CNS Infections- Prevention & Vaccines Flashcards
(41 cards)
Community-acquired meningitis:
Before the introduction of the measles and mumps vaccine, viral meningitis/meningoencephalitis was more common than bacterial meningitis. Even after the widespread (and successful) use of the measles and mumps vaccine, ___________ remains more common than _________. In fact the measles and mumps vaccine has made the most significant reduction in the number of cases of meningitis compared to the case rate/100,000 persons in the pre-vaccine era.
viral meningtis (not mumps or meales etiology)
bacterial meningitis
Community-acquired meningitis:
For bacterial meningitis, _________ accountED (past tense) for majority of community-acquired cases and _________ was responsible for most of cases involving children. After a conjugated ____ vaccine was in common usage, ________ became the leading cause of community-acquired meningitis.
children
Community-acquired meningitis:
Recently a conjugated ________ was developed for infants and children.
pneumococcal vaccine
Community-acquired meningitis:
After common usage of the Hib conjugated and pneumococcal conjugated vaccines (TODAY), _______ account for the majority of community-acquired cases of bacterial meningits and __________ is now responsible for most cases, then _______, lastly _______. But the case rate for meningococcal meningitis has not changed over time.
adults
Neisseria meningitidis
Streptococcus pneumoniae
Hib
Vaccines exist for CNS diseases caused by
- N. meningitidis
- S. pneumoniae
- H. influenzae, type b
- polio
- rabies
- botulism
- tetanus
- measles
- mumps
Immunization with polysaccharide conjugate vaccines (T dependent antigen) helps by:
- decrease carriage rate.
- decrease incidence of disease (is capable of class switching)
- IS recommended for children
T dependent antigen vaccine for S. pneumoniae
-7/13 valent conjugated vaccine (PCV-7/13)
PCV=polysaccharide conjugate vaccine
-Recommended for all children up to 5-y-o-age –FDA has approved its use to prevent pneumococcal otitis media, meningitis, and bacteremia
T dependent antigen vaccine for N. meningitidis
2 vaccines- give names and age groups
-Quadrivalent (groups A, C, Y, and W-135) polysaccharide diphtheria toxoid (CRM197) conjugate vaccine
- Menactra (MCV4; Sanofi-Pasteur) for all persons aged 11→ 18-y-o-age AND for persons aged 2→55 years at increased risk for meningococcal disease.
(TEENS or YOUNG/ADULTS AT RISK) - Menveo (Novartis Pharmaceuticals, Inc) in people 11 to 55-y-o-age.
(NORMAL TEENS AND ADULTS)
N. meningitides group B vaccines (2 of them)
- 4CMenB (Bexsero; composed of 3 recombinant proteins)
2. Trumenba (composed of 2 recombinant proteins).
Immunization with polysaccharide
(Type II, T-independent antigen) vaccines:
- decrease incidence of disease
- NO decrease in carriage rate due to NO class switching
- is NOT recommended for children
Type II T-independent antigen vaccine for S. pneumoniae
23 valent (pnu-immune Pnuemovax)
Type II T-independent antigen vaccine for N. meningitidis: (only 1)
- Tetravalent/quadrivalent polysaccharide vaccine for Groups A, C, Y, W-135
1. Menomune (MPSV4)
Type II T-independent antigen vaccine for H. influenzae, type b (Hib)
Pure polysaccharide vaccine
compared to T dependent ag vaccine for Hib which is a Conjugated vaccine
Immunoglobulin (Ig) preps exist for:
- Rabies
- Tetanus
- Botulism
Post-exposure prophylaxis to prevent rabies:
Protocol: Rabies vaccine, IG, wound care, tetanus immunization
If carriage of H. influenzae, type b and/or N. meningitidis is detected by nasopharyngeal cultures:
1 . eliminating the immune carrier state by chemoprophylaxis of both vaccinated and non-vaccinated individuals.
2. Treat to prevent spread in families and closed populations like daycares and college campuses
If carriage of H. influenzae, type b and/or N. meningitidis is detected by nasopharyngeal cultures TREAT with:
Ciprofloxacin, ceftriaxone, rifampin, or azithromycin
unless fluoroquinolone-resistant N. meningitidis is detected in the area, if so, then do not administer ciprofloxacin
Description of Inactivated (killed) Polio Vaccine (IPV)
Other names: Salk vaccine or IPOL
1st version of polio vaccine
- trivalent
- prepared by formalin inactivation of wt (wild type) virus, grown in primate tissue culture.
- Primary series is at least 4 inoculations over a 1→ 2 years
- High efficacy
(> 90%, seroconversion/immunity)
Polio-
Enhanced potency vaccine (e-IPV):
- more potent than original IPV
- results in increased seroconversion rates
- is the only IPV vaccine approved in US
i. e., IPV = e-IPV
Advantages of Polio vaccine
e-IPV
Safe/no risk for unvaccinated persons, e.g., the immunocompromised.
Limitations to Polio vaccine
- Given parentally (i.e., injected) – more expensive than Oral polio vaccine (OPV) administration.
- Does not generate high sIgA responses but rather a serum IgG response. This response is still efficacious since if a vaccinated person is exposed to WT virus, the WT virus must first disseminate in blood and lymphatics to reach the CNS and serum anti-polio-IgG helps clear virus from these sites.
- Boosters are needed. In developing countries, a 4th booster may be required.
- Only protects those actually vaccinated. So religious/philosophical groups not participating in vaccine program can/do occasionally become infected in local outbreaks → the spread of wild-type (wt) virus.
Oral polio vaccine (OPV)
aka Sabin
- trivalent vaccine.
- live attenuated virus which replicates in oropharynx and intestinal tract but cannot infect neuronal cells, less transimisable than wt virus.
- OPV has significant advantages over e-IPV
Limitations to Oral Polio Vaccine (OPV)
- Puts other unvaccinated family members and contacts at risk, may spread to immunocompromised persons (vaccine is live)
- During viral replication in vaccinated children, the attenuated virus mutates back to the virulent/wt virus , but only causes extremely rare cases of vaccine-associated paralytic polio/poliomyelitis (VAPP) in the US (8→10 cases/year).
- Vaccine-derived poliovirus can circulate in the population, (cVDPV).
In 1997, ACIP recommended use of e-IPV for first 2 doses (2, 6 months) and OPV forlast 2 doses (6 → 12 m, 12 → 16 m). This will prevent any back mutations from causing clinical manifestations (back mutations of OPV will still occur).
HOWEVER- In June 1999, ACIP and AAP recommended ______________
4 doses e-IPV (IPOL) ONLY to eliminate any chance of vaccine-associated paralytic polio and in doing so, assure parents and thus obtain better vaccination compliance.
