A Lesson for the Measles Epidemic in the United States: Vaccines Do not Protect You, They Protect Everyone Around You

Washington has been at the heart of the country's worst measles epidemic for more than 20 years. The disease is spreading rapidly among an increasing number of people who have chosen not to be vaccinated or their children. But Brandon Dionne, who studies infectious diseases at Northeastern University, says the choice not to vaccinate also affects another population: people whose immune system prevents them from being vaccinated.

Measles, a highly contagious respiratory infection, was considered eliminated in the United States through widespread vaccinations often given to children when they were about a year old, Dionne said.

"It's incredibly contagious," said Dionne, badistant clinical professor in pharmacy and health sciences. "It can spread by air, so it's not necessary to contact a person with measles to catch it; just stay in the same room as someone else." one another. "

Because the infection is so contagious, 90-95% of the population must be vaccinated to get what immunologists call "group immunity." Dionne describes this as the time when a high enough percentage of a community is immune to a disease to protect even those who are not vaccinated.

And "collective immunity" is the goal of a disease like measles.

"Most healthy people can tolerate measles," Dionne said. "The real risk is for groups of people who can not, either because their immune system is compromised or their health conditions may prevent them from being vaccinated."

According to Dionne, contracting measles can be fatal for such populations.

Meanwhile, a movement against vaccinations, sparked by the discredited theory that vaccines cause autism, is growing.

Dionne says that the problem with a measles vaccine in particular is that he has become "a victim of his own success".

"The vaccine has been so effective against measles that very few people get the disease," he says.

The scarcity of the disease, combined with the circulation of "false information" about the misdeeds of vaccines (including misconceptions that vaccines are useless due to modern hygiene or that vaccinating multiple children can overloading their immune system) means that more and more people are weighing the risks and choosing not to vaccinate themselves or their children, says Dionne.

"But the real calculation of the risk to take into account is the following: even if you think you can not benefit from vaccines, there are others who can not protect themselves and who can benefit from your vaccination," says -he. "That's the main reason I do what I do."

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Northeast University