What are conjugated vaccines?
– Pathogens are surrounded by a polysaccharide capsule and are immunogenic
– Bacterial polysaccharides alone are poorly immunogenic in children
– When conjugated to carrier proteins (usually capsular or outer-membrane proteins), immune response is strengthened
• T-cell-dependent immunity to polysaccharides is triggered
• Strengthens immune memory
- good for mucosal immunity
What are live attenuated vaccines?
– Stronger mucosal immunity develops
– Not if immunocompromised
– Not if they have received blood products in the recent past (for some products, up to 11 months)
What are examples of conjugated vaccines?
- Meningococcal – Pneumococcal – Haemophilus Influenzae B – Hepatitis B – Influenza (injection) – Human papilloma virus (HPV) – Pertussis
Influenza
Yearly vaccine
Over 9 old: 1 dose
6 months to 9 years: 2 doses separated by at least 28 days
Influenza A and B
Quadrivalent (2 A/B per vaccine)
Virus changes from year-to-year
Antigenic drift
Antigenic shift
Very young, very old, chronically ill
Inactivated vaccine and live attenuated vaccine available (not presently being used)Meningococcal vaccines
• Two quadrivalent conjugate vaccines available
– Protect against meningococcal strains A/C/Y and W-135
– 75% of meningococcal infections in children 11 years and older involved these strains
– Recommended to start 2 dose series at 11-12 years of age
• Second dose at 16-18 years of age
• Two non-conjugate vaccines targeting serogroup B are available for children and young adults ages 10-25 years old
– Currently recommended at 16 years of age in the United States
Pneumococcal vaccine
• Strep pneumoniae is an important cause of respiratory tract disease (pneumonia, otitis media, and sinusitis), bacteremia and meningitis
– Particularly in children
– Becoming more and more resistant to antibiotics
• Conjugated 13-valent vaccine
• 2, 4, 6, and 12-15 months of age (healthy kids)
• Non-conjugate, 23-valent pneumococcal vaccine
– High risk patients
• Chronic lung disease
• Chronic cardiac, renal, and hepatic disease
• Diabetes
• Immunocompromising conditions such as sickle cell disease, HIV, and malignancy
– >24 months of age
Haemophilus Influenza Type B Vaccines
• Hib was once a leading cause of bacteremia, meningitis , cellulitis, and epiglottitis
• Hib capsular antigen is conjugated to either a tetanus or Neisseria meningitidis-derived carrier protein
• Given in 3-4 doses depending on brand
– 2,4,(6) and 12-15 months
– Alone or in one of the combination with DPT/IPV
– Number of doses needed depends on what age immunizations are started
Hepatitis Vaccines
• Hepatitis B
– A common cause of acute and chronic liver disease, hepatocellular carcinoma,
and death worldwide.
– Hepatitis B vaccine
• Recombinant DNA-produced hepatitis B surface antigen (HBsAg)
• Series is started a birth
– infection in newborns (usually asymptomatic) results in a chronic carrier state more than 90% of the time
– Birth (before discharge from hospital), 1-2 months, 6 months
• Hepatitis A
– Two single-antigen inactivated hepatitis A vaccines are available for use in children
• 12 months and 18-30 months of age
Diphtheria, Pertussis, and Tetanus Vaccines
• DTaP vaccine
– Diphtheria
• Acute membranous pharyngitis
• Can cause respiratory obstruction
• Now rare in the US
– whooping cough
• “100-day cough”, pneumonia, apnea, seizures, encephalopathy, high
mortality in young infants
• IT”S BACK
– Tetanus
• Severe muscle spasms provoked by a neurotoxin
• Can progress to respiratory failure
• Now rare in the US
• 2,4 and 6 months of age, 15-18 months of age, 4-6 years of age
• Tdap at 7 yrs of age, Td every 10 years (are 5 years of a dirty wound)
Polio Vaccine
• Vaccine has eliminated paralytic polio from the Western Hemisphere
• Only IPV in the US secondary to:
– Small risk of vaccine-associated paralytic poliomyelitis with live attenuated
vaccine
– Small risk of transmission of vaccine virus to unimmunized or immunocompromised household contacts with live virus
• 2,4,6-18 months, and 4-6 years
• There are still endemic areas for polio in the world
– OPV or live attenuated virus is still used
– Better mucosal immunity
Human Papillomavirus Vaccines
• Can cause genital warts, genital cancers (particularly cervical cancer), anal and head-and-neck cancers, and rarely lyryngeal papillomatosis (via vertical transmission during vaginal delivery)
• Two licensed vaccines, protect against the two most common HPV types
– Type 16 and type 18 are the most common (70% of cervical cancers)
– There are about 40 types of HPV that infect humans
• Recommended for boys and girls age 11-12 years
• A 9 valent vaccine is on the horizon
Measles-Mumps-Rubella and Varicella Vaccine
• Resurgence of measles occurred in 2014
• Overall, MMR have been largely eliminated from the US
• Varicella infection, varicella meningoencephalitis, and secondary complications of cellulitis and pneumonia have also declined
• 2 doses of both vaccines are given
– 12 months and 4-6 years old
• There is an MMRV vaccine
– Higher risk of febrile seizures
Rotavirus Vaccine
• Live virus
• Helps prevent acute diarrheal disease in healthy infants
• 2 dose or 3 dose schedule
– 2,4, (and 6) months of age
– First dose should not be administered after 14 weeks and 6 days of age
• Small risk of intussusception (1-5/100,000 doses)
T/F:
• MMR causes autism
• People with egg allergy cannot get the influenza vaccine
• The vaccines cause the disease
• Not getting immunizations decreases the overall lifetime risk for the child
all are false
What are the benefits of vaccinations?
– Individual immunity
• Provides long-term, sometimes lifelong protection against a disease
• Vaccines are developed for diseases that can kill and or permanently impair
– Herd immunity (community immunity)
• The concept that protection is provided to everyone in a community with high vaccination rates
When is the ‘go time’ for vaccinations?
first five years of life
What are inactivated/killed vaccines?
– Organism is carefully killed (thermally or chemically)
– Immunogenicity is retained
What is included in vaccines with subunit antigens and inactivated toxins (toxoids)?
the parts that best stimulate immune response
What vaccines tend to not last as long/need boosters?
conjugate
Why do we want to protect sickle cell pts from Pneumococcal infection?
- autosplenectomy: their spleen doesn’t work as well, so they are more susceptible to encapsulated infections
What are examples of nonconjugate inactivated or killed vaccines?
- Hepatitis A
– Polio (injection)
– Rabies
What are examples of live, attenuated vaccines?
- Measles-mumps-rubella – Varicella – Rotavirus – Influenza (nasal spray) – Zoster (shingles) for adults
What are examples of toxoid vaccines?
- tetanus
– diphtheria
