GSK gears up to make 1 b doses by 2021

Pharma major GlaxoSmithKline (GSK) is gearing up to manufacture one billion doses of a potential Covid-19 vaccine candidate by 2021, the company announced on Wednesday.

In a global virtual briefing, Emmanuel Hanon, Head of Research and Development, GSK Vaccines, said GSK has collaborated with Sanofi, Innovax, Clover Biopharmaceuticals and University of Queensland, among other partners, to develop multiple potential adjuvanted vaccine technology candidates. The company hopes to get a breakthrough with at least one of these multiple candidates by the second half of 2021. GSK adjuvant technology was proven in pandemic influenza H1N1 (or swine flu) where less antigen was needed and more vaccine doses were made available.

What is an antigen?

An antigen is a molecular structure that can be recognised by the immune system. It stimulates an immune response and helps in producing antibodies that help the person fight the infection. An adjuvant is a substance added to the antigen to boost the immune response.

An adjuvanted vaccine therefore leads to an enhanced immune response of the body against a potential virus attack. This also means that less antigen is needed during production. “This is particularly important during a pandemic as more vaccine doses can be available to protect more people around the world,” Hanon explained.

Manufacturing capacity

While GSK has a large capacity to manufacture the adjuvants, Sanofi has a large capacity to manufacture antigens, said Hanon. Addition of adjuvants drastically reduces the need for more antigens and also produces a high-quality immune response, which has led to partnership between the British and French pharma majors to produce potential vaccine candidates.

Russell Thirsk, Head of Belgium Operations, GSK Vaccines, said the company has 13 manufacturing sites across the globe that produce 700 million sterile vaccine containers (which contain multiple vaccine doses) annually and that to produce a billion Covid-19 doses, an additional capacity of 100 million sterile containers will need to be added.

“We can easily accommodate this increase in output by adding an additional working shift of staff to the existing manufacturing operations. There is also no need for additional capital investment for this,” said Thirsk.

“There should be credible R&D to also investigate if a pan-coronavirus vaccine holds promise, as structural biology of all the three viruses (MERS, SARS) belonging to the same family shares a part of a similar antigen structure,” Hanon said.