If you haven't had a tetanus booster shot in the past decade, your doctor may recommend getting one. Many people think of a tetanus shot as something you only need if you step on a rusty nail. Yet even in the absence of a puncture wound, this vaccine is recommended for all adults at least every 10 years. But why? A group of researchers recently questioned whether you need to repeat tetanus vaccines on a regular schedule.
What is a tetanus booster?
Booster shots are repeat vaccinations you receive after your first series of immunizations as a child. Protection from certain vaccines can wane over time, which is why doctors advise boosters. The tetanus vaccine is not just for tetanus though. It's bundled with a vaccine for diphtheria and sometimes one for pertussis (the bacteria that causes whooping cough).
What are tetanus and diphtheria?
Tetanus and diphtheria are rare but serious diseases that can cause severe complications in those infected.
Tetanus, sometimes known as "lockjaw," is an infection caused by a type of bacteria called Clostridium tetani. When this bacteria invades the body, it can produce a toxin that leads to painful muscle tightening and stiffness. In severe cases, it can lead to trouble breathing, seizures, and death. Tetanus does not spread from person to person. Usually it enters the body through contaminated breaks in the skin — stepping on a nail that has the bacteria on it, for example. There are about 30 reported cases of tetanus in the US each year. These cases almost always occur in adult patients who have never received a tetanus vaccine, or adults who have not been up to date on their 10-year booster shots.
Diphtheria is a bacterial infection caused by a type of bacteria called Corynebacterium diphtheriae. Diphtheria can cause a thick covering on the back of the throat and may lead to difficulty breathing, paralysis, or death. It typically spreads person-to-person. There have been fewer than five cases reported to the CDC in the past 10 years.
What are the current vaccine recommendations?
The Centers for Disease Control and Prevention (CDC) recommends tetanus vaccines for people of all ages. Adolescents and adults receive either the Td or Tdap vaccines. These vaccines protect over 95% of people from disease for approximately 10 years. Currently the CDC Advisory Committee on Immunization Practices recommends a booster shot every 10 years. Injury or wound management and pregnancy may affect this schedule.
What does the new study on tetanus boosters suggest?
A recent paper published in the journal Clinical Infectious Diseases suggested that tetanus and diphtheria booster vaccines are not necessary for adults who have completed their childhood vaccination series. This advice aligns with the current World Health Organization (WHO) recommendations. The researchers reviewed WHO data from 31 North American and European countries between 2001 and 2016, amounting to 11 billion person-years. (Person-years is a measurement that reflects the number of people in the study multiplied by years followed). After comparing the incidence of tetanus and diphtheria, they found no significant difference in disease rates in countries that require adults to receive booster shots compared with those that do not. Based on this, the authors suggest that childhood vaccination alone protects sufficiently against tetanus and diphtheria without booster shots.
So, what should you do?
The question of whether to have ongoing booster vaccines is more complicated than looking at frequency of a disease. The conclusions of this study focus on the lack of change in tetanus or diphtheria incidence rates among countries that routinely vaccinate children. However, other factors influence the number of cases, such as the overall amount of the bacteria in the environment, or wound management and hygiene measures.
Immunity from antibodies to tetanus and diphtheria may persist for many years. Over time, though, antibody levels decrease. We know that even if antibodies are present, low levels may not always be protective. Even though this study was well executed and raises some important questions, further studies are needed to examine whether a childhood vaccination series offers lifelong protection without repeated adult boosters.
Even though it happens rarely, people can still get tetanus and experience serious or deadly effects. There is no cure for tetanus, and no definitive proof that you will have lifelong immunity with childhood vaccinations alone. So for now, the CDC continues to recommend booster vaccines every 10 years to help your immune system protect against these infections. If you have questions about the tetanus and diphtheria vaccine, talk to your doctor.