Whooping cough vaccines could be causing a resurgence in deadly disease, scientists warn
(NaturalNews) The whooping cough (pertussis) vaccine may not actually prevent many people from becoming infected with the disease, according to a new study conducted by researchers from the Santa Fe Institute and published in the journal BMC Medicine on June 24. Instead, the vaccine may simply prevent such people from showing symptoms, even as they spread the disease to others.
The study is the latest to show that lowered vaccination rates are not to blame for a recent resurgence of the disease.
“There could be millions of people out there with just a minor cough or no cough spreading this potentially fatal disease without knowing it,” researcher Ben Althouse said. “The public health community should act now to better assess the true burden of pertussis infection.”
Vaccine does not prevent infection!
Whooping cough, named for the distinctive sound that patients make while inhaling after serious coughing fits, has become more common in recent years. Prior to 2002, there were an average of approximately 10,000 cases per year in the United States. In the past few years, the number of cases has averaged about three times as many. The most cases since 1955 occurred in 2012, with 48,000 cases, though numbers have fallen again since then.
Many vaccine advocates have claimed that lowered vaccination rates have caused this recent increase. But according to the new study, the increase can be attributed to a change made to the vaccine in the 1990s. Prior to this change, the vaccine was made with whole bacterial cells. Serious side effects from this formula led to the adoption of the new, “acellular” formulation, made with only traces of bacterial protein.
Less incidence of side effects seems to mean less effectiveness, however. A January 2014 study in the Proceedings of the National Academy of Sciences found that, in baboons, the new vaccine did not prevent pertussis infection or prevent infected animals from spreading the disease. It merely prevented them from developing symptoms.
In the new study, the researchers combined pertussis infection data, a detailed pertussis epidemiological model and genetic data on the pertussis bacterium. They concluded that the new vaccine has probably created an entire category of asymptomatic spreaders, directly fueling rising disease rates.
“Herd immunity” impossible?
The findings undercut several key assumptions of U.S. vaccination campaigns. First, they suggest that well over 99 percent of people would need to be vaccinated to confer “herd immunity.” Since the vaccine is only 80 percent effective even at giving people immunity to the disease’s symptoms, it is unclear if herd immunity is even possible for pertussis.
The findings also call into question the recommendation that parents and siblings get pertussis boosters in order to protect babies too young to be vaccinated. “It just doesn’t work, because even if you get the acellular vaccine you can still become infected and can still transmit. So that baby is not protected,” Althouse said.
The study also refutes the idea that parents who choose not to give their kids the DTaP vaccine are to blame for whooping cough outbreaks. In this, it mirrors the findings of another recent analysis of the pertussis vaccine, published in the journal PLOS Computational Biology on April 23. In that study, researchers used mathematical modeling to test several potential explanations for rising pertussis rates, including lowered vaccination rates, improved diagnosis and the change to an acellular vaccine.
The researchers found that the 10 percent drop in effectiveness of the vaccine wholly explained the bump in pertussis rates. No other hypothesis, including lowered vaccination rates, was able to explain the change.
Neither study is likely to change the party line that everyone should get vaccinated against pertussis, however. Both groups of researchers emphasized that everyone should still get the shot, while calling for more research to produce still a third form of pertussis vaccine.
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