Police in the southern province of Dong Nai are investigating the death of a 4-month-boy who died Sunday night after receiving the Quinvaxem vaccine in the morning.
The boy was given the 5-in-1 shot at a commune medical center at 9 a.m. and fell into a coma at home four hours later.
His family rushed him to hospital where doctors put him on a ventilator and sent him to a bigger hospital. The baby died on the way.
The death came more than a week after a similar case in the northern province of Quang Ninh, which the health ministry said was not caused by the vaccine quality.
Quinvaxem is a WHO prequalified drug and has been distributed in Vietnam by Berna Biotech Korea Corp since 2010 under a national immunization program sponsored by the global vaccine alliance GAVI. It protects children from two months old against diphtheria, tetanus, whooping cough, hepatitis B, and Haemophilus influenza type B.
Babies are given the vaccine for free, but it has lost much of the public trust following the post-vaccination deaths of at least 22 since late 2012.
Supplies of alternatives such as the French-made Pentaxim, which costs around US$30 a shot, are limited.
Quinvaxem uses whole-cell preparations in its whooping cough component while costly alternatives use purified antigens, which are considered safer.
Vietnam provides around 5.5 million Quinvaxem shots every year and up to 200,000 of the alternatives, according to official data.