Pentavalent Update 5 November, 2009 - Except for one case, the deaths of eight babies who received the pentavalent vaccine were “coincidental” according to the preliminary findings by experts from the World Health Organisation (WHO).

“The only case that had a weak link to the vaccine was the seven weeks old baby who was referred from Gidakom hospital on September 10,” said the public health director, Dr Ugen Dophu, after the preliminary findings were shared with the media yesterday afternoon. The experts were not present at the briefing. “The child didn’t have any existing disease or any other health problems and the only new thing given was the vaccine. That’s the only link.”

In case of the eight infant deaths that died from Meningo-encephalitis, an infection that causes inflammation of the brain and meninges, the membranes and fluid surrounding the brain and spinal cord, the preliminary report ruled out any connection to the vaccine. “Meningo-encephalitis is caused by a live virus and the pentavalent vaccine does not contain any live virus,” said the public health director.

The investigation found a total of nine deaths among infants less than six months old who had received the vaccine. Besides the first five deaths, three babies in Sipsoo who were seven, ten and 11 weeks old and a six-week old baby in Paro died after receiving the vaccine.

“The deaths of the eight babies were not related to the vaccine because, according to their medical history with the hospitals, they all had other medical illnesses like respiratory problems,” said Dr Ugen Dophu.

It is for the first time in the world that an incidence of meningo-encephalitis was reported in pentavalent vaccine. “The same batch of vaccines in Bhutan has also been introduced in Gambia in western Africa and São Tomé a Portuguese-speaking island nation in the Gulf of Guinea and they haven’t reported any such cases,” said Dr Ugyen Dophu. “No country has ever reported this and it’s not even written in medical literature,” he said adding that Sri Lanka’s adverse effects following immunisation (AEFI) of hypotonic-hypo responsive episode (HHE) after the vaccine in December last year has been documented. Even in Sri Lanka WHO’s and an independent panel’s investigation ruled out the vaccine as the cause of deaths.”

The experts also checked Bhutan’s history of meningo-encephalitis reported cases. They found that Bhutan had the problem with the disease even before the vaccine was introduced. “In the first half of 2009, there were 352 cases reported in all age groups out of which, 89 were reported in children below five years,” said Dr Ugen Dophu.

One of the main recommendations is to study the cause of meningo-encephalitis in Bhutan and to take measures to prevent the disease. It was also recommended to keep monitoring and recording infant deaths regularly and if necessary to send a team to investigate every death. Last year there were 19 cases reported in children of which six died.

The experts have also recommended that until Bhutan gets all lab reports, the health ministry should continue with the tetravalent vaccine, said the public health director.

Samples of Bhutan’s pentavalent vaccine will be sent to an internationally recognised independent laboratory recommended by WHO to test its quality. “Once we receive a list of the laboratories and dispatch the samples, it would take about three weeks to get the analysis report,” said Dr Ugen Dophu. Health officials will also monitor cases of meningo-encephalitis in infants for the next few months to see changes in infant mortality.

According to the preliminary report, the experts found no programme error in the cold chain of the vaccine, which involves the transportation of the vaccines from the factory to Bhutan and its distribution to health centers.

The director said that the health ministry would continue to investigate until it is confident that the vaccine did not cause the deaths. “I think no country or ministry would want to introduce a vaccine that would cause deaths,” he said. “The idea is to prevent diseases.”