As multiple research teams take a shot at developing a vaccine to fight Covid-19, the scientific universe is abuzz with discussions on the many features of these products, including whether a one-dose vaccine would do or a two-dose formulation is needed.

But injecting some timelines into the discussion, experts point out that there’s a long road ahead in terms of trials and distribution challenges.

Concerned about the equitable distribution of the vaccine, as and when there is one, the Director General of World Health Organisation, Dr Tedros Adhanom Ghebreyesus, said they had developed an “allocation framework” to deal with the problem. But the most important thing in ensuring access is “political commitment”, he said, urging countries and leaders to contribute to make the vaccine a “global public good”.

There’s a long way to go and large-scale real world trials are needed, said Dr Michael Ryan, Executive Director of the WHO Health Emergencies Programme, during a briefing on the day AstraZeneca and Oxford University released interim data on their vaccine candidate showing positive results in terms of strong antibody and T-cell responses.

Outlining details for a largescale multi-region studies, AstraZeneca Chief Executive Pascal Soriot said they were racing ahead with late-stage Phase II/III clinical trials in the UK, Brazil, South Africa and the US, possibly by the end of the month, he said. So by the time the trials end, there would be a large database on the safety of the vaccine, he said.

AZ was on track to meet its projected September timeline on the vaccine, he said, as production would run concurrent to the trials. But this could take a couple of more months, he added, depending on the infection rate or people with the virus in the region.

India trial

“We will be doing a study in India. It’s a big country and there is a lot of infection,” Soriot told BusinessLine . The company has multiple distribution alliances for the prospective vaccine. In India, it has an alliance with Serum Institute which is in the process of getting regulatory approvals to get the trials and manufacturing process started.

Giving details on the Oxford University-led trials, the company said interim data from the ongoing Phase I/II COV001 trial showed “AZD1222 was tolerated and generated robust immune responses against the SARS-CoV-2 virus in all evaluated participants.” The data was published in The Lancet .

Candidates in pipeline

On the same day, BioNTech SE and Pfizer Inc also announced initial data from their ongoing German Phase 1/2 trial that was part of their global mRNA-based vaccine programme against SARS-CoV-2. “The preliminary data indicate that our mRNA-based vaccine was able to stimulate antibody as well as T-cell responses at remarkably low dose levels. We believe both may play an important role in achieving effective clearance of a pathogen such as SARS-CoV-2,” said Özlem Türeci, Chief Medical Oofficer and Co-founder of BioNTech. The data from a preprint version was undergoing scientific peer-review for potential publication, they said.

There are over 160 vaccine candidates being developed to tackle Covid, and 24 of them are in different stages of being tried on humans, the WHO said. This even as Russia claims to have a ready vaccine.