Transparency
Declaration of funding
This letter was not funded.
Declaration of financial/other relationships
R.V.C. and H.D.d.B. have disclosed that they have provided lectures sponsored by Merck, Sharp & Dohme.
C.M.R.O. peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Acknowledgements
We would like to thank Professor Marcelo L. A. Torres for his constructive comments on our letter.