With certain exceptions, US adults could safely forego tetanus and diphtheria booster vaccination—if uptake of childhood vaccines stays high, an Oregon Health & Science University–led research team wrote yesterday in Clinical Microbiology Reviews.
Discontinuing the 10-year doses could save about $1 billion each year, said the researchers, who compared the impact of the tetanus and diphtheria vaccination programs to that of other routine childhood vaccines, reviewed childhood vaccination programs in France and England, and proposed revisions to the adult booster vaccination schedule.
While diphtheria is highly contagious, the community is broadly protected through childhood vaccination, and “Tetanus is unique among vaccine-preventable diseases because it is not transmitted from person to person; therefore, vaccination provides important individual protection but does not impact the risk for a community at large,” the study authors wrote.
‘More likely to be struck by lightning’
The current US vaccination schedule calls for giving children five doses of the Tdap (diphtheria, tetanus, and pertussis [whooping cough]) vaccine by age 7, adolescents one dose at age 11 or 12, and adults one dose every 10 years. Current US childhood vaccine coverage is 95%.
Despite lacking the technological advances of today, these medical interventions represent two of the most successful vaccines ever developed.
Studies the team conducted in 2016 and 2020 suggested that the vaccines generate at least 30 years of immunity against the life-threatening infections, far beyond the current 10-year booster recommendations and previous recommendations for even more frequent boosters (eg, every 3 years in 1955).
In addition, childhood vaccination against tetanus and diphtheria have achieved roughly 95% and 99.9% reductions in those diseases, similar to those of other routine pediatric vaccines such as measles (99.9%), mumps (97.6%), and rubella (99.9%), the researchers said.
“Despite lacking the technological advances of today, these medical interventions represent two of the most successful vaccines ever developed, as indicated by the incidence of disease falling to less than one case of tetanus per 10 million person-years and approximately one case of diphtheria per 1 billion person-years in the U.S. population,” they wrote.
First author Mark Slifka, PhD, of Oregon Health & Science University, said in a university news release that childhood vaccination has ensured that diphtheria and tetanus are “incredibly rare” today. “In fact, you’re 10 to 1,000 times more likely to be struck by lightning than to be diagnosed with tetanus and diphtheria in the United States,” he said.
Closer alignment with WHO guidelines
Like the United States, France recommends tetanus and diphtheria booster vaccines for adults. But the United Kingdom hasn’t recommended them for anyone older than 14 since the 1950s, except for pregnant women or for those with tetanus-prone wounds.
These findings indicate that after completing the childhood vaccination series, decennial booster vaccinations may no longer be needed to maintain protective immunity in the general population.
Yet the investigators found that the United Kingdom had a slightly lower rate of tetanus and diphtheria infection and that population immunity remained strong even through a 2022 outbreak of 73 imported diphtheria cases among immigrants seeking asylum.
“Remarkably, despite this proportionally large influx of imported diphtheria cases, there was no evidence of transmission reported among other asylum seekers who arrived by other routes or among staff or health care workers,” the authors wrote.
The authors caution that adult boosters should still be considered for emergency use in cases involving susceptible wounds, pregnant women, travelers to areas endemic for diphtheria, and anyone who didn’t complete the childhood vaccine series.
“These findings indicate that after completing the childhood vaccination series, decennial booster vaccinations may no longer be needed to maintain protective immunity in the general population,” the researchers wrote, adding that the move would more closely align US recommendations with the World Health Organization (WHO) guidelines, which haven’t recommended adult boosters against tetanus or diphtheria since 2017.