Prenatal TDap Vaccination: Preventing Whooping Cough in Infants- A Thesis (Part 2)

Last week, I wrote on the importance of the tetanus, diphtheria, and acellular pertussis (Tdap) vaccination for pregnant women, and included the introduction to my thesis paper in order to illuminate the problem, as it stands, in California. I discussed the 39% rate of prenatal vaccinations in Kern County and had just began to postulate what could be causing such a low rate. My research did not take me down the route of talking to pregnant women and determining their opinions regarding vaccination. Instead, what I wanted to focus on was the source of prenatal vaccinations and accompanying education- prenatal care providers.

This research targeted the doctors and nurse practitioners who administer prenatal care in Kern County, CA. What were the doctors’ attitudes regarding prenatal Tdap? How educated were they on the necessity and timeframe for administering the prenatal Tdap? In order to obtain the answers to these questions, I (with the help of the Kern County Department of Public Health) created surveys aimed at asking the doctors many questions regarding their practices and processes. I’ll summarize my findings here, but check out the link below to access my completed thesis (with charts included)!

One of the interesting things that I noticed about prenatal care providers was that not all of them were recommending the vaccination at 28 weeks. 28+ weeks of gestation is the widely accepted time for administering the vaccination due to the fact that this is prime time for antibodies to be shared between mother and fetus, while still giving both enough time to build up immunities. Some doctors, however, recommended the vaccine outside of this accepted window. A few doctors suggested the vaccine as early as 12 weeks, while some would not administer until the patient delivered her child.

You see, the 28+ weeks timescale is very important when it comes to administering Tdap to expectant mothers. Administer it too early, and the fetus may not be developed enough to make use of the fresh supply of antibodies. Delivering it too late, such as at delivery, will protect the mother- but does not give enough time or ability to also spread immunity to the child.

I also looked at whether or not practitioners stocked the shot at their facility. The reason this question was so important was due to the fact that prior research has shown that when patients are referred to a secondary location to receive their vaccination, they are much less likely to follow through with their referral. For example, when it came to prenatal flu shots, patients were only 33.5% likely to receive their flu shot when they were referred, compared to 67.9% when it was administered at their doctor’s office. Let me clarify this… women were almost doubly likely to get vaccinated when they were able to receive their shot at their doctor’s office, rather than when they were sent to the nearest pharmacy.

In Kern County, 77% of private practitioners do not currently stock the vaccine at their location and instead rely on referrals to ensure their patients become vaccinated. The referrals, however, are little more than suggestions. In fact, most private practitioners verbally referred their patients- with only half even documenting their referral in the patient’s chart. What’s even more, is that there is virtually no follow-up occuring in practitioners’ offices. In most cases, doctors will recommend the prenatal Tdap once, and then never mention it again.

When patients actually followed the referral and received their shot, only 27% of private practitioners in Kern County documented such in their records. When it came to documenting patient refusals, however, practitioners were much more likely to do so- with 84% of those interviewed admitting to such a process. Some reasons that doctors found for their patients refusing the prenatal Tdap had to do with safety concerns and not understanding the need for the vaccine, showing that we could still make great strides with effective education.

In order to increase the rate at which pregnant women receive their Tdap, it might become necessary to standardize processes to ensure that doctor’s are discussing the prenatal Tdap more with their patients, and are documenting referrals and follow-ups. It might also be important to encourage private practitioners to stock Tdap at their office in order to make it easier on their patients, who already have so much going on in their lives.

So there it is- the culmination of 6 months of research and analysis summarized in a couple short blog posts. There were more results than just what I wrote here, though they weren’t the highlight of my research. However, if you would like to read more- or if you are just looking for something to help you with your insomnia- I have included the link to my entire thesis below. As a bonus, for those of you who don’t like to read, I have also included a powerpoint slide that summarizes my findings. Enjoy!

Thesis: https://1drv.ms/w/s!Al5M_iJL5E_vs0Hp1Zk_aCiEvGlC

PowerPoint: https://1drv.ms/p/s!Al5M_iJL5E_vsRsEECsQxAlTY57z

Prenatal TDap Vaccination: Preventing Whooping Cough in Infants- A Thesis (Part 1)

Well, after 10 painstaking long years of school, maintaining a full time job while attending part time, I’ve finally managed to achieve a Master’s in Public Health.

I’ve written many a research paper, some that will be published here… but none so in depth as my final thesis, simply titled “Prenatal Tetanus Diptheria, and Acelullar Pertussis Vaccination Rates in Kern County, California.”

Sounds like a real bore, doesn’t it? Well, if you have no interest in the wonder of vaccinations and their ability to prevent unnecessary death, then you would be right.

I’ll post my introduction below, but for those of you still reading, let me explain the purpose for this research and what it entailed.

California has a whooping cough problem. About every 4 or 5 years, the state endures a sweeping epidemic of the disease. For most people, whooping cough is an annoyance at worst, creating a persistent cough and just a few days of fever. For the very young, those too young to be vaccinated incidentally, an exposure to whooping cough can mean death.

The thing is, we have recommendations in place to prevent infants from contracting whooping cough. A double barrier system has been developed that involves vaccination of all family members as well as a third trimester vaccination for the expectant mother. On the one hand, family vaccinations will lower the incidence of the infant coming into contact with the bacteria, while the pregnant mother’s vaccination while will promote the passive transfer of antibodies to the developing child.

In Kern County, CA- there seems to be a disconnect when it comes to receiving the all important prenatal vaccination. And while recent research has pointed to the fact that full family vaccinations are becoming unfeasible, and in some cases inefficient, prenatal vaccinations are more important than ever.

Yet only 39% of pregnant women are receiving their prenatal vaccinations in Kern County, CA.

What is going on here? Why are prenatal vaccination rates so low? And what can we do to improve those rates? These are the questions my thesis sought to answer by traveling all across the county and looking at the processes OB/GYNs have in place to help them ensure their patients obtain their vaccinations.

I’ll copy/paste the introduction to my thesis below, but you’ll have to wait a bit for my results follow-up blog post. In the meantime, I hope this gets you thinking about the importance of prenatal vaccinations.

Prenatal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Rates
In Kern County, California

INTRODUCTION

In 2016, Kern County, CA saw the death of an infant due to the preventable disease pertussis (Long, 2012). The child, who was less than 6 months old at the time of death, was at an
age that is most vulnerable and least protected from the disease. Just six years prior to this death, California saw an outbreak of pertussis sweep across the state, infecting over 9,000 people while hospitalizing 800 (Long, 2012). During this epidemic, the infection and subsequent complications took the lives of 10 infants (Long, 2012).

Infants remain one of the most vulnerable populations to pertussis outbreaks due to their still developing immune systems and their inability to receive the pertussis vaccination until they are 8 weeks old (Kharbanda, et al, 2016). To protect infant lives, the Centers for Disease Control
and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG) have enacted recommendations for women in their third trimester to receive the tetanus,
diphtheria, and acellular pertussis (Tdap) vaccine so that they may prevent spreading the disease to their newborn while also creating passive immunity for the fetus (CDPH, 2016).

Even though the recommendations for prenatal pertussis vaccinations are widespread and well-known, the state of California has been unable to achieve a vaccination rate of even half of the population of prenatal patients (CDPH, 2016). Kern County, specifically, has one of the lowest rates of prenatal Tdap vaccinations in the state (CDPH, 2016). The purpose of this research is to identify some of the possible reasons for the low rate of prenatal vaccinations within Kern County, CA. This research also seeks to understand any barriers that pregnant women may have in receiving their pertussis vaccination in a timely manner.

Disease Description

Bordetella pertussis is an infectious gram-negative bacterium known for causing the disease pertussis, better known as whooping cough. It is a toxin producer, and promotes disease
in individuals by attaching itself to the cilia of the respiratory epithelial cells and paralyzing the cilia. This causes inflammation of the respiratory tract to occur, which then interferes with
pulmonary secretions from getting cleared. This creates cold-like symptoms approximately 7-10
days after the original exposure; though the first symptoms have been known to form up to 21 days after first exposure.

The first stage of symptoms, known as the catarrhal stage, includes
sneezing, a runny nose, a low-grade fever and an occasional cough. After 1 to 2 weeks of this, the second stage, known as the paroxysmal stage, begins. (Centers for Disease Control and
Prevention, 2015). Pertussis is not suspected until the paroxysmal stage of the disease begins. It is at this
stage where the coughing becomes much more rapid and excessive in number. This coughing is
often accompanied by a high pitch whoop, explaining the name whooping cough. Between
coughing attacks, the patients often have no other symptoms and appear to be perfectly healthy.
During attacks, however, patients may begin to turn blue or become cyanotic. This stage of the disease is especially serious for infants and young children, who will become very ill and appear
distressed. The paroxysmal stage usually lasts between 1 and 6 weeks, but has been known to last up to 10 weeks. (Centers for Disease Control and Prevention, 2015).

The final stage of the disease, known as the convalescent stage, is often the same as the recovery stage. During this time, approximately 2-3 weeks, the cough begins to go away and
occur less over time. If a patient contracts only pertussis during this time, the cough will completely disappear by the end of this stage. It is only in those who have complications and subsequent respiratory infections that will often experience the paroxysmal cough for months
after the initial onset. (Centers for Disease Control and Prevention, 2015).
Pertussis can be an incredibly contagious disease. Its basic reproductive number (R0) is at
a rate of 12 to 17, meaning that each person who becomes infected with whooping cough will then pass that infection to no less than 12 to 17 other people (Clark, Messonnier, and Hadler,2012). Vaccination against the disease is really the only mode of defense against the infection.

Infants remain the most vulnerable population simply because they cannot be vaccinated until 8 weeks at the earliest, and even then, do not boast complete immunity until about a year of age (CDPH, 2016). When it comes to protecting infants, research has proven that one of the most effective ways to prevent transmission is the process of cocooning (the act of inoculating those
who encounter the infant) together with a prenatal Tdap administered to expectant mothers between 27 and 36 weeks of pregnancy with each pregnancy, regardless of past immunizations (Peters, et al, 2012; CDPH, 2016).

Kern County, California

Kern County, California is a county located north of Los Angeles County with a land area of approximately 8,132 square miles. It contains a moderate population of over 880,000 people.
Of the entire county’s population, 42% live within the boundaries of what is probably considered the only city in the county: Bakersfield, CA. Outside of Bakersfield, the county is made up of
small townships and unincorporated areas. Kern County also boasts the presence of Edwards Air Force Base, as well as many agricultural and oil drilling areas (U.S. Census Bureau, 2017). Pertussis is endemic to Kern County and often cycles through

epidemics every 3-5 years.
By tracking the last few years of pertussis incidences, data shows that the highest incidence of disease often occur in the spring and summer months (CalREDIE, 2017). The most recent epidemic in Kern County occurred in 2014, and lasted months into 2015. Most outbreaks in Kern
County have been shown to occur in the spring and fall months.

On average, Kern County has a population of 100.3 people per each square mile. A little over 34.8% of the population claims white (not Hispanic), and 52.8% of the population claims Hispanic. Over 22% of the county lives in poverty and the median household income is just under $50,000 a year. In comparison, the whole of California has a poverty rate of 14.3% and a median house income of over $63,000— placing Kern County below the state average. (U.S. Census Bureau, 2017).

Kern County, CA has one of the lowest rates of prenatal Tdap— with just 39% of expectant mother receiving the vaccination (CDPH, 2014; CDPH, 2016). This makes Kern County the fourth lowest county for receiving prenatal Tdap vaccinations (CDPH, 2016). In comparison, many of the northern counties, such as San Francisco and Santa Clara, maintain prenatal vaccination rates of almost eighty percent (CDPH, 2016). California, on average, has close to a 50% prenatal vaccination rate (CDPH, 2016). The rate of prenatal Tdap vaccinations in
Kern County is lower than the state rate, even as pertussis epidemics remain cyclically endemic
to the location. The preventable death of even one infant in Kern County is reason enough to try and determine why the prenatal vaccination rates are so low to develop ways in which we can
improve these rates.

This research seeks to uncover reasons why only 39% of Kern County’s expectant mothers are receiving the prenatal Tdap vaccination. This study will outline the background of pertussis in California as well as past vaccination recommendations that have been in place to promote infant protection against pertussis. It will also review the current data and trends regarding pertussis vaccination and incidence of disease in Kern County versus the state to provide context for the research. A study of Kern County’s prenatal care providers will assist in determining what interventions may be necessary to improve the prenatal Tdap vaccination rates.