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CPD ACTIVITY
63
RET AIL PHARMA C Y • MA Y 2020
cause disease. The faecal-oral route
12
is the main mechanism of transmission.
However, rotavirus can survive on dry
inanimate surfaces for up to 60 days.
12
Typical symptoms and signs among
children with rotavirus infection include
vomiting, watery non-bloody diarrhoea,
and fever, which can last for up to eight
days. Mild symptoms last for shorter
duration. The contraindications and
13
adverse effects are reported in Table 1.
Pneumonia and the pneumococcal vaccine
There are two types of pneumococcal
vaccine:
• 13-valent pneumococcal conjugate
vaccine (13vPCV).
• 23-valent pneumococcal polysaccharide
vaccine (23vPPV).
The 13vPCV vaccine is composed of
protein-polysaccharide conjugates derived
from 13 serotypes. This replaced the
1
7vPCV vaccine, which was first introduced
for infants in 2000/2001.
4
13vPCV is recommended for the routine
immunisation of infants as per the NIP.
A total of three doses is administered to
healthy infants in their first year of life at
two months, four months and 12 months.
An extra dose is recommended at six
months for medically at-risk infants and
Aboriginal and Torres Strait Islander infants
in certain states and territories.
1
Streptococcus pneumoniae
,
an encapsulated bacterium, is a major
cause of pneumonia, bacteraemia and
meningitis worldwide. The incidence is
greatest in children aged over two years
and adults over 65, with associated
mortality rates ranging from about five to
20 per cent overall.
14
A Cochrane Review revealed invasive
pneumococcal disease (IPD) was
prevented in 80 per cent (P <0.0001) of
cases specifically for serotypes covered
with the 13vPCV. The overall efficacy for
IPD prevention caused by any serotype
was 58 per cent (P = 0.001). 13vPCV was
effective at reducing all-cause mortality by
11 per cent (P = 0.08). Analysis involving
HIV-1 positive children had similar
findings. Hence, routine vaccination has
15
had a statistically significant impact on
reducing the incidence of IPD, although
reductions in mortality wasn’t statistically
significant, likely due to the large
number of serotypes which precludes
widespread eradication.
However, children vaccinated with
13vPCV may also be protected from less
severe forms of the disease, such as acute
otitis media. In addition, there is good
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bacterium
Bordetella pertussis
. It is
transmitted via airborne droplets and is
highly infectious.
6
Pertussis affects nearly 24 million
children aged under five each year and
causes 160,000 deaths in this age group
worldwide. A higher incidence and
6,7
hospitalisation rate is observed in those
under six months old and those not fully
immunised, compared with older infants.
6,7
Mortality is high in this group, possibly
due to an immature immune system
and incomplete primary immunisation.
6,7
Australia has an accelerated primary
vaccination schedule at two, four and
six months to minimise the risks of early
disease. Pertussis can last up to three
1
months and is colloquially termed ‘the 100
day cough’. The typical symptoms and
6,7
time course are described in Figure 1.
Antibiotics effectively eliminate
B. pertussis
from the nasopharynx.
Therefore, treatment of established
disease minimises transmission to
susceptible contacts. In patients of any
5
age, antibiotic treatment is recommended
if the diagnosis of pertussis is made within
three weeks of cough or other symptom
onset. Patients should be advised to
avoid contact with others, especially
young children and infants, until antibiotic
therapy has been taken for at least five
days. After three weeks of cough or
5
other symptom onset, patients are rarely
infectious and antibiotic therapy is not
indicated. The antibiotics indicated for
pertussis are macrolides or trimethoprim
plus sulfamethoxazole.
8
Rotavirus and the live attenuated
oral vaccine
The rotavirus vaccine was introduced to
the NIP in 2006. It’s a live oral vaccine
4
containing sucrose. It’s recommended
9
to be given before injected vaccines as
the sucrose solution helps to mitigate
any pain caused by these injections.
10
It’s administered at two and four months of
age. Since the introduction of the rotavirus
vaccine, rotavirus-coded hospitalisations
of children aged under five years have
declined by 71 per cent (from 261 down to
75 per 100,000).
11
Rotavirus is still the leading cause of
viral gastroenteritis worldwide. It’s highly
contagious, with a high stool viral burden
and low infectious dose required to
Live attenuated vaccine
• Weakened form of the bacteria or virus that causes the disease.
• Creates long lasting immune response.
• Contra-indicated in immunosuppressed patients.
Inactivated vaccine
• Killed bacteria/virus.
• Immunity not long lasting and hence booster doses are required.
Subunit, recombinant, polysaccharide and conjugate vaccines
• Specific sections of the bacteria/virus that produces an immune response.
• Although strong immune response is evoked, booster doses are often needed later in life.
Toxoid vaccine
• Exotoxin produced by bacteria that causes the symptoms is heat/chemically treated.
• The treatment doesn’t affect immunogenicity.
Table 1.
Vaccine types available in Australia.
3
Figure 1.
The typical course of pertussis.
5
Time
Cough
1 - 2 weeks
3 - 4 weeks
1 - 12 weeks
Daily cough paroxysms
20
15
10
5
Catarrhal phase
inspiratory whoop, worsening at night
Cough,
Rhinorrhea
Paroxysmal phase
Cough paroxysms followed by
Post-tussive vomiting, Cyanosis,
Lymphocytosis, No fever
Convalescent phase