Page 151 - HA Convention 2015

Masterclasses

MC7.1 Advances in Infection 09:00 Theatre 1

Pneumococcal Vaccine in Children: Current Situation Tuesday, 19 May
Lau YL
Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong

In September 2009, 7-valent pneumococcal conjugate vaccine (PCV7) was included in the Hong Kong Childhood
Immunisation Programme (HKCIP). In October 2010, it was replaced by 10-valent pneumococcal conjugate vaccine (PCV10),
which was in turn replaced by 13-valent pneumococcal conjugate vaccine (PCV13) in December 2011.

The Centre for Health Protection (CHP) of the Department of Health (DH) conducts surveillance of invasive pneumococcal
disease (IPD) at several levels, including (1) a laboratory surveillance system covering all microbiology laboratories
in public and private hospitals in Hong Kong with the Public Health Laboratory Services Branch (PHLSB) of the CHP
centrally processing all pneumococcal isolates from sterile sites for serotyping, antimicrobial susceptibility testing and
characterisation; (2) from 2014, doctors were requested to report IPD cases in children under the age of 18 to the CHP,
which was extended by including IPD as one of the notifiable infectious diseases from January 2015; and (3) data related to
hospitalised IPD cases can be obtained from the Hospital Authority (HA). The data from different surveillance systems are
analysed to monitor the trend of IPD in Hong Kong, with particular focus on issues of serotype replacement, emergence of
serotype 3 and apparent increase in cases of empyema.

We observed significant changes in the disease burden of IPD for those aged under five after universal pneumococcal
vaccination in 2009. According to the PHLSB laboratory surveillance system, the overall incidence of IPD per 100,000
decreased from 8.8 before universal pneumococcal vaccination (from 2007 to 2008) to 6.5 after universal pneumococcal
vaccination (from 2010 to 2014). The decrease is even more substantial for those caused by serotypes contained in PCV7 (i.e. 4,
6B, 9V, 14, 18C, 19F and 23F) (from 4.6 to 1.5). On the other hand, the incidence of IPD caused by serotypes 3, 6A and 19A,
which are only contained in PCV13, increased from 2.5 to 3.7.

In 2014, we received 37 reports of IPD cases aged under 18. Pneumonia (35 of 37) was the commonest clinical presentation.
Serotypes 3 and 19A accounted for 20 and 9 of these cases respectively. Of these 29 cases caused by serotypes 3 and 19A,
11 had received at least three doses of PCV13. 22 cases were admitted to intensive care unit, with three fatal cases, two due
to serotype 3 and one serotype 19A.

In conclusion, serotype replacement in the IPD cases was observed and close monitoring is needed for serotype 3.

MC7.2 Advances in Infection 09:00 Theatre 1

Rotavirus Vaccine: Can This Prevent Hospital Admission? HOSPITAL AUTHORITY CONVENTION 2015
Nelson T
Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong

Rotavirus is the commonest cause of severe diarrhoea in young children under five years of age and remains a leading cause
of child mortality in this age group. Rotavirus is a double-stranded RNA virus with different strains serotyped according to
G and P structural proteins. A number of rotavirus vaccines have been licensed following studies demonstrating efficacy in
both developed and developing countries. Rotavirus vaccines are associated with a small risk of intussusception but the
documented health benefits of rotavirus vaccines far outweigh this risk. The World Health Organization (WHO) recommends
that rotavirus vaccines should be included in all national immunisation programmes. Countries that have followed WHO
advice have witnessed dramatic reductions in both rotavirus and all cause gastroenteritis admissions. In addition, these
vaccines may confer indirect protection to unvaccinated adults and older children as well as reduce nosocomial infections.
There are also unanticipated benefits of vaccination such as reduction in rotavirus-related convulsions. As of February 2015,
75 countries include the vaccine in their national immunisation programmes but relatively few countries in Asia have yet
done so. Analysis of Hospital Authority data for the period from 1 April 2000 to 31 March 2011 showed the cumulative risk
of admission by five years of age for rotavirus ranged from 1.4% to 4.5%, i.e. a Hong Kong child has a 1 in 69 to 1 in 22 risk
of being admitted to a public hospital with this vaccine preventable disease during the first five years of life. We now have a
strong evidence-base of the cost-effectiveness and real world impact of these vaccines – it is time for Hong Kong to lead in
Asia and incorporate rotavirus vaccine into the Childhood Immunisation Programme.

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