Concerns over Oxford Covid-19 vaccine likely to impact export demand

Vaccine exports picked up last month; Serum shipped 11.9 mn to WHO-Gavi pool

Vaccine exports have been on the fast lane from India, but the concerns over adverse effects of Astra­Zeneca-Oxford jab may impact the momentum.
 
Till the first week of March, India has exported 48.1 million doses of vaccines to various countries – commercially, as grant, and for the Covax facility. Till the mid-February, the country had exported 16 million doses of Covid-19 vaccines, of which about 37 per cent were grants to neighbours for strategic reasons.
 
The data shared by the ministry of external affairs in the Lok Sabha shows around 15 per cent of the exports till March 4 are grants. Exports to the Covax facility has picked up in the past one month — with Serum Institute of India (SII) exporting 11.9 million doses of Covishield, the vaccine developed by AstraZeneca-Oxford, to the World Health Organization-Gavi led initiative to pool in vaccines and distribute among countries equitably. Most of the Covax exports have been to low-income countries like Kenya, Nigeria, according the data.
 
India started external supplies of made-in-India vaccines on January 20. The external affairs ministry said in a reply to the Lok Sabha that external supplies are done “factoring in domestic production, requirements of the national vaccination programme, and requests made for the made-in-India vaccines”. The supplies will continue in a phased manner, the minister said.

 
Covishield review
 
Several countries have fully or partially suspended the use of AstraZeneca-Oxford vaccines for fear of adverse events following vaccination like blood clots. These are mostly European nations like Denmark, Italy, and Austria among others. Thailand and Ireland, too, joined the list of nations suspending the use of the AstraZeneca vaccine as a precautionary measure. The European Medicines Agency is carrying out a review of the blood clot events. It has maintained that currently there is no indication that the vaccinations have caused these conditions.
 
In India, the Centre has decided to review the AstraZeneca-Oxford vaccine, which is made by the SII. SII said there was no impact on vaccine exports as of now. This is also because SII is primarily exporting to low- and medium-income countries and not the European belt. Teams from European regulators have visited SII’s Pune facility. Sources had indicated there was a possibility that SII could step in to compensate for the supply crunch that AstraZeneca was experiencing in Europe.

Reason behind adverse events
 
Dr Jacob John (pictured), senior virologist and former head of the departments of clinical virology and microbiology at Christian Medical College, Vellore, said vector-based vaccines have two immune responses by the body — one is against the vector itself which is irrelevant, the other is against the spike protein of the coronavirus, which is the relevant immunity.
 
We are creating an irrelevant immune response also. In the case of the AstraZeneca vaccine, it is the chimpanzee adenovirus (flu virus) vector that is used to deliver the genetic material of the coronavirus to the human cells. We have to see whether this irrelevant immune response is harmful or harmless. As far as Covid is concerned, the immune response to the vector is useless. Sputnik V is using a human adenovirus vector, against which many of us have been exposed.
 

Dr Jocob John

 
AstraZeneca is using a non-human adenovirus. This virus has been ‘castrated’ or made incapable of replication. However, it needs deeper investigation whether the immune response to this vector is an unexpected one in some people. The trial data has said it is harmless. Post trials, what we have seen so far are that there have been a few cases of auto-immune neurological response in some cases (not known whether linked to the vaccine). It is not known whe­ther this is related to vector immunity. Deeper investigation is needed to under­stand the immune response created by the vector.