A new study claims that pentavalent vaccine (PV), introduced in the country's immunisation programme six years ago, has doubled the deaths of children (soon after vaccination) as compared to DPT (Diphtheria-Pertussis- Tetanus) vaccine.
The study, published in the peer-reviewed journal, Wolters Kluwer Health’s journal, Medical Journal of Dr D Y Patel University, calls for a "rigorous review of the deaths following vaccination with PV."
The pentavalent is a combination of DPT vaccine and two more vaccines against Haemophilus Influenza type B (Hib) and Hepatitis B.
In December 2011, the vaccine was introduced in India's immunisation programme to replace DPT vaccine in a staged manner with a view to add protection against Hib and Hepatitis B, without increasing the number of injections given to infants.
At that time too, several public health experts had questioned the rationale behind introducing the vaccine and its adverse effects.
In their latest paper, Jacob Puliyel, head of Pediatrics, St Stephens Hospital in New Delhi, and V. Sreenivas, professor of Biostatistics at the All India Institute of Medical Sciences, say sporadic reports of "unexplained deaths" following immunisation with PV had been a matter of concern.
To investigate the issue, Puliyel, Sreenivas, and their colleagues undertook a study to find out if these deaths were merely coincidental or vaccine induced.
The authors obtained data of all deaths reported from April 2012 to May 2016 under the Right to Information Act. Data on deaths within 72 hours of administering DPT and PV from different states were used.
For the study, the authors say they assumed that all deaths within 72 hours of receiving DPT are "natural deaths". Using this figure as the baseline, they presumed that any increase in the number of deaths above this baseline among children receiving PV must be caused by the vaccine.
"If a state introduced PV in 2014, then data on DPT doses, PV doses, and deaths following vaccination were noted from that year on. This ensured that the deaths were all reported from the state using the same surveillance system," they said.
The analysis of the data provided by the government revealed that there were 237 deaths within 72 hours of administering the PV—twice the death rate among infants who received DPT vaccine.
Extrapolating the data, the authors say they estimated that vaccination of 26 million children each year in India would result in 122 additional deaths within 72 hours, due to the switch from DPT to PV.
"There are likely to be 7,020 to 8,190 deaths from PV each year if data from states with better reporting, namely Manipur and Chandigarh, are projected nationwide," their report says.
The authors, however, say while the study looks at the short-term increase in deaths (within three days of vaccination) it does not calculate the potential benefits of PV on infant mortality, for example by protection against lethal diseases like Haemophilus influenza.
In spite of the data presented in this paper (from a large cohort) the authors point out that the evidence is merely circumstantial and "not conclusive". "These findings of differential death rates between DPT and PV do call for further rigorous prospective population-based investigations," the study concludes.