A case of diphtheria was detected last Friday in a patient hospitalized at the Dunkirk hospital centre in northern France. The regional health agency said the bacterial disease has become rare in France thanks to mandatory infant vaccination, which is followed by several booster doses throughout life.
Diphtheria is not the only disease that vaccination has pushed to the margins in France. Diseases such as smallpox, polio, tetanus, measles and rubella have all been eradicated or nearly eliminated through immunisation programmes.
Diphtheria still surfaces occasionally
Diphtheria is a serious bacterial infection spread through respiratory droplets. It causes false membranes at the back of the throat that can lead to death by asphyxiation, according to the Institut Pasteur. Skin infections are more common and usually less severe. Treatment involves administering a diphtheria antitoxin and antibiotics as quickly as possible.
The disease typically causes a sore throat, fever and swelling of the neck, with an incubation period of two to five days. It spreads mainly through close contact with an infected person, though it can also pass through contact with skin wounds or, more rarely, contaminated objects.
Good vaccine coverage means the disease is well controlled in France, though not fully eradicated. The Institut Pasteur said 69 cases of toxin-producing C. diphtheriae infection were recorded between 2011 and 2020, all either imported or detected in overseas France among people who were unvaccinated or only partly vaccinated. Most were cutaneous infections and none proved fatal. Over the same period, 84 cases of toxin-producing C. ulcerans infection were reported in mainland France, some of which were fatal. Without a vaccine, diphtheria can kill up to 30% of those infected, the institute said.
Smallpox: the greatest success of modern medicine
Smallpox is an extremely contagious viral disease marked by high fever and pustules across the body. According to Montpellier University Hospital, the first cases date back to 10,000 BC, and epidemics returned every ten to fifteen years in a given area, killing between a quarter and a third of those infected each time.
After a 12 to 14 day incubation period, patients developed fever, headaches, exhaustion and muscle pain, followed by a rash that spread from the mouth and face to the trunk and lower limbs before forming pustules and scabs.
English physician Edward Jenner developed the smallpox vaccine in 1796, and the first vaccinations took place in France three years later. The hospital said mortality from smallpox fell from 10% to 1% within a few years in countries that adopted vaccination. The last naturally occurring case worldwide was recorded in Somalia in 1977, and the World Health Organization officially declared the disease eradicated in 1980. The NGO One notes that smallpox remains the only infectious disease to have achieved that distinction.
Polio: once the world's most feared disease
Poliomyelitis is a highly contagious viral infection that particularly affects children under five. It spreads mainly through contaminated food or water or by the faecal-oral route, according to One, which says polio had become the most feared disease in the world by the end of the 19th century.
The illness begins with flu-like symptoms such as fever, fatigue and headaches, sometimes with vomiting, neck stiffness and limb pain. The virus multiplies in the intestine before invading the nervous system, and can cause paralysis of the legs or breathing muscles within hours. One in 200 infections leads to irreversible paralysis.
Dr Jonas Salk developed the first effective polio vaccine in the 1950s, followed by a second vaccine from Dr Albert Sabin. Before mass vaccination, polio affected more than 600,000 children a year worldwide. Today it is more than 99% eradicated. The Institut Pasteur said wild type 2 strains have not circulated since 1999, and no case linked to type 3 has been reported since November 2012. Only wild type 1 still circulates, mainly in Afghanistan and Pakistan, now causing a few hundred cases a year.
Tetanus cannot be eradicated
Tetanus is caused by spores of the bacterium Clostridium tetani, which the World Health Organization says are found everywhere in the environment, including soil, ash, human and animal intestines and excrement, and on rusty tools such as nails, needles and barbed wire. It cannot be transmitted between people and can be prevented through vaccination. The most frequent cases occur in unvaccinated newborns and pregnant women.
Incubation lasts between three and 21 days, with most cases appearing within 14 days. Symptoms include jaw cramps or difficulty opening the mouth, back spasms, sudden painful muscle spasms often triggered by noise, difficulty swallowing, fever, sweating and changes in blood pressure or heart rate.
Despite widespread vaccination, tetanus has not disappeared in France, where a small number of cases are still declared each year: 28 in 2001, 17 in 2005, eight in 2009, ten in 2013 and four in 2017, mostly among older people, according to the site vaccination-info-service. Because the bacterial source in soil is inexhaustible, the site said eradicating tetanus is impossible. Worldwide, deaths of newborns from tetanus have fallen 97% since 1988, when more than 700,000 newborns died from the disease within their first month of life, according to One.
Measles remains a major infectious threat
Measles is an extremely contagious viral disease spread through the air when an infected person breathes, coughs or sneezes, and can cause severe complications or death, the World Health Organization said. It can affect anyone but is more common in children.
The virus infects the respiratory tract before spreading through the body, producing a skin rash preceded by a runny nose, conjunctivitis and cough, along with very high fever and severe fatigue.
In 1980, before vaccination became widespread, measles was estimated to kill 2.6 million people a year worldwide, and France recorded more than 600,000 cases annually. According to the latest data, published in July, 109 measles cases have been reported since the start of the year, compared with 752 over the same period in 2025. Santé publique France said measles remains one of the world's biggest infectious scourges. The Elsan hospital group said vaccine coverage in France needs to reach 95% with two doses to eliminate the disease, and currently stands at around 90%.
Rubella no longer circulates actively in France
Rubella is an acute, contagious viral infection caused by an RNA virus known as rubivirus. It spreads easily through coughing or sneezing or via contaminated objects, and can pass to a fetus through the placenta in pregnant women.
It causes fever and a skin rash, though the site Ameli said it often goes unnoticed. The illness can be serious when it occurs in an unvaccinated pregnant woman before the 18th week of pregnancy, since it can cause abnormalities in the pregnancy and the baby's development.
Rubella is subject to a World Health Organization elimination plan, and a combined vaccine against measles, mumps and rubella offers protection. Ameli said no rubella cases were declared in France in 2020 or 2021. Thanks to vaccination, which has been mandatory for children born from 2018 onward, France's health insurance body said the rubella virus no longer circulates actively in the country.
