Marcos López Hoyos
Scientific Director of the Valdecilla Health Research Institute (IDIVAL) and Professor of Immunology at the University of Cantabria
Does the press release accurately reflect the study?
"Perfectly. It summarises the type of epidemiological model used and the significance of the results in terms of public health. It also clearly states that they have used a conservative model with all the limitations of a heterogeneous population such as that of the United States."
Is the study of good quality? Are the conclusions supported by solid data?
"I am not familiar with the epidemiological method used, but I assume that in a prestigious journal such as JAMA it has been reviewed by expert statisticians and epidemiologists."
How does this work fit in with existing evidence?
"It fits with the epidemiological evidence of measles outbreaks occurring not only in the US but also in other countries."
Have the authors taken confounding factors into account? Are there any important limitations to consider?
"The limitations are clearly specified and consistent in the final section of the discussion."
What are the implications for the real world?
"It has clear implications as soon as a decline in vaccination rates and certain gaps in childhood vaccination are detected. This is a very relevant study, and the epidemiological model used demonstrates the evolution we will see if this decline in vaccination continues. A conservative model was used, with a measles virus replication rate of 12, when it is actually higher (around 20). This model shows that in 20 years, measles will become endemic again, which is a real tragedy.
The other three viruses (polio, diphtheria and rubella) do not behave in the same way, as their replication rate is lower than that of measles.
As the authors themselves point out, we do not know how vaccine fatigue will evolve after COVID-19, but this drop in vaccination rates and herd immunity protecting against these viral infections is very worrying.