Final answer:
The 1998 study initially suggesting a link between the MMR vaccine and autism was retracted due to significant flaws. Subsequent research has consistently found no causal relationship between the vaccine and autism. Diseases like measles, mumps, and rubella are rare due to effective vaccination programs that maintain herd immunity.
Step-by-step explanation:
The study conducted in 1998 regarding the link between the measles, mumps, rubella vaccine (MMR) and autism concluded that there was a possible link between the MMR vaccine and autism. However, this study has been widely discredited and its findings retracted due to serious procedural errors, undisclosed financial conflicts of interest, and ethical violations. It is important to note that extensive research has since been conducted and has found no link between the MMR vaccine and autism.
Elena might be concerned about the increase in the number of children with autism and the cases where symptoms of autism appeared after MMR vaccination. Still, correlation does not imply causation. The timing of the onset of autism symptoms and the MMR vaccination are coincidental, as autism symptoms typically become noticeable at the age children receive this vaccine.
The reasons diseases like measles, polio, and mumps are rare these days are largely due to the success of vaccination programs. Vaccinations continue to be important because they protect not only individuals but also communities by maintaining herd immunity, which helps prevent outbreaks of these diseases that still have the potential to cause harm.