Whooping Cough vaccine may need to change due to mutations

[BellyBelly]

Whooping cough vaccine may need to change, say researchers
By Danny Rose From: AAP February 10, 2010 4:15PM

THE bacteria that causes whooping cough in Australia has mutated, scientists have warned, eroding the protection provided by the vaccine now given to children.

Researchers from the University of New South Wales have identified significant changes in the two most common strains of the Bordetella pertussis bacteria, which they also traced back to events in the late 1990s.

Australian children were given a broad-acting "whole cell" vaccination against whooping cough up to 1997, but this was phased out over two years and replaced with a more targeted version. Concerns over potential side-effects were behind the change over to a vaccine with a narrower scope, but this now appears to have contributed to the promotion of resistant strains.

"A key issue is that the whole cell vaccine contained hundreds of antigens, which gave broad protection against many strains of pertussis," said Associate Professor Ruiting Lan of the UNSW School of Biotechnology and Biomolecular Sciences.

"But the (targeted) acellular vaccine contains only three to five antigens.

"Our findings suggest that the use of the acellular vaccine may be one factor contributing to these genetic changes."

The research team analysed more than 200 samples of the bacterium collected over the past 40 years in Australia, and these were compared with samples from Japan, Canada, USA and Finland.

They found while the vaccine now in use was effective against some of the strains circulating in Australia it may no longer protect against two strains, known as MT27 and MT70.

Dr Lan said more research was needed to confirm the results but health authorities may need to modify the vaccine to broaden the protection it offered, "or over time it could lose effectiveness as the organism evolves".

The discovery comes amid an increase in whooping cough cases in Australia, with several significant outbreaks seen last year in western Sydney.

Protection against whooping cough is contained in the range of childhood vaccinations which, in NSW, are usually given to infants at two, four and six months. Parents who opt out of this child vaccination process were thought to have contributed to the rise in cases, along with improved diagnosis, and the mutation discovery adds a third potential contributor.

One in 200 infants who contract whooping cough before they turn six months will die of the infection.

Read more: Whooping cough vaccine may need to change, say researchers | News.com.au

[BellyBelly]

Funny, everyone is so quick to blame the non-vacc'ers but now, oh yeah mutations could cause that too.

[Little Chicken]

The whole cell was phased out due to the number of side effects, one of the reasons they bought in the acellular. They may have to go back to the old one then.

[Cherished]

hi Kelly, let me know if I should start another thread with this question rather than hi-jacking yours dh and I don't want to give bubs any vaccinations but have recently been talking about Whooping Cough. I've been wondering if people can be carriers without knowing it, as in they aren't actually sick but can still pass on whooping cough to babies? Some people have suggested that we ask the grand parents to get a booster shot before seeing bubs but I don't feel 100% congruent with that because I am not a vaccination fan and would not like to be asked to get one myself... Some of the grandparents wont mind but there are 2 who I don't think would get a shot even if we asked (it's against their model of the world as it is ours) )and then they would be pretty unhappy not being able to see bubs for a month or so as we would want to give the little ones immune system some time to develop before getting passed around to everyone for a snuggle. So if whooping cough can't be passed on unless someone is actually sick with whooping cough than I wouldn't be so worried, I mean I know it's out there but I have personally never come across someone who either has or has had it so I may not even bother asking anyone to get a booster. I hope all that makes sense.

[Little Chicken]

A lot of adults don't know they have it because it manifests more like a cold with a bad cough in them. It is usually only babies and small children that get the characteristic whoop cough. To be safe I would say anyone who has a cough or cold shouldn't go near bub.

[Cherished]

hmmm thanks muminalice, that doesn't really answer my question though can someone be a carrier without having symptoms (even a cold)? I wish I could think of an example but my brain is mush lol. But there are heaps of diseases out there where people can give it to someone without getting it themselves kwim?

[RhiChiChi]

hmmm thanks muminalice, that doesn't really answer my question though can someone be a carrier without having symptoms (even a cold)? I wish I could think of an example but my brain is mush lol. But there are heaps of diseases out there where people can give it to someone without getting it themselves kwim?

Hun, I don't know for sure BUT my gf was immunised against Rubella and when she was pg with her DS she was a CARRIER but not affected by it nor was her son. (she had the rash etc...) So, I would say that it is a high potential that you could be a carrier but not present with symptoms or present with lesser ones (cough but not whoop cough) like muminalice said.

[skybie]

hun majority of bubbies get whopping cough from their parents. if u dnt want bub to have the vaccine then perhaps look into getting u and DH done, im pretty sure its still free.

lol i love how non vaccers are to blame for the increase in whooping cough cases....really??!! hmmmm

[Schmickers]

the contagious period with whooping cough begins with the onset of cough and cold symptoms. By the time the characteristic cough starts, most people have been contagious for some time.

The good news, though, is that whooping cough usually requires an extended period of exposure to spread - it is usually spread between members of the same household, who have had hours in close contact.