Vaccine refusal linked to higher risk of measles and pertussis


Vaccine exemption is associated with an increased risk of measles and pertussis, as evidenced by a recent US study.

To assess if vaccine refusal, delay or exemption was linked to outbreaks of measles and pertussis in the US, researchers looked for studies published between January 2000 (post-measles elimination era) and November 2015 for the measles cohort and from January 1977 to November 2015 for the pertussis cohort. [JAMA 2016;315:1149-1158]

There were 18 published studies on measles comprising 1,416 cases in individuals ranging from age 2 weeks to 84 years (178 cases in individuals <12 months). Of these, 56.8 percent (n=804) occurred in individuals with no history of measles vaccination, while 14.1 percent (n=199) occurred in vaccinated individuals. Of 970 cases with detailed vaccination information, 574 cases were in individuals who were age-eligible for the measles vaccine yet did not receive one, with 70.6 percent (n=405) of them unvaccinated due to nonmedical reasons.

Among 32 pertussis outbreaks comprising 10,609 cases in individuals aged between 10 days and 87 years, 24-45 percent of the five largest outbreaks (Arizona in 1988, California in 2010 and 2014, Washington and Oregon in 2012) involved unvaccinated individuals. In eight of 12 reports with data on reasons for non- or undervaccination (fewer than recommended doses), 59 to 93 percent were unvaccinated due to vaccine refusal.

There were reports of pertussis epidemics in communities with high vaccination rates, an occurrence study authors attributed to a decline in immunity. However, there was still an association between vaccine refusal and pertussis risk in some communities, they said.

The authors believe that enforcement of vaccine mandates, be it at a school- or state-level, as well as increasing the difficulty to acquire exemption are crucial to raising vaccination rates in the community. However, they also highlighted the importance of acknowledging reasons for vaccine hesitancy among parents, such as perception on risk of vaccine-preventable diseases and safety of routine vaccination.

This study builds up on previous data that showed an association between vaccine refusal and risk of varicella, pneumococcal disease, measles, and pertussis.

What is the Deadliest of All Vaccines?


The standard DTP or DPT (diphtheria, pertussis (whooping cough) and tetanus) vaccine is acknowledged to be the deadliest of all vaccines, causing more disability, illness and the highest risks, even exceeding MMR (measles, mumps and rubella).
 
 
The U.S. Department of Health and Human Services set up the National Vaccine Injury Compensation Program (NVICP) in 1988 to compensate individuals and families of individuals injured by covered childhood vaccines. The VICP itself was adopted in response to a the pertussis portion of the DTP vaccine.
Since 1988, the program has been funded by an excise tax on every purchased dose of a covered vaccine. To win an award, a claimant must show a causal connection; if medical records show a child has one of several listed adverse effects soon after vaccination. The burden of proof is the civil-law preponderance-of-the-evidence standard, in other words a showing that causation was more likely than not.As of May 2013, the VICP has paid out $2.7 billion for cases involving injury amongst all vaccines.It obliges drug companies that produce vaccines to contribute to the program by paying an excise tax on each dose of vaccine, based on potential risk.Although the taxes raised by the vaccine tax go into a “trust fund,” this trust fund, like most government trust funds, is on paper only. According to the most recent report on the fund, November 2012, the balance in the fund is nearly $3.5 billion.

Epidemiologists Admit Pertussis (Whooping Cough) Is Spreading And Vaccines Are The CauseWhooping cough, or pertussis, is spreading across the entire US at rates at least twice as high as those recorded in 2011 and epidemiologists and health officials are even admitting that the vaccines may be the cause.

The cause could very well be due to multiple loads of toxins delivered through the DTP vaccine which include, (but not limited to): formaldehyde, aluminum hydroxide, aluminum phosphate, thimerosal, and polysorbate 80. That means that every DTP vaccine contains carcinogenic, neurotoxic, immunotoxic and sterility agents just like many of this year’s flu vaccines. These chemicals then bioaccumulate in the child with each successive vaccine, further introducing an additional load of toxins with each injection.

Dangerous new strains of whooping cough bacteria are now evading Australia’s vaccine against the disease and entrenching a four-year epidemic that could soon spread overseas, Sydney scientists have found in research that raises questions about the national vaccine program.

The dangerous new strains of whooping cough bacteria were reported in March 2012. The vaccine, researchers said, was responsible. The reason for this is because, while whooping cough is primarily attributed toBordetella pertussis infection, it is also caused by another closely related pathogen called B. parapertussis, which the vaccine does NOT protect against. Two years earlier, scientists at Penn State had already reported that the pertussis vaccine significantly enhanced the colonization of B. parapertussis, thereby promoting vaccine-resistant whooping cough outbreaks.

According to the authors:

“… [V]accination led to a 40-fold enhancement of B. parapertussis colonization in the lungs of mice. Though the mechanism behind this increased colonization was not specifically elucidated, it is speculated to involve specific immune responses skewed or dampened by the acellular vaccine, including cytokine and antibody production during infection. Despite this vaccine being hugely effective against B. pertussis, which was once the primary childhood killer, these data suggest that the vaccine may be contributing to the observed rise in whooping cough incidence over the last decade by promoting B. parapertussis infection.”
Pertussis whooping cough is a cyclical disease with natural increases that tend to occur every 4-5 years, no matter how high the vaccination rate is in a population using DTP or Tdap vaccines on a widespread basis. Whole cell DTP vaccines used in the U.S. from the 1950’s until the late 1990’s were estimated to be 63 to 94 percent effective and studies showed that vaccine-acquired immunity fell to about 40 percent after seven years.
In the study cited above, the researchers noted the vaccine’s effectiveness was only 41 percent among 2- to 7-year-olds and a dismal 24 percent among those aged 8-12The fact that many vaccines are ineffective is becoming increasingly apparent. Merck has recently been slapped with two separate class action lawsuits contending they lied about the effectiveness of the mumps vaccine in their combination MMR shot, and fabricated efficacy studies to maintain the illusion for the past two decades that the vaccine is highly protective.
History of Adverse Events Associated With The DTP Vaccine The whole-cell pertussis component is associated with a range of adverse events, including serious neurological consequences. Concerns about the safety of whole-cell pertussis vaccine date back to the 30s and 40s. By the 1950s, concern about potential adverse events led some researchers to begin searching for a more refined, acellular version of pertussis vaccine with less reactogenicity.Fertility has been declining rapidly since the 1950s in all countries of the world and the start of the change coincided with the introduction of the first mass vaccination programs. For instance, in the UK in 1947, a mass DPT vaccine campaign was initiated and in 1958, the first polio and diphtheria vaccines were brought in on a mass scale for all people under 15 years old.

In the early to mid-1970s, the safety of whole-cell pertussis came under increasing scrutiny both in the U.S. and abroad. Newly heightened concerns were in part related to reports published
in Great Britain and Germany linking whole-cell pertussis vaccine to long term neurologic effects.

In 1975, in response to the deaths of two infants within 24 hours after DTP vaccination, Japanese health authorities temporarily suspended the routine use of pertussis vaccine in infants, and soon after recommended that vaccination against pertussis start instead at age two years.

In Britain, while health authorities continued to recommend routine DTP immunization for infants, the public became increasingly wary of potential adverse effects, and many parents chose not to immunize their children.

From 1978 through 1981, a total of nine product liability lawsuits were filed against DTP manufacturers in the U.S.. For the single year 1982, however, 17 DTP lawsuits were filed; and by 1986, the number of pertussis productliability suits filed during the year reached an all-time high of 225. During a six-month period in 1984, in response to the growing liability crisis, two of the three manufacturers distributing DTP in the U.S. market B Wyeth and Connaught B dropped out.

In 1997, the DTP vaccine was taxed at the highest rate per dose – $4.56 – compared with $0.29 for polio and $0.06 for DT (without pertussis). Only the MMR vaccine, at $4.44 per dose, approaches the DTP in ‘taxation’. This is tacit acknowledgement by the government that the pertussis vaccine carries the highest risk of them all.

No Placebo-Controlled Trials of Whole-Cell Vaccine Since 1950 – All Post-Vaccination Research in The Last 60 Years Shows Health Damage

No randomised placebo-controlled trials of whole-cell vaccine have been performed since the 1950s, when diagnostic methods were different. Indeed, in the early 1990s, the Institute of Medicine (IOM), which spent 20 months studying all the available data on vaccinations, confirmed that no controlled clinical trials have ever been conducted to rule out whether the vaccine can cause chronic neurological damage, blood disorders, juvenile diabetes, Guillain-Barre paralysis and learning disabilities. With the most controversial vaccine in history, most questions about safety have never been asked.
The only large-scale study ever conducted in the US, at University of California at Los Angeles in 1979, found that one in 875 doses of DTP is followed by convulsions, or an episode of shock or collapse, leading to death in the case of two babies (Pediatrics, 1981; 68: 650-60). As for brain damage, a Swedish study showed a rate of brain damage or death of one in 17,000 children (BMJ, 1967; 4: 320-3).

The IOM report concluded that: the triple shot definitely causes anaphylactic shock and extended periods of inconsolable crying or screaming evidence is consistent with a causal relationship between acute encephalitis (inflammation of the brain) and shock and unusual shock-like (hypotonia/hyporesponsive) reactions, causing total collapse (Stratton K, Adverse Events Associated with Childhood Vaccines; Evidence Bearing on Causality, Washington, DC: National Academy Press, 1993).

In 1993, The National Childhood Encephalopathy study: a 10-year follow-up reported on the medical, social, behavioural and educational outcomes after serious, acute, neurological illness in early childhood. The analysis found a four-fold increase in the estimated risk of encephalitis from the pertussis vaccine. The analysis showed the risk of encephalitis with the vaccine have been grossly underestimated.

Diphtheria and tetanus toxoids and whole-cell pertussis vaccine (DTP) and pediatric diphtheria and tetanus toxoids (DT) are not recommended for individuals 7 years of age or older due to increased adverse reactions. Yet in 1994, a study in the Family Practice Research Journal found that children 7 years of age or older are inadvertently receiving DTP or DT and were unnecessarily experiencing adverse reactions.In another study in the The Journal of the American Medical Association, children vaccinated with pertussis vaccine were six times more likely to develop asthma. In 2004, a study in the British Medical Journal found that the prevalence of asthma and wheezing in non-vaccinated individuals was approximately 50% less at age 69-81 months than children who had 3 or more doses of with the Diptheria and tetanus vaccine.Researchers reported in the OSMA Journal that the pertussis vaccine may cause lasting and permanent brain damage. Physicians are required to warn all responsible parties of vaccine recipients that pertussis vaccine may cause “lasting brain damage”, but rarely if ever to Physicians inform parents of this fact.

In the Journal of Pediatrics researchers found an association observed between the DTP vaccination of preterm infants and a transient increase or recurrence of apnea where they would stop breathing.

New England Medical Journal reported
 in 2001 that the DTP vaccine increases the risk of febrile seizures fivefold on the day of vaccination and that there are significantly elevated risks.

According to the Anti-Aging Manual: The Encyclopedia of Natural Health, DTP vaccines may cause Sudden Infant Death Syndrome (SIDS) – 85% in 1 -6 months, same as the 2-4-6-month DTP vaccinations risk; the death rate increases eight times within 3 days of injection; in one study 70% of SIDS deaths occurred within 3 weeks of DTP vaccinations causes reported adverse reactions in 100 per 1000 vaccinations (10%).

In a hard hitting editorial in the Indian Journal of Medical Ethics (IJME),Dr. Jacob Puliyel, head of pediatrics at St Stephens Hospital in New Delhi, reports on detailed investigation into the deaths of children in Bhutan, Sri Lanka, India and Vietnam following use of Pentavalent vaccine. This vaccine combines the Diphtheria, Pertussis, Tetanus or DTP vaccine. (See WHO Caught Falsely Stating Pentavalent Vaccine Was Safe After It Was Discontinued In Some Countries Due To Deaths In Children)

Several other research citations linking the DTP vaccines to diseasehave they cause complications in neurological systems, the central nervous system, sudden death, cervical lymphadenitis and convulsions.Former FDA Commissioner David Kessler wrote in the Journal of the American Medical Association that “only about 1% of serious adverse events are reported to the FDA.” This study confirms the systematic under-reporting bias against vaccine adverse reactions. So we could reasonably multiply the incidence in VAERS reports by 100 to get a better handle on the magnitude of the problem. Apparently, no number of VAERS vaccine adverse reaction reports is sufficient to cause the FDA or CDC to raise a red flag or withdraw a vaccine from the market.Sources:
iom.edu
healthy.net
vaccinenewsdaily.com

         

Vaccination Opt-Outs Found to Contribute to Whooping Cough Outbreaks in Kids.


Several factors may be contributing to recent whooping cough outbreaks, but parents’ refusal to immunize their children is one

A California whooping cough epidemic in 2010 was one of the worst U.S. outbreaks of the disease in the past several decades. Ten infant deaths occurred among the more than 9,000 cases—the most in that state since 1947. Now, a study reveals that parental refusals to vaccinate their children may have played a part in that epidemic and possibly in a concurrent nationwide resurgence of the disease. The research found significant overlaps of areas with high numbers of whooping cough cases and areas where more parents had sought legal exemptions to opt out vaccinating their children.

 

CAUSE FOR WHOOPING COUGH‘S RESURGENCE?: Research shows California’s rates of nonmedical vaccine exemptions tripled from 0.77 percent in 2000 to 2.33 percent in 2010, and some schools had 2010 nonmedical exemption rates as high as 84 percent.

 

Whooping cough, or pertussis, is a highly contagious bacterial infection in the lungs that causes violent coughing and sometimes lasts for months. A combination vaccine called the DTaP (for diphtheria,tetanus, and acellular pertussis) protects children up to six years old from pertussis, and a similar formulation called Tdap is used to protect older children and adults.Previous research has found, however, that neither vaccine, made from the pertussis toxin and other genetic pieces of the bacterium, is as effective as DTP vaccine, a preparation that contained the whole bacterial cell; it was discontinued in the 1990s. Accordingly, pertussis cases remained low when DTP was the standard of care—typically fewer than 5,000 U.S. cases annually—but made a comeback in the past decade.

Parents in many states may opt out of vaccinating their children by seeking legal exemptions to public school immunization requirements. All but two states—Mississippi and West Virginia—allow religious exemptions, and 19 states, including California, offer some variation of a philosophical or “personal belief” exemption, depending on the law’s language. California’s rates of nonmedical exemptions tripled from 0.77 percent in 2000 to 2.33 percent in 2010, and some schools had 2010 nonmedical exemption rates as high as 84 percent.

In the new study, published September 30 in Pediatrics, lead author Jessica Atwell and her colleagues mapped “clusters”—statistically unusual aggregations—of nonmedical exemptions for kindergartners between 2005 and 2010. Theresearchers identified 39 clusters of such opt outs, including one that covered nearly all of northern California. In each of these clusters the area covered contained a statistically higher concentration of kindergartners with exemptions than the areas outside the clusters. Atwell’s team then used a similar modeling method to identify two pertussis outbreak clusters—areas where the cases reached statistically higher numbers than the rest of California. One such cluster included most of central California between May and October 2010. The other included San Diego County between July and November 2010. Then the researchers analyzed the clusters’ overlap.

“The strength of our approach was not just to find out the clustering of cases but also the statistical significance of the clustering overlap,” says senior author Saad Omer, an associate professor at Emory University School of Medicine’s Vaccine Center. “This tells us whether the clustering is by chance or not.” Neither the clusters nor their overlapping was by chance. Census tracts within a nonmedical exemption cluster were 2.5 times more likely to be within a pertussis cluster, even after accounting for population characteristics including racial demographics, population density, household income, average family size, percentage of residents with a college degree and location within a metropolitan area. Residents living in a census tract within a nonmedical exemption cluster were 20 percent more likely to catch pertussis than those outside a cluster, the analysis revealed.

Past research has already revealed that the weaker vaccine is driving whooping cough outbreaks and epidemics in the past decade. The new findings reveal there is more to the story. “What this study tells us is that if more and more people choose not to get a vaccine,” says Paul Offit, director of the Vaccine Education Center at The Children’s Hospital of Philadelphia, “then you’ll have bigger and bigger outbreaks.” This study also backs up the results in a 2008 study led by Omer that similarly found overlaps in pertussis outbreaks and nonmedical exemptions in Michigan during an 11-year period.

Atwell, a PhD candidate in Global Disease Epidemiology and Control at the Johns Hopkins Bloomberg School of Public Health, says it is difficult to quantify the contributions of different factors to the resurgence of pertussis and that it is a multifaceted issue. “There are a lot of factors, including waning immunity from the vaccine, increased case detection and possible changes in circulating strains,” she says, “but our study shows that nonmedical exemptions and clustering of unvaccinated individuals may have also played a role.”

Public health efforts to prevent epidemics of infectious diseases typically rely onherd immunity: The more people in a community are vaccinated or otherwise protected from a disease, the less likely it is to be transmitted throughout the population. This approach is particularly crucial with pertussis, which is almost as contagious as measles and requires about 95 percent vaccination coverage to maintain herd immunity. Increasing numbers of parents opting out of vaccinating their children can erode this immunity. “When you look at statewide or countywide data, the increases in nonmedical exemptions don’t look that significant,” Atwell says, “but when you look at community-wide coverage, it is much lower than the threshold needed to maintain herd immunity in some areas.”

Unvaccinated individuals in the 2010 epidemic were eight times more likely to contract pertussis than vaccinated ones. But unvaccinated individuals pose risks to the community as well. “It’s a choice you make for yourself and a choice you make for those around you,” Offit says. “Infants need those around them to be protected in order not to get sick. We have a moral and ethical responsibility to our neighbors as well as to ourselves and our children.”

Data has shown exemptions are more prevalent where they are easier to obtain. In California parents currently can obtain exemptions simply by signing a form. A law takes effect there next year requiring parents to meet with a health care provider before obtaining an exemption. “I hope the legislation will help address the increased risk for pertussis and raise immunization rates in those areas,” says Richard Pan, a pediatrician and member of the California State Assembly who sponsored the bill. He says the law may not effect much change in areas with strong pockets of vaccine-refusing parents, but he hopes more of the parents feeling uncertain about immunization will realize the benefits after getting accurate information from a health care professional.

Parents who turn down vaccinations for their children are often misinformed aboutthe safety and effectiveness of vaccines. “I don’t think people understand that our control of vaccine-preventable diseases such as pertussis and measles is fragile,” Atwell says. “We need to continue to educate people about the implications of not vaccinating their children.”

 

 

 

 

 

Missouri Offers Free Vaccinations for Whooping Cough.


What do you do when you are offered something free? If you’re like most people, you accept it, oftentimes when it’s something you will never use or don’t even like. So, when a state offers free vaccines, those with limited knowledge of their negative effects may begin lining up. Unfortunately, flu season is approaching, so millions will line up for this questionable anti-flu solution.

That’s the concern of Michelle Goldstein at VacTruth.com. Goldstein reports on a recent incidence in Missouri, where state officials launched a propaganda campaign aimed at vaccinating as many in the state as possible, by offering free Tdap vaccines in the St. Louis area.

The “giveaway” was recently announced in St. Louis, where the paper announced that incidence of whooping cough have risen to levels not seen since 1955, due in part because vaccinations given more than 10 years ago were wearing off. Last year, more than 41,000 cases of pertussis were reported nationwide; this is in contrast to 18,719 cases the year before.

vaccine_fast-263x164

While St. Louis Today and the Missouri Department of Health are quick to point out all of the scary effects of whooping cough, they neglect to discuss the scary effects of the Tdap vaccine and the fact that pertussis can be effectively treated without conventional pharmaceutical means.

According to Goldstein:

“Health consequences resulting from the Tdap vaccine include encephalitis, brain damage and death. A comprehensive report made by the National Vaccine Information Center (NVIC) documents clearly the widespread health dangers associated with the Tdap vaccine. Tdap and DTap vaccines are currently used in the United States, replacing the DTP vaccine in 1996, but all three vaccines contain the dangerous pertussis toxin with unsafe additives.”

Exposing the Vaccination-Immunity Fraud

Also interesting, most of those who have recently contracted pertussis were actually vaccinated at some point. In other words, while there is solid proof of the vaccinations causing harm, there is no solid evidence that it can definitively prevent the disease.

In addition, whopping cough can be treated without prescription drugs. As a matter of fact, a successful bout of pertussis means lifelong immunity. In other words, once you have it you won’t get it again. What’s the most effective treatment for whooping cough? A vitamin C protocol that can dramatically reduce symptoms and complications.

Finally, the other conditions this Tdap vaccine “protects” against—tetanus and diphtheria—are not only uncommon in the U.S., but can similarly be prevented and treated with risk of complications being relatively low.

Since whooping cough can be problematic for young children, it’s important to do whatever you think is best as a parent; it’s just important to know truths behind the chosen solution.

Whooping Cough Vaccine Can Cause Brain Damage And Death.


 In July, the state of Missouri began offering for free a vaccine aimed at preventing, among other ailments, whooping cough. According to officials, the TDap vaccine, which reportedly prevents tetanus, diphtheria and pertussis, was necessary because “of the rising incidence of whooping cough is reported to be related to the vaccine wearing off if given more than ten years earlier,” says an online report.

Citing a St. Louis Post Dispatch article, Michelle Goldstein of VacTruth.com says some 41,000 cases of pertussis occurred in the U.S. in 2012, compared to less than 19,000 cases in the previous year – thus the need for the new vaccine.

“The news story emphasized that whooping cough is highly dangerous and can lead to vomiting and death, especially in children. The report indicates that diphtheria is a bacterial disease that is highly contagious and can also lead to death,” Goldstein writes, adding that tetanus can cause severe muscle spasms.

Natural remedies, treatments can work without risk

What the paper failed to report, however, is that there are serious health risks associated with the Tdap vaccines. Also, there are relatively benign health implications that are commonly associated with the diseases the vaccine is intended to prevent – “along with the important fact that vaccines have never been proven to prevent any disease,” Goldstein said.

She adds:
The risks that WHOOPING COUGH, diphtheria and tetanus pose to health are low compared to the potential, serious dangers reported as a result of this vaccine. Whooping cough can be treated successfully through a vitamin C protocol developed by Dr. Suzanne Humphries which has been shown to greatly reduce symptoms. In contrast, antibiotic treatments, given routinely by conventional, allopathic physicians to treat whooping COUGH, have never been shown to positively impact the course of the illness.
Whatever the standard medical treatments, most people fully recover from whooping cough, which then gives them lifetime immunity from it. If they should become re-infected, Goldstein writes, subsequent episodes are generally “quite mild.”

Meanwhile, tetanus can be prevented in a number of ways without ever receiving a VACCINE. For instance, simply thoroughly washing and cleaning cuts can prevent the disease. And in actuality, contracting the disease in the first place is rare; just “233 cases of tetanus were reported to the Center for Disease Control between 2001 and 2008,” Goldstein points out, citing the federal agency’s own figures. “The incidence of tetanus declined by more than 95% between 1947 and 2008.”

Finally, diphtheria is also a low-risk disease, and one that is not seen widely in the U.S. since an outbreak in the 1970s. Over the 30-year period between 1980 and 2010, just 55 cases of the disease were reported to the CDC.

Vaccine dangers outweigh risk of actually getting the disease

The dangers of getting a Tdap vaccine can also be significant. According to Goldstein:

Health consequences resulting from the Tdap vaccine include encephalitis, BRAIN DAMAGE and death. A comprehensive report made by the National Vaccine Information Center (NVIC) documents clearly the widespread health dangers associated with the Tdap vaccine. Tdap and DTap vaccines are currently used in the United States, replacing the DTP vaccine in 1996, but all three vaccines contain the dangerous pertussis toxin with unsafe additives.

Furthermore, experts note, the fact that whooping cough even occurs in “vaccinated” populations is a sign that vaccines are not effective at preventing the disease.

Sources: Raw For Beauty

 

Effectiveness of pertussis vaccines for adolescents and adults: case-control study.


Abstract

Objective To assess the effectiveness of reduced acellular pertussis (Tdap) vaccines in adolescents and adults.

Setting Kaiser Permanente Northern California.

Design Case-control study.

Participants All polymerase chain reaction (PCR) confirmed cases of pertussis in members aged 11 years and older from January 2006 to December 2011. We compared the Tdap vaccination status of PCR positive cases with two control groups: people testing negative for pertussis by PCR and closely matched people from the general Kaiser Permanente Northern California population.

Main outcome measure PCR confirmed pertussis. The association of Tdap vaccination with the odds of pertussis infection was estimated by conditional logistic regression, with adjustment for calendar time, pertussis vaccine type received in early childhood, age, sex, race or ethnic group, and medical clinic. We calculated Tdap vaccine effectiveness as 1 minus the adjusted odds ratio.

Results The study population included 668 PCR positive cases, 10 098 PCR negative controls, and 21 599 Kaiser Permanente Northern California matched controls. Tdap vaccination rates were 24.0% in PCR positive cases and 31.9% in PCR negative controls (P<0.001). The adjusted estimate of effectiveness of Tdap vaccination against pertussis was 53.0% (95% confidence interval 41.9% to 62.0%) in the comparison with PCR controls, and 64.0% (55.5% to 70.9%) in the comparison with Kaiser Permanente Northern California controls.

Conclusion Tdap vaccination was moderately effective at preventing PCR confirmed pertussis among adolescents and adults.

 

Discussion

We found that tetanus toxoid, reduced diphtheria toxoid, and reduced acellular pertussis (Tdap) vaccination was moderately effective at preventing pertussis in people aged 11 years and older during a study period that included the large outbreak in California in 2010 and 2011. Tdap vaccination was estimated to reduce the risk of polymerase chain reaction (PCR) confirmed pertussis in our study population by 53% (95% confidence interval 42% to 62%) in the comparison with PCR negative controls and by 64% (56% to 71%) in the comparison with Kaiser Permanente Northern California controls. Both estimates of vaccine effectiveness and the range covered by their confidence intervals indicate that Tdap vaccination was moderately protective against pertussis.

In subgroup analyses, we found that the Tdap booster was moderately effective both in older people who had received all whole cell pertussis vaccines as infants and in younger people who had received all acellular pertussis vaccines. Yet, rates of pertussis were highest in the acellular subgroup consisting of young adolescents ages 11-14, probably because protection from their childhood doses waned substantially over time.13 30 As a result, the absolute benefit of Tdap vaccination was much greater for people who had received acellular instead of whole cell vaccines as children. Strategies to decrease the incidence of pertussis should prioritize giving the Tdap booster to people who received only acellular pertussis vaccines as children, as California has done since the 2010 outbreak, requiring Tdap vaccination for middle school students. To our knowledge this is the first study to assess the effectiveness of the Tdap booster in members of this new generation that has received all acellular vaccines.

We had limited power to assess the effectiveness of Tdap vaccines in the subgroup of people born before 1950. The confidence interval suggests that effectiveness was unlikely to be higher than 68%. This subgroup was at low risk of pertussis, perhaps as a result of immunity conferred by natural infection, receipt of single antigen whole cell vaccines available before the whole cell pertussis combination vaccines, or less frequent contact with infected people; this subgroup also had low Tdap vaccination coverage, since it was not until 2012 that the US Advisory Committee on Immunization Practices recommended routine Tdap vaccination for people aged 65 years and older.

Prior post-licensure studies of Tdap vaccine effectiveness have been limited by low numbers of cases. One controlled study showed vaccine effectiveness of 92% (95% confidence interval 32% to 99%) in preventing clinical pertussis,21but there were only 10 people who met the definition of a primary case. More recently, another study investigating a pertussis outbreak in the US Virgin Islands found vaccine effectiveness of 66%22 in an analysis of 51 confirmed or probable pertussis cases. An observational study from Australia23 evaluating a mass vaccination program for high school students, found vaccine effectiveness of 78.0% (95% confidence interval 60.7% to 87.6%) based on 167 cases.

Source: BMJ

Pertussis Immunity Drops Soon After the Last Vaccine Dose Is Given.


The incidence of pertussis in children rises steadily in the years immediately following receipt of the fifth dose of the diphtheriatetanusacellular pertussis (DTaP) vaccine, according to a study in Pediatrics.

Researchers examined the incidence of pertussis among more than 400,000 children in Minnesota and Oregon who’d received all five doses of DTaP, with the fifth dose given between ages 4 and 6 years. In the 6 years after the last dose was received, some 550 pertussis cases were identified. The incidence rose steadily with each passing year.

The authors say their findings “strongly [suggest] waning of vaccine-induced immunity,” which “helps to explain the emergence of an increased burden of disease among 7- to 10-year-olds.” (Currently, the adolescent booster is recommended at ages 11 to 12 years.)

Source: Pediatrics

Pertussis on the Rise.


Pertussis reached epidemic proportions in Washington State in 2012, apparently because of waning immunity in individuals who received acellular vaccines during childhood.

Pertussis incidence has been increasing since mid-2011 in the state of Washington. The number of cases reported in early 2012 — 2520 — was 1300% higher than the number during the same period in 2011. Rates were highest among infants aged <1 year, children aged 10 years, and adolescents fully vaccinated with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine. Incidence among Hispanics was more than twice that among non-Hispanics (53.1 vs. 24.6 cases per 100,000 population).

A total of 2069 cases were confirmed by laboratory testing (83%) or epidemiologic linking (17%). Multitarget polymerase chain reaction (PCR) assays, performed on 193 specimens in which Bordetella DNA had been detected by PCR, identified B. pertussis in 175 (91%) and B. parapertussis in 11 (6%). Thirty (55%) of the 55 isolates subjected to pulsed-field gel electrophoresis represented the four most commonly identified profiles in the CDC’s national database.

Valid vaccination history was available for 91% of the patients aged 3 months to 19 years. Seventy-six percent of the patients aged 3 months to 10 years were up to date with childhood diphtheria and tetanus toxoids and acellular pertussis doses; 43% of those aged 11 to 12 years and 77% of those aged 13 to 19 years had received the Tdap vaccine recommended for older children and adults.

Although the incidence of pertussis nationwide in early 2012 was far lower than that in Washington State (4.2 vs. 37.5 cases per 100,000), it also peaked among infants and among children aged 10, 13, and 14 years. Across the U.S., the case fatality rate showed a slight decrease from the previous decade.

Comment: Acellular vaccines replaced the older whole-cell products because of adverse events associated with the latter. It now appears that protection by the acellular vaccines, although lasting several years, may wane, leaving large populations unprotected against pertussis. Nonetheless, vaccination and revaccination remain the primary shields against infection.

Source: Journal Watch Infectious Diseases.