Funding for this research was provided by:
Swedish Foundation for International Cooperation in Research and Higher Education (SG 2015-5972)
-Training and Research Academic Collaboration
Styrelsen för Internationellt Utvecklingssamarbete (MFS)
Received: 1 March 2021
Accepted: 15 August 2021
First Online: 30 August 2021
: This study followed the ethical standards of the Helsinki declaration of 2008. Ethical approval was obtained from the VNCH Ethics Committee (reference number 812/QD-BVNTU, 23rd March 2017). Informed consent was given on an opt-out basis and all caregivers were informed about the study.
: Not applicable.
: There is no reported conflict of interest. All authors have agreed to participate in the paper.