PHAC reports 1-3 infant deaths from pertussis annually in
Canada. An equal number suffer irreparable brain damage from anoxic
spells. Not a massive amount, however
certainly beats the impacts of tetanus and diphtheria.
The rather dated PHAC information in the chart shows the
overall incidence of pertussis in Canada over decades, with recent incidences
of 2000-10000 cases annually.
Despite
tremendous gains in protecting infants, the current immunization strategy is
somewhat short and requires some difficult questions to be asked.
First and foremost is the need for primary immunization of
infants at a time where some parents are barraged with information on the risks
of immunization. Choices to avoid or
defer infant immunizations put the very children at the highest risk of severe
illness. The failure to immunize
amongst closely knit communities accentuates the risk within those communities
should illness get established.
Herd immunity has clearly been a benefit nationally. Secondary vaccine failure and the lack of
persistent protection may be setting the stage for a future dangerous storm. Breakthrough outbreaks are continuing to occur
and should be a warning sign. Adult pertussis is being more frequently diagnosed,
and likely increasing in incidence although surveillance is meager at
best.
Serious consideration needs to be given to the question of
whether the adult Td (tetanus diphtheria) booster should be replaced with the
TdaP (including ‘acellular’ pertussis vaccine) in routine adult immunization
programs. The current recommendations
are for a single dose of acellular pertussis after the preschool/kindergarten
vaccination, this is generally provided in Grades 7-9 (depending on province).
Of course, trying to get accurate costs on the cost differential
between the vaccines is challenging and guarded in business secrecy, however
the differential may well warrant the shift.
Recent outbreaks have punctuated the importance of both
unimmunized children and adults as vectors in dissemination of illness. As NACI meets this week, perhaps a topic for
consideration? While we are at it, it would
be nice to have NACI minutes and actions posted for increased transparency in
the decision processes NACI home site
Addendum: Please see the comment from NonStopGO. The posting is a reflection of the knowledge the issue is one for debate and several strategies are being promoted - however the discussion has not engaged the general public health community in a meaningful fashion. Using adult immunization is already being utilized for outbreak control in some settings. Thanks Nonstop
Addendum: Please see the comment from NonStopGO. The posting is a reflection of the knowledge the issue is one for debate and several strategies are being promoted - however the discussion has not engaged the general public health community in a meaningful fashion. Using adult immunization is already being utilized for outbreak control in some settings. Thanks Nonstop
Good post Dr. P... There are more recent developments in this, such as the CCDR posting (http://www.phac-aspc.gc.ca/ccdrw-rmtch/2011/ccdrw-rmtcs0111-eng.php) on the CID article by Healy et al http://cid.oxfordjournals.org/content/52/2/157.abstract
ReplyDeleteand the subsequent article in CID by Skowronski CID 2012:54 (1 February) ... I think the debate on this issue is still out and clearly requires detailed epidemiology on incidence rates to make the intervention effective.
Perhaps targetted cocooning??