How safe is pentavalent vaccine, ask paediatricians, experts

As the deadline for the implementation of the five-in-one pentavalent vaccine in Tamil Nadu and Kerala nears, the debate on the pros and cons of introducing such a project is picking up momentum.

The Centre decided to start, on a pilot basis, introduction of the pentavalent vaccine (DPT, HiB, Hepatitis B) from September in the two States with better vaccination coverage and good monitoring systems in the country. The results of this project would determine if the country could shift entirely to the pentavalent vaccine.

However, some paediatricians and vaccine experts, have questions about the efficacy of the pentavalent vaccine and have expressed concerns about Adverse Events Following Immunisation (AEFI), based on the reports from neighbouring nations that have already tried out the pentavalent vaccine.

K.V.Babu, a Kerala-based physician who filed an RTI application with the Union Health Ministry, pointed out that the National Advisory Group on Immunisation (NTAGI) in its meeting on August 26, 2010, recorded concerns about AEFIs. In fact, it has been noted that since there is not enough data on vaccine safety, it was specifically recommended that the vaccine should be initiated in the State with better AEFI monitoring and surveillance system.

AEFIs were reportedly noticed while using the vaccine in Sri Lanka, Bhutan, and Pakistan. NTAGI members noted that vaccination in Sri Lanka and Bhutan was stopped following these incidents, but also recorded that after investigations, Sri Lanka resumed pentavalent vaccination in 2010 and Bhutan too has taken the decision to resume it.

Sarada Suresh, former director, Institute of Child Health, who is currently a technical advisor with the State Rural Health Mission, says the problem is that when AEFIs are reported, the tendency is to stop the vaccination programme. “This would mean that children would lose protection against all five vaccines, because they are given in combination,” she said. Also, it is a source of worry that the government would be using the Whole Cell vaccine for Pertussis (in DPT) instead of the more efficient acellular vaccine which has fewer reactions, but costs more, she added. Some members had reservations about including the HiB vaccine in the pentavalent combination, but recommended that it may be introduced as a standalone vaccine. “The basic issue that we have is that there has been no impact study for HiB. The ideal place to test this HiB would be in Delhi, where the burden of disease (pneumonia) is high, not in Tamil Nadu or Kerala with significantly lower disease burden,” Dr. Babu said.

The big question that Rex Sargunam, Chennai-based paediatrician who also served as director of the ICH, poses is about costs. The costs are much higher (though much is saved in logistics, plastics and sharps), thus affecting the scalability of the project, and ultimately, would result in limiting the pentavalent vaccine to certain States or groups alone, he said.

Cost is not of immediate concern, officials of the Tamil Nadu Public Health department said.

In its pilot phase, the vaccines are being supplied by UNICEF. There is enough literature worldwide establishing the benefits of the pentavalent vaccine which is being used in several countries.

K. Vanaja, joint director, Immunisation, said that the original deadline of September might not be met.

It is likely that the programme would now start only in October, because of a delay in arrival of the vaccine.

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