New pertussis strain responsible for Australian epidemic: experts

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New pertussis strain responsible for Australian epidemic: experts

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21st Mar 2012

Danny Rose all articles by this author3 comments

New pertussis strain responsible for Australian epidemicA NEW dominant strain of the Bordetella pertussis bacterium may be driving Australia’s epidemic of infection, experts have warned.They say the new strain appears to fall outside of the protective range of the current narrow-spectrum vaccine.“The prolonged whooping cough epidemic in Australia that began during 2008 has been predominantly caused by the new genotype of B. pertussis,” said researcher Associate Professor Ruiting Lan from the UNSW School of Biotechnology and Biomolecular Sciences.“The genotype was responsible for 31% of cases in the 10 years before

the epidemic, and that’s now jumped to 84% – a nearly three-fold increase, indicating it has gained a selective advantage under the current vaccination regime.“We need to look at changes to the vaccine itself or increase the number of boosters.”Professor Lan's laboratory analysed 194 samples of B. pertussis collected between 2008 and 2010 in NSW, , South Australia and Western Australia.Their findings suggest while the current acellular vaccine and dose regimen remained effective against most forms of pertussis, the protection it offered against the emergent genotype “wanes more rapidly”.The new strain has also been detected in other countries and should be closely monitored, the researchers said.The acellular vaccine replaced a whole-cell vaccine from 1997 due to concerns about the latter’s side-effects. “The [whole cell vaccine] contained hundreds of antigens, which gave broad protection against many strains of B. pertussis," Professor Lan said.“The [acellular vaccine] contains only three to five antigens [and so] we need to ask what other strategies can be used to combat the epidemic, which is ongoing."There were 38,589 pertussis notifications during 2011, up from 4863 in 2007, though, as Professor Lan noted, recent improvements in diagnostic tests may be a factor in the rise.J Infect Dis 2012; 205:1220-24

Tags: Pertussis, vaccination, whooping cough, epidemic.

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Loud21st Mar 201211:21pm report

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So it wasn't all those 'evil' non vaccinated people spreading whooping cough after all eh? my question now is - is it a strain that has evolved due to mass vaccination? like what has happened to the high volume use of antibiotics?

Wron21st Mar 201211:30pm report

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I always thought we were conned when acellular vaccine came along at 4 times the price of whole-cell vaccine and 10% less efficacy. The paediatricians seemed to be leading the charge claiming fewer adverse reactions, though they never vaccinated any children. Out in GP-land, the number of reactions to pertussis vaccine always seemed pretty sparse.

salutarius22nd Mar 201210:13am report

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Some types of vaccination are obviously more important from a risk perspective than others; so there needs to be more of a balance in the vaccine debate rather than the current black and white perspective. Having said that, I would personally rather take my chances with a vaccine such as the one for tetanus than the disease. But "forced" vaccination is a polarizing problem and I believe the government should keep it's nose out of our medicine, because they usually screw up. Medical science is an ever changing and evolving field of endeavor; drugs and treatments are continually being replaced by better ones or abandoned because of unwanted side effects; no government agency could ever provide the flexibility to bring this message across to "consumers". So perhaps the government should leave it to doctors to make judgements and if the government wants to help, how about providing

grants to medical think tanks that are outside any government controls,

so doctors can get informed recommendations to the population. As far as Bordetella p. is concerned, it's not just a children's problem; it can play real havoc if you've got asthma.

YouJust nowFor

those who think that the problems with pertussis vaccines are all being

caused by a 'narrow spectrum' acellular vaccine, I would like to invite

you to look back on the research done by Professor Gordon T and

others in the 1980s and early 1990s in the UK. At that time, prior to the introduction of the acellular vaccine, it was being found that outbreaks were occurring with novel strains of b. pertussis and that b. parapertussis was also the cause of much morbidity - though it has never

been contained in the pertussis shot.

In addition, Dr found that whether an area had high, low or no vaccination against pertussis, it seemed to make no difference to the incidence of the disease nor could vaccination be used as a predictor for severity of illness once pertussis was contracted. The most important factor was socio-economic status and living conditions. Children who lived in poorer areas or who had more than 1 sibling were the most likely to contract whooping cough and be hospitalised as a result. Let's remember the lessons of history and not continually make the same mistakes.

Also, for those who claim that even though the vaccine may not prevent one from getting whooping cough it will make the illness milder if you do contract it - there doesn't seem to be evidence to back that assertion up. Where are the studies that demonstrate a decrease in morbidity in the vaccinated?

Let's start looking at why we are using this vaccine when it may have been responsible for the highest incidence per capita since before 1953 -

the year the pertussis vaccine was added to Australia's childhood vaccination schedule. Making policy decisions based on the best available science is usually the best way to go in cases such as this.

Meryl Dorey

Australian Vaccination Network.

Meryl Dorey,SpokespersonThe Australian Vaccination Network, Inc.Investigate before you vaccinateEditor,Living Wisdom MagazineFamily, Health, EnvironmentPO Box 177BANGALOW NSW 2479AUSTRALIAhttp://www.avn.org.auhttp://www.living-wisdom.comPhone: 02 6687 1699 FAX 02 6687 2032skype: ivmmagFreedom is not merely the opportunity to do as one pleases; neither is it merely the opportunity to choose between set alternatives. Freedom is, first of all, the chance to formulate the available choices, to argue over them -- and then, the opportunity to choose. - C. MillsThe authority of any governing institution must stop at its citizen's skin. - Gloria SteinemWe rely on the help and support of our members and subscribers to continue offering our services freely and without prejudice.Please consider helping us by subscribing to Living Wisdom and renewing your membership promptly if you are already an AVN member. Go to http://www.avn.org.au to subscribe or renew.We also sell books, videos and DVDs on vaccination and other health issues. Go to http://shop.avn.org.au/ for more details.PS - all of our subscriptions are currently on sale until December 24th. Our digital (online delivery) subscription is 50% off. Please check out the information at http://archive.constantcontact.com/fs082/1101800214009/archive/1108706073097.html