Columbus, Ohio - Recent local headlines have erupted warning of whooping cough (pertussis) outbreaks in Ohio school districts, but are they telling the whole truth?

Whooping cough or pertussis is a respiratory infection caused by bacteria, Bordetella pertussis. It is spread to others (transmission) via tiny water droplets when an infected individual is talking, coughing or sneezing. It begins with cold-like symptoms but progresses to rapid uncontrollable coughing spells within several days. 

The Center for Disease Control and Prevention (CDC), medical trade organizations, and medical professionals are quick to assert that getting vaccinated is the best course of action to prevent whooping cough (pertussis) and protect vulnerable members of the community. The whooping cough vaccine is DTaP or TDaP and is actually a combination of diphtheria, tetanus, and pertussis. This vaccine is recommended to be given to a child 6 times by the time they are 12 years old.

Dr. Nancy Pook with Kettering Health Network recently stated some issues with the DTaP/TDaP vaccine: “The problem is it doesn’t eliminate all. The vaccines wane off and maybe the Bordetella is evolving or mutating a little bit, we’re not sure 100 percent of the reason why that there’s more pertussis. But it’s still present worldwide.” 

What Dr. Pook is describing is primary, secondary, and tertiary vaccine failure. Primary vaccine failure is when an individual is vaccinated but does not develop immunity. Secondary vaccine failure is when an individual is vaccinated, develops immunity but loses immunity over time. Tertiary vaccine failure is when the organism, bacteria or virus, mutates or changes so the vaccine is no longer effective.

Can a toxin mediated vaccine, such as DTaP/TDaP, provide protection against infection and transmission? 

In 2017 Christopher Gill, associate professor of global health at the Department of Global Health at Boston University School of Public Health, stated: "this disease is back because we didn’t really understand how our immune defenses against whooping cough worked, and did not understand how the vaccines needed to work to prevent it. Instead we layered assumptions upon assumptions, and now find ourselves in the uncomfortable position of admitting that we may made some crucial errors. This is definitely not where we thought we’d be in 2017.”

Despite sustained high pertussis vaccination rates of > 95%, the United States has experienced a resurgence of pertussis over the past 30 years. According to the CDC’s 2018 Provisional Pertussis Surveillance Report, 41% of all infections occurred in children age six months to six years who had received more than three doses of DTaP vaccine, compared to only 10% of disease cases involving unvaccinated children.  

An alarming discovery from a Springboro, Ohio whooping cough outbreak reveals that of the 37 cases, 100% had received all or some of the recommended DTaP/TDaP doses:

An important observation within the recent scientific literature is the phenomenon of asymptomatic carriers. When exposed to Bordatella pertussis, vaccinated individuals become infected but do not show the telltale signs of infection. Yet they are fully capable of spreading the bacteria to others, including infants and the immune compromised. 

A U.S. Food and Drug Administration study reported:  

“The observation that aP [acellular pertussis vaccine], which induces an immune response mismatched to that induced by natural infection, fails to prevent colonization or transmission provides a plausible explanation for the resurgence of pertussis and suggests that optimal control of pertussis will require the development of improved vaccines.” (1)

The scientific literature also includes studies of mutations and bacterial type replacement proposed as causes for increasing rates of pertussis disease.

A study published in 2015 reported:

“The significant association between vaccination and isolate pertactin production suggests that the likelihood of having reported disease caused by PRN– [Pertactin Negative] compared with PRN+ [Pertactin Positive] strains is greater in vaccinated persons. Additional studies are needed to assess whether vaccine effectiveness is diminished against PRN– strains.” (2)

Unfortunately, public health agencies, medical trade organizations and media outlets fail to warn those who are vaccinated with DTaP/TDaP that regardless of vaccination status they need to be aware they are still at risk of infection and that vaccinated individuals are capable of unknowingly spreading pertussis to others. If you have been exposed to whooping cough, regardless of vaccination status, you should ask your doctor to perform a test that will determine if you are infected. This will ensure that treatment is started in a timely manner and will prevent unnecessary exposure to others.

A recent news article reported:

"Melissa Wervey Arnold, CEO, Ohio Chapter, American Academy of Pediatrics, said the best defense is vaccination, especially anyone who is going to be around infants who aren’t fully vaccinated.

Immunity, whether from getting the vaccine or from having the disease, typically wears off within five years, leaving previously immune children susceptible again by adolescence. Individuals and families providing care to a new baby may need a pertussis booster shot to provide protection for infants who haven’t had a chance to get the full series of vaccinations yet."

What is being described above is a theory called cocooning, a strategy to protect infants and other vulnerable individuals from infection by vaccinating those in close contact with them. According to this study, cocooning is ineffective when a vaccinated individual can be an asymptomatic carrier of Bordatella pertussis:

“We find that: 1) the timing of changes in age-specific attack rates observed in the US and UK are consistent with asymptomatic transmission; 2) the phylodynamic analysis of the US sequences indicates more genetic diversity in the overall bacterial population than would be suggested by the observed number of infections, a pattern expected with asymptomatic transmission; 3) asymptomatic infections can bias assessments of vaccine efficacy based on observations of B. pertussis-free weeks; 4) asymptomatic transmission can account for the observed increase in B. pertussis incidence;  and 5) vaccinating individuals in close contact with infants too young to receive the vaccine (“cocooning” unvaccinated children) may be ineffective.” (3)

Providing clear, concise, accurate and honest information is necessary to protect and improve the health of all Ohioans by preventing infection which includes the prevention of pertussis exposure to Ohio’s most vulnerable individuals via asymptomatic carriers, it is in Ohio’s best interest that:

1. Public health departments, medical trade organizations, and medical professionals educate the public that in the event of a pertussis outbreak, all people exposed to pertussis should be tested for pertussis, whether or not they have symptoms and regardless of vaccination status;
2. Track pertussis infection based on bacterial strain type to determine differences in attack rate between strains;
3. Include the asymptomatic infections, strain types, and vaccination status of pertussis cases in the Annual Summaries of Infectious Disease report published by the Ohio Department of Health.

References:

1. Warfel J, et al. Acellular pertussis vaccines protect against disease but fail to prevent infection and transmission in a nonhuman primate model. PNAS 2014; 111(2):787-792. 
2. Martin, S, et al. Pertactin-Negative Bordetella pertussis Strains: Evidence for a Possible Selective Advantage. Clinical Infectious Diseases 2015; 60(2):223-7.
3. Althouse B, et al. Asymptomatic transmission and the resurgence of Bordetella pertussis. BMC Medicine 2015; 13:146.

Additional References (not cited):

1. Hovingh E, et al. Emerging Bordetella pertussis Strains Induce Enhanced Signaling of Human Pattern Recognition Receptors TLR2, NOD2 and Secretion of IL-10 by Dendritic Cells. PLoS One 2017. DOI:10.1371/journal.pone.0170027 
2. Sala-Farre M.R., et al. Pertussis epidemic despite high levels of vaccination coverage with acellular pertussis vaccine. Enferm Infecc Microbiol Clin. 2015; 33(1):27-31. 
3. Matthias J, et al. Sustained Transmission of Pertussis in Vaccinated, 1-5-Year-Old Children in a Preschool, Florida, USA. Emerging Infectious Diseases 2016; 22(2).
4. Haifa I, et al. Pertussis Infection in Fully Vaccinated Children in Day-Care Centers, Israel. Emerging Infectious Diseases 2000;(6)5.