4.1 Pneumococcal, Hep A, Hep B Vaccines

Pneumococcal Disease is caused by

infection due to Streptococcus pneumoniae ( > 90 strains or serotypes)

Many other causes of pneumonia

Common secondary infection after a primary viral infection such as influenza

Pneumoccocal Transmission

close, direct contact, respiratory droplets

Common local infections with pneumococcus

otitis media

sinusitis

bronchitis

pneumonia

Invasive pneumococcal disease (IPD) includes

meningitis, bacteremia, endocarditis, septic arthritis, osteomyelitis, peritonitis

IPD is most common in very young, elderly, and groups at high risk due to underlying conditions

Many people are asymptomatic carriers of S. pneumoniae

Antibiotic resistance increasing

2 different types of pneumococcal vaccine

1) Pneumococcal polysaccharide vaccine (PPSV) 23 valent

2) Pneumococcal conjugate vaccine PCV

• This vaccine has been improved over the years adding more strains to the mix

  • PCV13, then

  • PCV 15, then

  • PCV 20, then

  • PCV- 21 (approved in Canada July 2024) For adults 18 and older

Pneumococcal Vaccine Approval

Polysaccharide vaccine approved in 1983; conjugate vaccine approved in 2001 (added to routine childhood immunizations in 2005)

Pneumococcal Vaccine Efficacy

Pneumococcal conjugate (Pre-Prevnar 20) – in children < 5 years, 86% to 97% effective against IPD serotypes in the vaccine

Pneu-P-23 - > 80% effective against IPD among healthy young adults, and 50%-80% effective in elderly and high-risk groups (efficacy decreased in certain groups at high risk of pneumococcal infection, e.g., kidney failure, impaired immune response)

Pneumococcal Vaccine Preprations

Pneumococcal conjugate (SYNFLORIX®, 10 valent; Vaxneuvane , 15 valent; Prevnar®13, 13 valent; Prevnar®20, 20 valent, CAPVAXIVE® (21 valent))

0.5 mL IM

Pneumococcal polysaccharide 23-valent vaccine (PNEUMOVAX®23) 0.5 mL IM or SC

Prevnar 20 indications

Indicated for 6 weeks of age and older

Vaxneuvance Indications

Indicated for 6 weeks of age and older

Capvaxive Indications

Indicated for 18 years of age and older

Pneumovax Indications

Indicated for those 2 years of age and older

PCV 20 Indications for use in children (2 months to < 60 months)

For children without medical or environmental IPD risk factors, 12 to less than 24 months of age - 2 doses, at least 8 weeks apart. 24 to less than 60 months of age - 1 dose.

Children at high risk of IPD due to underlying medical condition should receive 4 dose schedule a 4-dose schedule at 2, 4, and 6 months followed by a dose at 12 to 15 months of age.

Children two years of age and older who are at increased risk of IPD and have never received any pneumococcal vaccination, should receive 1 dose of Pneu-C-20.

Pneumococcal Vaccine Recommendations for adults

Adult pneumococcal immunization programs in Canada should include at least one of Pneu-C-20 or Pneu-C-21.

One dose of either Pneu-C-20 or Pneu-C-21, regardless of pneumococcal vaccination history with Pneu-C-13, Pneu-C-15 or Pneu-P-23, should be given to:

• Adults 65 years of age and older

• Adults under 65 years of age at increased risk of IPD

• Medical risk factors and certain social, behavioural and environmental conditions can increase the risk of severe IPD illness in adults. A full list of risk conditions can be found within the NACI statement, along with specific recommendations for hematopoietic stem cell transplant recipienta

IPD High Risk factors

DM
HIV

chronic heart disease (CHD)

asthma

smokers

SUD

AUD

Pneumococcal Vaccine timing in vaccine naive

one dose PCV-20 or PCV21

Pneumococcal Vaccine timing with previous PCV13 dose

wait >= 1 year, then one does of PCV-20 or PCV21

Pneumococcal Vaccine timing with previou PPSV23 or PCV13/15+PPSV23

wait > 5 years, the one dose of PCV-20 or PCV21

Alberta Pharmacy Reimbursement for PCV20

Eligibility expanded Aug 1, 2025

Any adult 65 and older or;

18 and older who are at high risk for invasive pneumococcal disease (IPD) (common examples below-see AHS Prevnar-20 biological page for full list)

Chronic cardiac disease • Chronic liver disease • Chronic pulmonary disease • Diabetes • Biologic therapies • Behavioral and environmental risk factors • Alcohol use disorder • Use illicit drugs • Smoke/Vape

Hep A (HAV) type of virus, transmission and incubation period

RNA virus (Picornaviridae family)

fecal-oral route

incubation period of 28 days

HAV presentation and severity

Cases are infectious 2 weeks before the onset of symptoms until 1 week after onset of jaundice

Severity of illness increases with age (range from asymptomatic to mild illness to severe disabling disease lasting several months) -

• Children < 6 years commonly asymptomatic

• 25% of adult cases hospitalized

• Case fatality rate ~0.5%

• NOT associated with chronic hepatitis or carrier states

Does a natural Hep A infection confer immunity

yes, it confers immunity

Virus survivability and shed

Infants and children can shed virus for up to 6 months after infection.

Virus can survive in the environm ent for extended periods in harsh conditions

HAV Vaccine Approval

Vaccine introduced in 1996

HAV Vaccine Efficacy

Immunogenicity – protective concentrations of Ab after 1 dose is 95% to 100% (nearly 100% seroconvert after 2 doses)

Pre-exposure – 90% to 97% effective in preventing clinic HA illness

Post-exposure –protective efficacy ~80% if used within 1 week of exposure

HAV Vaccine type and preparations

inactivated; adsorbed to aluminum hydroxide adjuvant

AVAXIM®(adult) and AVAXIM®–Pediatric

HAVRIX®1440(adult), HAVRIX®720 Junior

TWINRIX® and TWINRIX® Junior (adult and pediatric; combined hepatitis A and hepatitis B)

VAQTA®

ViVAXIM® (combined typhoid and hepatitis A)

HAV Vaccine route and series

Route: IM

Series: 1 dose for primary immunization; booster dose 6 to 36 months later

HAV Vaccine Pre-Exposure Recommendations

persons 6 months of age and older at increased risk of infection or severe HA

Example: Travel

HAV Vaccine Post-Exposure Recommendations

offered to household and close contacts of proven or suspected cases of HA (e.g., group childcare centers, clients of infected food handlers)

Vaccine should preferably be given as soon as possible, and ideally within 14 days

Can be considered if > 14 days since last exposure (no data on outer limit of efficacy)

mmunoglobulin recommended for infants < 6 months of age, people for who vaccine is contraindicated and if HA vaccine is unavailable

HAV Provincial Funding for Pre-exposure

Criteria:

Chronic liver diease

Candidates or recipients of liver transplants

Residents of communities with high rates of hepatitis A infection

Households or close contact of children adopted from hepatitis A endemic countries

Lifestyle risks (MSM, illicit drug use)

Zookeepers, veterinarians and researchers who handle primates

Residents and staff of institutions for the developmentally challenge in which there is evidence of sustained hepatitis A transmission

Pre-Immunization serology for anti-HAV (IgG) is considered for what patients?

Individuals born prior to 1945

Individuals from an endemic country

People with history of hepatitis or jaundice that may have been caused by HA

Individuals diagnosed with hepatitis B and/or hepatitis C infection

Hepatitis B (HBV) type of virus and transmission

DNA virus (Hepadnaviridiae family)

Transmission: blood, semen, vaginal fluids

HBV Symptoms and Risks

Initial infection may be asymptomatic (adults 50%, children 90%)

Individuals who are able to successfully clear the virus in the first 6 months (acute infection) become immune

Risk of chronic infection varies inversely with age (10% of adults; highest risk in infants exposed during child-birth)

may develop liver disease or liver cancer

HBV Vaccine Approval

Vaccine available in 1982 in Canada; school-based programs started in 1987

HBV Vaccine Efficacy (Pre and Post exposure)

Pre-exposure – 95% to 100% effective in preventing chronic infection (3 doses of vaccine)

Post-exposure – highly effective in preventing HBV when given to exposed infants, within one week of percutaneous exposure or within 2 weeks of sexual exposure

Description of HBV Vaccine (what is it made of)

Purified HBsAg produced from the genetically engineered yeast strain

Antigen adsorbed onto aluminum hydroxide to boost response

HBV Vaccine Preparations Available

• PreHevbrio

• ENGERIX®-B (adult) and ENGERIX®-B –Pediatric

• RECOMBIVAX HB®(adult), RECOMBIVAX HB®-Pediatric, RECOMBIVAX HB®-Adult dialysis

• TWINRIX® and TWINRIX® Junior (adult and pediatric; combined hepatitis A and hepatitis B)

HBV Vaccine Route and Series

Route: IM

Series: varies

HBV Vaccine Recommendations for Use in infants and Children

routine immunization (age varies by jurisdiction) (not PreHevbrio as indicated only for >=18 years of age)

HBV Vaccine recommendations in adults

all susceptible people who wish to decrease their risk should be encouraged to be vaccinated (response rate decreases with age and overall health); publicly funded vaccine for those with increased risk of exposure or complications

Prehevbrio approval

Approved for use in Canada in late 2024 (have not seen availability or cost yet ~$65 per dose)

Prehevbrio dosing

1mL!!! At 0,1,6 months

Prehevbrio efficacy

Demonstrated noninferior protection in those >18 years of age and superior protection in those >45 years of age

Prehevbrio difference from other Hep B vaccines

Older vaccines target the HB S protein. Hevbrio targets the S, PreS1, and PreS2 proteins the PreS1 and PreS2 are considered more immunogenic.

Manufactured in mammalian cell line (Hamster ovary) vs Yeast culture

No data on whether interchangeable with older vaccines

Indications for Provincially Funded HBV Vaccine (Alberta)

3 doses 0,1,6 months

Unprotected adults born after 1981

Adults born before 1981 if at risk for Hep B exposure

• Health problems

• Type of work i.e. healthcare

• Lifestyle risk (MSM, IV drug use)

• Known contact with the infected individual

What combo vacicne is recommended to all travellers if not already vaccinated and why

Hep A + Hep B

Endemic in the populations of many developing countries

• Minor illness when infected as a child but higher chance of becoming a life-long carrier

• More significant illness if infected as an adult

3 types of Hepatitis B Antibodies/antigens

Anti-HBs

Anti-HBc

HBsAg

What is Anti-HBs

these are antibodies to the surface antigen of Hepatitis B which is in the vaccines

What is Anti-HBc

These are antibodies to the core protein within the virus

What is HBsAg

This is free Hepatitis B surface antigen

HBV Pre-immunization serology recommended for

individuals with HIV, chronic liver disease, high risk sexual practices, seeking STI treament, unportected sex with new partners, illicit drug users, non0immune adults from endemic areas

Serology of anti-HBs positive, HBsAg negative and anti-HBc negative is considered

considered immune

Serology of anti-HBs positive, HBsAg negative and anti-HBc positive (DOUBLE POSITIVE) is considered

immune

Serology of anti-HBs negative, HBsAg negative and anti-HBc negative (TRIPLE NEGATIVE) is considered

susceptible

After seroconversion how long is protection

protection appears to persist indefinitely

• Memory cells present, despite undetectable circulating antibody

Post-immunization serology recommended in specific circumstances • Timing is important as titers will fall naturally over time serology is usually performed within 12 weeks of final dose

What patient populations need HBV boosters?

Routine boosters not recommended for immunocompetent individuals

• In some select cases, booster doses may be recommended if anti-HBs titres fall below 10 IU/L

• time is important. Doing a test 5 years after the last dose that shows <10 does not mean a booster is necessary

Certain groups that are negative for anti-HBs after first series, may qualify for second vaccine series (or higher dose Ag vaccine)