vaccines (malaria, travel etc) Flashcards
memory from adaptive immunity
Proliferation of 1st immune response (T and B cells)
Some into memory T. B cells
Shorter lag time when exposed to antigen A again
Activate memory T, B cells
HEIGHTENED STATE of reactivity
Shorter and stronger reaction
More/ higher
Better immunity
Live attenuated eg
- MMR
- Rotavirus
- Smallpox
- Chickenpox (varicella)
- Yellow fever
BCG
inactivated vac eg
Polio, hepA (food, water), rabies, flu (influenza)
jap encephalitis, influenza, tick-borne encephalitis
Subunit, conjugated vacc, eg
Hep B, pertussis, pneumococcus, HIB, influenza
typhoid (polysacc)
meningococcal
toxoid vacc eg
Diphtheria, tetanus
recombinant vacc eg
Hep B
HPV
live attenuated vaccine is _
○ Weakened virus after passing it through tissue culture multiple times
Replicates in body to stimulate a response
pros of live attenuated vacc
§ Activates killer T cells
§ 1,2 dose can provide lifelong immunity. Robust cell-mediated immunity
Like natural infection – stronger reaction
cons of live attenuated vacc
§ must be refrigerated.
§ Not suited for immunocompromised grps
□ Uncontrolled replication of virus
Clinical manifestation of disease
inactivated vacc is from _
Pathogen treated with heat or chemicals (killed)
Before introduction into body
inactivated vac pros
- Easy to store, transport
Low risk of causing infection
inactivated vac cons
- Elicit weaker immune response
- Booster
*Several doses
- Booster
Subunit
(Protein, polysacc, conjugated) vacc is __
One or more parts of pathogen (protein, polypeptide) isolated
Used to evoke immune response (weak)
subunit vacc pros
- Low risk of adverse reaction
Used in immune weakened systems
subunit vacc cons
- Difficult to manufacture
May need boosters
toxoid vacc is made from __
Toxins produced by pathogens instead of pathogen itself
Deactivated and used to produce immune response
- formaldehyde, temp, duration
toxoid vacc pros
- Unable to cause disease or to spread
Stable, easy to distribute, maintain immunity - anti-toxoid Ab produced, neutralise toxic effect
toxoid vacc cons
May need boosters to maintain immunity
or adjuvant
viral vector vacc
- Vector virus contains DNA spike protein
- Large
- Highly glycosylated transmem (of virus)
Vector virus are genetic makeup of diff viruses/ engineered viruses
- harmless, modified version of virus
recombinant vacc is made from
Vaccine produced by genetic engineering
May contain
* No actual virus (hep B, HPV)
* Modified strain of virus
- Live oral typhoid
recombinant: contain genes to encode specific antigen
precautions of live vaccine
○ Avoid in preg
§ Theoretical fetal infection
§ Live vaccines delayed until after delivery
○ Infancy <1 yr old
○ Severely immunocompromised pts
§ Hematologic, solid organs malignancies
§ Immunosuppressive meds, chemotherapy
§ HIV with CD4 < 200
- Small chance of uncontrolled replication – full-blown infection
○ Spaced 3-10 mnths apart from admin of Ab containing pdts
§ Ig, blood transfusion
§Circulating Ab may reduce the effectiveness of triggering an immune response
live vacc taken tgt
○ Another live vaccine SAME DAY/ within 28days
herd immunity
○ Enough pop immunised to:
§ Contain spread
§ Protect community
-Elderly, children, immunocompromised to qualify for vaccine
percentage for herd immunity
○ Percentage depends on how contagions disease is
§ Highly contagious = higher percentage needed
(measles high contagious: 83-84%)
- protect immunocompromised
primary dose
Single dose/ few doses (series)
Induce adequate immunity
booster dose
Ab conc wanes over time
Booster dose (additional dose) required to maintain protective lvl of Ab
childhood immunisations
12 vacc protects against 14 disease
3 are live
1) BCG
2) Hep B
3,4) dTAP & Tdap
5) IPV (polio)
6) Haemophilus influenzae type B
7) Pneumococcal conjugate (PCV10, 13)
8?) pneumococcal polysacc (PPSV23)
9) MMR
10) varicella
11) human papillomavirus 2/4
12) influenza
adult vacc schedule
Protects against 11 diseases
- means recc for adults that had not been vaccinated with these previously
1) influenza
2) pneumococcal conjugate PCV13
3) pneumococcal polysacc PPSV23
4) Tdap
5) HPV2/ 4 -
6) hep B -
7) MMR -
8) varicella -
effectiveness of vacc
1) Varies by vaccine
2) Other factors also affects
□ Site vaccine given
- Hep A/B at IM (deltoid) —- not gluteus
□ Pt age, immune status
-Less effective in older pts
□ Cold chain problems
- Recommended temp affects stability – quality of vaccine
Adverse effects (AE) of vacc
Mild, common:
□ Pain, redness, swelling at inj site
□ Headache
□ Myalgia
Uncommon
□ Fever, hematoma
Severe, rare:
□ Anaphylaxis, hypersensitivity (systemic)
risk of not giving vacc
□ Not giving pt a vaccine is also a risk
□ Exposes pt to disease, risk of mortality, morbidity and complications
CI, precaution of vaccine
Not to get vaccine at this time vs forever
□ Allergy to vaccine/ components
-Need look for substitutes
□ mod/ severe illness (>38*C)
□ Bleeding risk (pt on anti-coagulant, low PLT count)
- IM inj, bleeding in muscle risks
□ Pregnancy (No live)
□ Immunocompromised (No live)
Moderate/ severe illness (>38*C) precaution for vacc
No evidence to suggest that concurrent sickness will affect vaccine safety/ efficacy
◊ If pt is unwell, should defer until well to take vaccine
◊reduce any new symptoms for pt
◊ Delay vacc until recovered from acute illness
Simultaneous administration
§ Most vaccine administered simultaneously/ within same day
□ Without reducing efficacy/ incr AE
□ Prevent missed doses (adherence)
§ Live vaccine admin IM, SC spaced 28days apart
□ Reduce risk of Ab elicited from first vaccine to interfere with Ab of 2nd LIVE vaccine
no simultaneous for which 2 vaccs? vacc for
PCV, meningococcal conjugate vaccine in pt with functional or anatomical asplenia (no spleen)
□ 4 wk interval b. admin of 2 vaccines
-Avoid interference of meningococcal conjugate vaccine (with PCV)
missed dose
□ Dose given asap, continue course as if not interrupted
□no additional dose required
Resources to provide advice on preventing infections in travelers
○ Specific advice for travel destination
§ Routine vaccines before traveling
§ Recommended vaccination/ prophylaxis for certain countries (outbreak, endemic)
□ Yellow fever, malaria
medical considerations before int. travel
Pretravel consults: Preventive and educational interventions
§ 4-6 weeks before departure
§ Vaccines, prophylaxis takes time (gain suff conc// see ADR)
individual risk factor vary greatly
post travel advice
Indiv risk factors – risk assessment
- Medical history
- Medication
- Disabilities
- Allergies
- Immune status
- Immunizations
- Pregnancy
- Lactation
- Prior travel experience
- Specific itinerary
- Region (urban, rural)
- Season
- dates
- Activities
- Adventure travel, events
- More prone to food borne?
- How exposed to risk factors
- Type of accommodations
- Traveler’s risk tolerance
- CI to vaccine
- Financial challenges
- Expensive
- Time frame
*Freq of admin
Standard in-office interventions
1) admin of immunisation (update routune vacc: MMR, Tdap, pneumococcal, varicella, influenza)
2) routine travel vacc (hep A, typhoid, hep B)
3) special travel vacc (yellow fever, rabies, polio, meningococcal)
4) malaria chemoprophylaxis
5) traveler’s diarrhea (ORS, AB)
Focused education before trip
1) vector-borne disease
2) others (altitude, thrombosis, bloodborne, motor vehicle, resp, rabies)
3) medical kits
risk assessment for pretravel consult checklist
PMH
special considerations
immunisation hist
prior travel exp
itinerary
timing (duration, season, departure)
reason for travel
travel style (adventurous, food)
special activities
Post-travel advice
§ Continuous prophylaxis (malaria)
§ Self-assessment of any abnormal symptoms
§ Post travel incubation (as symptoms may take time to arise)
§ Visit doc, must remind to mention travel visit
- Travel vaccines available for common infections IMPORTANCE
○ Many travelers develop infections during travel
§ Avoided through proper vaccination
§ Risk avoidance
○ Travelers serve as conduits – spread disease across the globe
§ Covid, AB resistance
○ Less developed countries - higher rates of infection:
§ Saharan Africa, Southern Asia, Central, South America, Caribbean
Major routes:
§ Food, water borne: fecal-oral transmission (hand hygiene/ flies)
§ Insect vector borne
§ Transcutaneous (skin-skin)
§ Respiratory
§ Blood, body fluids (sexual/ contaminated needles)
Travel vaccines, routine vaccines updated recommended
some are compulsory in some countries:
routine: age app vacc
Meningococcus, poliomyelitis, yellow fever
resp (airborne, droplets)
influenza
pneumococcus
meningococcus
diphtheria, pertusis
hemophilus influenzae
MMR
chicken pox
BCG - TB
food and water transmission
hep A
typhoid
cholera
poliomyelitis
vector borne
yellow fever
jap encephalitis