Vaccine preventable diseases Flashcards
What is the NHS vaccination schedule for babies under 1 year old?
8 weeks:
- 6-in-1 vaccine
- Rotavirus vaccine
- MenB
12 weeks:
- 6-in-1 vaccine (2nd dose)
- Pneumococcal vaccine
- Rotavirus vaccine (2nd dose)
16 weeks:
- 6-in-1 vaccine (3rd dose)
- MenB (2nd dose)
What is the NHS vaccination schedule for
Children aged 1 to 15
What is the NHS vaccination schedule for adults and pregnant women?
What is the 6-in-1 vaccine?
-diphtheria
-hepatitis B
-Hib (Haemophilus Influenza type b)
-polio
-tetanus
-whooping cough (pertussis)
What are the features of Diphtheria?
- Early signs: mild fever, swollen neck glands, anorexia, malaise, cough
- 2-3 days: membrane of dead cells forms in the throat, tonsils, larynx or nose
- May narrow or occlude the airway leading to respiratory distress
What are the severe symptoms of Diphtheria?
*Toxin can travel through the bloodstream causing extensive organ damage, neurological and heart complications
*Death occurs in 5-10% of cases
*Milder infection can still occur in people who are partially vaccinated or were vaccinated a long time ago
What is Diptheria?
What is the mode of transmission of Diphtheria?
*Infectious respiratory disease caused by toxigenic strains of bacteria Corynebacterium diphtheriae or Corynebacterium ulcerans
*Transmitted via airborne droplets
*Bacteria infect the throat and sometimes the skin
*Incubation period from 2-7 days
*Patients with untreated disease may be infectious for up to four weeks
*Affects people of all ages - most serious in young infants and the elderly
Symptoms of Tetanus (Generalised)
Initially: muscle stiffness of the jaw (“Lockjaw”) in 50% of cases
Followed by: neck stiffness, difficulty swallowing, stiffness of stomach muscles, muscle spasms, sweating and fever
Complications Include;
* Fractures
* Hypertension
* Laryngospasm
* Pulmonary embolism
* Aspiration
* Death
Describe Neonatal Tetanus
*More frequent in developing countries
*Infant born without protective passive immunity
*Infection of the umbilical cord stump
*High fatality rate without therapy
What is the cause of Tetanus?
Describe the incubation period.
*Caused by the bacterium Clostridium tetani
*Non-communicable therefore vaccination is required for protection (no herd immunity)
*Bacteria form spores that can survive in the environment for years
*Tetanus may occur if a wound or cut is infected by soil or manure
*Incubation period 4-21 days
*Affects people of all ages
*People who recover from tetanus do not have natural immunity, therefore, need to be immunised
Symptoms of Pertussis
- Initially: cold-like symptoms -runny nose, watery eyes, sneezing, fever and a mild cough
- Followed by: a gradually worsening cough, which develops to paroxysms of coughing followed by a characteristic whoop
Describe Pertussis
*Disease of the respiratory tract caused by Bordatella pertussis
*Spread easily from person to person in droplets produced by coughing or sneezing
*Most dangerous in children under 1 year, most severe in young infants
*Incubation period 6-20 days with a range of 4 - 21 days
*Infectious from 6 days after exposure to 3 weeks after onset of cough
*Duration of illness can be 2-3 months
Describe Paralytic Polio
- Less than 1% of all polio infections result in flaccid paralysis
- Paralysis develops within 1-10 days after prodromal illness and progresses for 2-3 days
- The use of one or both arms or legs may be lost and breathing may not be possible without
the help of a respirator.
The degree of recovery varies from person to person
Describe the Polio virus
*Three types - I, II, & III
*Virus enters via the mouth
*Replicates in the pharynx and GI tract
*Invades local lymph tissue
*Enters blood stream and may infect cells of the central nervous system causing aseptic meningitis
*More rarely replicates in and destroys the motor neurones which activate the muscles (~1:100 infections)
Describe the dynamics of Poliomyelitis
*Transmitted through contact with the faeces or pharyngeal secretions of an infected person
*Incubation period: ranges from 3 – 21 days
*Infectiousness: not precise but transmission is possible as long as the virus is excreted
*Virus can be excreted for up to six weeks in the faeces and two weeks in saliva
*Most infectious immediately before and 1-2 weeks after the onset of paralytic disease
Describe the Polio vaccine
*Until Oct 2004, the live polio vaccine, given by mouth was used in the UK
*Very effective and stimulates an immune response in the blood and gut
*Very rarely (1 in a million) vaccine virus reverts back to the wild type causing Vaccine Associated Paralytic Polio (VAPP)
*Cases of VAPP have been reported in recipients of OPV and in contact of the recipients
*OPV replaced by IPV
Describe Haemophilus influenzae type b (Hib)
disease
*Caused by infection with Haemophilus influenzae bacteria
*Transmission occurs from coughing, sneezing, and close contact with an infected person.
*Healthy individuals can carry Hib bacteria in their nose and throat without symptoms
*Incubation period less than 10 days
*Most common presentation of invasive Hib is meningitis,
frequently accompanied by bacteraemia (60%)
*15% of cases present with epiglottitis
Describe rotavirus transmission
-Most common cause of diarrhoea in children aged ≤5 years worldwide
-Highly infectious: only 10-00 virus particles are needed for infection
-Transmission mainly through the faecal-oral route
-Contaminated food/water
-Contact with contaminated objects or surfaces
-Can live for hours on their hands and get spread by human contact
-May remain viable in the environment for months if not disinfected
-Sometimes through respiratory droplets: by sneezing and coughing
-Children can spread rotaviruses both before and after they become sick with
diarrhoea = increased risk in daycare facilities
-Contagiousness period 8 days (>30 days if immunocompromised)
What are the symptoms of rotavirus?
*Sudden onset abdominal pain & vomiting - usually lasts 24-48 hours
*Profuse watery diarrhoea - lasting 3 to 8 days (median 6 days)
*Mild to Severe dehydration – if untreated can result in death
*Fever
*Adults and older children can also become infected – mild symptoms, often asymptomatic
*DIAGNOSIS: often based on symptoms and physical examination, but can
test stools for rotavirus antigen
*TREATMENT: supportive care, rehydration (preferably orally), may need
hospital admission for IV fluids.
Describe the Rotavirus burden
Globally:
* Nearly every child will have rotavirus gastroenteritis by 5 years of age
* 1 in 5 will visit an outpatient clinic
* 1 in 60 will be hospitalised
* 1 in 293 will die due to the disease (600,000 deaths annually)
In England and Wales, in children <5 years of age:
* 90-133,000 GP consultations (25% of GP consultations for gastroenteritis)
* 37,000 NHS Direct calls (27% of NHS direct calls for gastroenteritis)
* 30,000 A&E attendances
* 14,000 hospital admissions (45% of gastroenteritis admissions)
The estimated annual cost of £14.8 million in E&W
What are the early symptoms of Measles?
*Early symptoms include:
- runny nose
- cough
- red and watery eyes and
- small white spots inside the cheeks (Koplik’s spots)
What are the early symptoms of Measles?
*Early symptoms include:
- runny nose
- cough
- red and watery eyes and
- small white spots inside the cheeks (Koplik’s spots)
What are the later symptoms of Measles?
*Followed by:
- A slightly raised rash develops, spreading from
the face and upper neck to the body and then to the hands and feet over a period of three days
- Rash lasts 5-6 days
- Loss of appetite and loose stools
Describe Measles
*Extremely contagious viral illness caused by Morbillivirus
*Most common in 1-4-year-olds
*Spread by contact with nose and throat secretions and in airborne droplets released when an infected person sneezes or coughs
*Transmission period is from the beginning of the first symptoms to 4 days after the appearance of the rash
*Incubation period ranges from 7 to 18 days
Describe complications of Measles
*Complications occur in approximately 30% of reported cases
- Infants, adults and immunocompromised are at the highest risk of severe complications
*Severe diarrhoea may be a problem, especially for infants, causing dehydration (8 per 100 cases)
*Pneumonia affects 1-6 per 100 cases and is the commonest cause of death
*Otits media (7-9 per 100 cases), convulsions (1 in 200)
*Encephalitis may also develop (1 per 1000 cases)
*Subacute sclerosing panencephalitis (SSPE) is rare but fatal. complication of measles infection (1 per 25,000 all cases; 1 per 8000 <2yrs)
*Death (1 in 5,000 cases in UK)
Describe Influenza
*An acute infection of the respiratory tract caused by type A, B or C influenza virus
*Influenza A usually causes more severe illness than B
*Transmitted by aerosol, droplets or direct contact with respiratory secretions of an infected person
*Highly infectious with an incubation period of 1-3 days
*There are seasonal and annual variations in the incidence
*Most cases occur within 6-8 week winter period (peak Dec-March)
Describe Flu epidemiology
- Flu activity usually between September to March (weeks 37 and 15)
- Impact of flu varies from year to year
- Moderate levels of influenza activity were seen in the 2014/15 season
- ICU/HDU admissions in 2014/15 were higher than seen in the previous few seasons
Symptoms of influenza
Sudden onset of:
-fever
-chills
-headache
-myalgia
-extreme fatigue
-dry cough, sore throat and stuffy nose
In healthy individuals: unpleasant illness but recover 2-7 days
Complications of flu
In more vulnerable individuals can lead to complications of:
-secondary bronchitis
-bacterial pneumonia
-otitis media (in children)
In severe cases, may lead to:
-meningitis
-encephalitis
-meningoencephalitis
-death (at least 3000-4000 each winter)
Evolution of UK flu vaccination programme
Influenza Vaccines
How are LAIV administered?
LAIV is sprayed into the nose using a simple syringe-like device that delivers a 0.1-mL volume of a large-particle aerosol into each nostril for a total volume of 0.2 mL
Varicella (Chickenpox) & Zoster (Shingles)
*Acute highly infectious disease caused by the varicella-zoster virus
*Transmitted by personal contact, droplet spread, contact with infected articles
*Most common in children under 10 years
*Seasonal with peak March-May
SARS-CoV-2
an enveloped, single- and +ve-stranded RNA virus
* genome comprises 29,891 nucleotides which encode 12 putative ORFs responsible for the synthesis of viral structural and non-structural proteins: envelope (E), membrane (M), nucleocapsid (N), and spike (S).
Spike protein subdomains:
* S1 contains the receptor-binding domain (RBD):
ACE2 binding
* S2 contains the fusion machinery:
enabling virus entry
most vaccine candidates target the S protein
different vaccines for SARS-CoV-2
List diseases that would need vaccines.
HIV
Malaria**
Better TB…*
Coronavirus**
RSV**
Group B streptococcus**
Group A streptococcus*
Staphylococcus aureus*
CMV
