or investigation.

Although culture is the gold standard for confirming H. influenzae, real-time PCR is an accepted alternative.

The diagnosis of invasive disease is established by the growth of H. influenzae from a normally sterile body site (e.g., cerebrospinal fluid (CSF), blood, joint fluid, pleural fluid, pericardial fluid, peritoneal fluid, subcutaneous tissue fluid, placenta, bone, and amniotic fluid).

All H. influenzae isolates associated with invasive disease in children <5 years of age should be forwarded and serotyped at the Public Health Laboratory. Please call (562) 658-1460 for assistance.

Invasive Hib disease generally requires hospitalization. Antimicrobial therapy with an effective, third-generation cephalosporin (cefotaxime or ceftriaxone) should be started.

Post-exposure prophylaxis should be recommended as the risk of invasive Hib disease is increased among un- or under-immunized household contacts <5 years of age. Rifampin eradicates Hib from the pharynx in approximately 95% of carriers and decreases the risk of secondary invasive disease in exposed household contacts.

Indications and guidelines for chemoprophylaxis in different circumstances are described in the AAP Red Book and summarized in the CDPH Quicksheet for Invasive Haemophilus influenzae.

The American Academy of Pediatrics (AAP) recommends routine administration of a conjugate Hib vaccine series beginning at age 2 months. Infants 2 through 6 months of age should receive a primary series of one of the following vaccines:

• A 3-dose primary series of ActHIB®, HIBERIX, Pentacel®, or VAXELIS®
• A 2-dose primary series of PedvaxHIB®

The first dose can be administered as early as age 6 weeks.

Administer a booster dose of ActHIB®, HIBERIX, Pentacel®, or PedvaxHIB® at age 12 to 15 months.

Catch-up vaccination guidance for Hib vaccination for children under 5 years of age can be found here.

Young American Indian and Alaska Native children have a 31-fold higher incidence of invasive Hib disease than non-Native children. VAXELIS® and PedvaxHIB® are preferred for use in American Indian and Alaskan Native infants based on the Hib component because these vaccines provide protective antibody response after the first dose.

Hib vaccine is not recommended for most people 5 years of age or older unless they:

• Have certain medical conditions and are unvaccinated
• Receive a bone marrow transplant

Single antigen Hib vaccines (PedvaxHIB®, ActHIB®, and HIBERIX) can be given to older children and adults who need Hib vaccination.

Hib vaccines are highly effective in producing immunity to Hib bacteria. More than 95% of infants develop protective antibody levels after receiving a primary series of 2 or 3 doses of Hib vaccine.

*VAXELIS® and PedvaxHIB® are preferred over other Hib vaccines for American Indian and Alaska Native infants.
**The recommended age for dose 4 of Hib (PRP-T) (HIBERIX) is age 15 months, but to facilitate timely booster vaccination, it may be administered as early as age 12 months.
†The recommended age for dose 4 of DTaP-IPV/Hib (Pentacel®) is age 15 through 18 months, but it can be administered as early as 12 months, provided at least 6 months have elapsed since dose 3.
††The recommended minimum age for dose 3 of DTaP-IPV-Hib-HepB (VAXELIS®) is 24 weeks, the minimum age for completion of the hepatitis B vaccine series.
§VAXELIS® is not recommended for use as a booster dose. A different Hib-containing vaccine should be used for the booster dose.

• Check List: Managing Patients Suspected of Having Invasive Haemophilus Influenzae (H. Flu) (LAC DPH)
• Haemophilus influenzae, Invasive Disease (including Type B) B73 (LAC DPH)
• Invasive Haemophilus influenzae Quicksheet (CDPH)
• Immunization Schedules: Birth to 18 Years (AAP) | 19 Years and Older (AAFP) | CA Healthcare Personnel (CDPH)
• Vaccine Information Statements (Immunize.org): Hib (Haemophilus influenzae type B) | Multi-Vaccine (DTaP, Hib, Hepatitis B, Polio, PCV)
• Standing Orders for Administering Haemophilus influenzae type B Vaccine (Immunize.org): Adults | Children and Teens
• Haemophilus influenzae Infections (AAP)
• Los Angeles Health Alert Network (LAHAN) (LAC DPH)