So let me ask you: When was your last tetanus shot? Do you remember? What is diphtheria (and who gets that anymore)? And what’s up with whooping cough?
Many adults don’t remember the last tetanus vaccine they received. They also may not know that every tetanus shot also boosts immunity to diphtheria, so each booster provides protection for both. Adding the pertussis component — DTaP (2, 4, 6, and 15-18 months of age, with a kindergarten booster at 4-6 years) and Tdap at 11-12 years of age — provides protection against these potential killer pathogens throughout childhood. Before we discuss why adults need to stay protected throughout their lives from this triad of misery, a little history first.
Tetanus is caused by the ubiquitous soil bacterium Clostridium tetani. It is the only vaccine-preventable infection that is not transferred from person-to-person. (Herd immunity doesn’t apply in the case of tetanus, making it, in the modern age of vaccines, a rather pathetic way to die in the 21st century.) Rather, bacteria enter the body through broken or injured skin — from a contaminated-by-dirt laceration, puncture wound, crush injury, or burn — and within a few days to a few weeks, produce a toxin which causes severe and painful muscle spasms. These muscle spasms start in the face (“lockjaw”) and then proceed to the rest of the body, resulting in bone fractures, inability to swallow, blood clots, and, in 10-20% of cases, a painful and gruesome death. In 2013, tetanus was responsible for approximately 59,000 deaths worldwide, down from 356,000 in 1990.
Acute tetanus is treated by using tetanus immune globulin (antitoxin), tetanus vaccine (toxoid), and antibiotics. Tetanus is prevented, very simply, with safe and effective tetanus vaccines.
Diphtheria is caused by the bacterium Corynebacterium diphtheriae and is transmitted by infected persons. The disease begins like so many other common childhood infections — sore throat, fever, swollen glands, and weakness — but rapidly progresses with the formation of a thick, adherent grey coating (pseudomembrane) on the back of the throat and nasal passages, blocking the airway and making breathing very difficult, if not impossible. In complicated cases, the heart (myocarditis) and nervous system (peripheral neuropathy) are involved.
Like tetanus, diphtheria is also a toxin-mediated disease. Therefore, diphtheria immune globulin (antitoxin) is the primary treatment; antibiotics and airway support are also both critically important. Diphtheria is most dangerous in children under five years old, with a fatality rate of 20%. Worldwide, there were about 2,900 deaths from diphtheria in 2010, down from about 6,900 in 1990. Vaccines are extremely safe and effective in preventing diphtheria, with local outbreaks occurring only in unvaccinated individuals and communities. In 1998, politics and poverty conspired to lead an outbreak in the former republics of the U.S.S.R. 200,000 cases of diphtheria and 5,000 deaths were reported by the International Red Cross.
Pertussis or whooping cough is caused by the highly contagious bacterium Bordetella pertussis. The infection begins like a common cold with nasal congestion, mild cough, and fever. After a few days, the fever resolves and the congestion improves, but the cough gets worse. Much worse. The “staccato” cough that characterizes the illness is so severe that it literally takes the breath away: lots of coughing out with no breaths in. Eventually, when all the air has been expelled from the lungs (and perhaps a rib or two is broken), the defining “whooping” sound occurs as the larynx finally relaxes and a deep, life-saving breath is taken. Kind of like this:
That video is very hard to watch, isn’t it? Brutal. The cough doesn’t last for a few days, or linger for a week or two. No. It goes on for one hundred days (thus, pertussis is also known as “100 day cough”). That’s 10 weeks. Complications include apnea (not breathing, which is a bad thing) in young infants, pneumonia, brain injury, seizures, and death. Treating with antibiotics renders one non-contagious after 5 days but does not alter or shorten the clinical course.
Worldwide, it is estimated that nearly 50 million people are infected with pertussis every year. Approximately 61,000 died from pertussis in 2013, which is less than the 138,000 who died in 1990. Wherever herd immunity has decreased on this planet — most recently in Europe in 2009, Vermont and Washington in 2012, and California in 2010, 2012, and 2014 — pertussis has found its niche and prospered, to the detriment of humans and especially children.
Treating pertussis with antibiotics merely renders the victim not contagious after five days; it doesn’t alter the course or duration of the illness in any way. The vaccine is given together with the tetanus and diphtheria components (note that all three are bacterial infections) as the DTaP in infancy and childhood and the TdaP in adolescents (11-12 years) and adults. Pertussis vaccine is not as effective as one would hope and, like tetanus and diphtheria, immunity wanes over time. Children and adults who are properly immunized can still get pertussis, though it is clear that the clinical course and duration are not as severe as those who are unvaccinated.
Anyone who says it’s better (and safer) to get the natural infection instead of getting the vaccine never heard of tetanus or diphtheria or pertussis. Unlike measles, mumps, or chickenpox, infection does not confer immunity to one who gets sick with them. People who insist on not vaccinating their children or themselves should read this blog post again (and watch the video again), lest they be taken as fools and never listened to as credible people ever again.
The vaccine schedule for tetanus, diphtheria, and pertussis is straightforward:
- The primary series, using DTaP (the “a” refers to the acellular type of pertussis vaccine) at ages 2, 4, 6, 15-18 months and 4-6 years of age.
- The adolescent booster dose, using TdaP at age 11-12 years.
- Adult booster doses, using Td every 10 years.
- Adults who have never received the pertussis component after the primary series was completed (kindergarten age) should receive a one-time dose of Tdap.
- Pregnant women should receive a dose of TdaP in the third trimester of each pregnancy. Fathers who have never received a Tdap should also get one during the pregnancy (preferably) or right after the baby is born.
- Patients with clean minor wounds do not require tetanus shots unless immunizations are not up-to-date (as described above).
- Patients with wounds contaminated with dirt, soil, feces, saliva; puncture wounds; burns; animal bites; and crushing injuries need a tetanus shot (Td or TdaP) and tetanus immune globulin (TIG), if the last tetanus vaccine was given more than five years ago, or if the immunization status is unknown.
So I ask again: When was your last tetanus shot?