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COVID-19
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COMPLIMENTARY COVID-19 COURSES
CPD ACTIVITY
65
RET AIL PHARMA C Y • MA Y 2020
Figure 6.
Quarterly cases and annual rate of IMD, Australia, January 1, 2008 to December 31, 2018
by serogroup.
25
coryza or conjunctivitis. One or more
complications occurs in about 30 per
cent of measles cases. Diarrhoea is the
most common complication. Most deaths
are due to respiratory tract complications
or encephalitis.
17,18
In Australia, the overall vaccine
effectiveness is about 96 per cent
for one dose and 99 per cent for two
doses of measles-containing vaccine.
1
A Cochrane Review reported one-dose
vaccine effectiveness to be 95 per cent.
16
However, some studies, especially in
regions such as Asia and Africa, have
shown effectiveness to be lower in
one-dose recipients.
19
MMR vaccine schedule
Passively acquired, maternal anti-measles
virus IgG antibodies protect young infants
against measles in the first months of
life but can also interfere with vaccine
responses by neutralising vaccine virus.
Hence, the vaccine is not given in the
early months of life alongside Infanrix
and is first administered at 12 months.
However, a recent observational study that
monitored measles antibody titres from
nearly 200 infants in Canada may have an
impact on the scheduling of MMR vaccine
in the future. It revealed most infants are
susceptible to measles before 12 months
because of waning maternal antibody
protection. At three months of age, only
eight per cent of infants had protective
titres and by six months of age, no infants
did. Further research is required, but
20
it does reveal that infants aged under
12 months exposed to measles should
receive treatment with the MMR vaccine
or immunoglobulin. The vaccine should be
offered especially if travel is intended to an
area where there is a measles outbreak or
where measles has not been eliminated.
1
The contraindications and adverse effects
are reported in Table 1.
MMR vaccine and autism
Andrew Wakefield and colleagues
published a paper in 1998 in
The Lancet
:
‘Ileal-lymphoid-nodular hyperplasia,
non-specific colitis, and pervasive
developmental disorder in children’.
The case series revealed a link between
the MMR vaccine, bowel disease
and autism in 12 cases in children.
Following the publication, MMR vaccine
rates declined in the UK from 91 per cent
in 1997-98 to 80 per cent in 2003-04.
There was a similar drop in vaccination
rates in the US. Many epidemiological
21
studies followed with the aim of replicating
the data, but none showed a link. In 2004,
19
a journalist, Brian Deer, published a report
in
The Sunday Times
. The information he
had gathered uncovered the possibility
of research fraud, unethical treatment
of children, and Wakefield’s conflict of
interest through his involvement with a
lawsuit against manufacturers of the MMR
vaccine. This and other information was
22
later reviewed by the Genera Medical
Council in the UK and eventually led to the
removal of Wakefield from the UK medical
register in 2010. The notorious article
23
was retracted in the same year, 12 years
following its publication.
19
Interestingly, in Australia there
was no decline in vaccination rates.
They appeared to remain stable over
the late 1990s and into the first decade
of this century. Many put this down to
18
lack of media response to MMR vaccine
issues being played out in the UK and
the bipartisan support for the vaccination
program in Australia from the political
leaders, which was not the case in the
UK. However, individuals who missed out
18
on the MMR vaccine at 12 and 18 months
are now in their late adolescent/early
adulthood period of life. These individuals
notably travel and congregate with others
in large groups and hence are at high risk
of measles.
Meningococcal disease and the
MenACWY-TT vaccine
There are 13 serogroups of
Neisseria
meningitidis
and groups A, B, C, W,
Y and X cause most of the disease.
MenACWY-TT vaccine, (Nimenrix for
infants) contains four polysaccharide
components of the serotypes A, C, W
and Y, which are conjugated to a tetanus
toxoid protein. It was being funded in
various states for adolescents in 2017,
hence the drop-in meningitis rates as
shown in Figure 6. It was introduced in
2018 for infants. More than 97 per cent
TO PAGE 66
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Quarter and year of diagnosis
Number of notifications
Rate (per 100,000 population per year)
0
20
40
60
80
100
120
140
160
0
20
40
60
80
100
120
140
160
MenA
MenE
MenY
MenB
MenW
NG*
MenC
MenX
Annual ration for all IMD
*NG includes where meningococcal isolates could not be identified (‘not groupable’),
other isolates not grouped and where serogroup was not known.
1.3
1.2
1.0
1.1
1.0
0.6
0.7
0.8
1.0
1.5
1.1