Experts warn global Covid vaccine could take until late 2023

DESPITE global efforts to develop and deploy a successful Covid-19 vaccine to end the current pandemic, analysis of vaccine development and manufacture scaleup point to a Covid-19 vaccine achieving global coverage in late 2023. While vaccine efforts continue, it is recommended that other mechanisms should be employed to help manage the crisis.

These findings were highlighted by two recent reports, contributed to by IChemE members, which investigated the delivery of a successful vaccine. One report, released by the Center for Global Development (CGD), uses modelling and expert opinion to estimate timelines and the probabilities for developing and producing a successful vaccine. The second other report, released by the Royal Society convened group DELVE (Data Evaluation and Learning for Viral Epidemics), focuses on the challenges involved in vaccine delivery, from development to deployment.

Highlighting challenges

Efforts to develop a Covid-19 vaccine are occurring at unprecedented speed. According to DELVE, there are more than 200 vaccine candidates under development and initial results from large-scale trials are expected soon. DELVE’s report, SARS-CoV-2 Vaccine Development & Implementation; Scenarios, Options, Key Decisions, highlights the key challenges involved, the impact of those challenges, and future strategies to mitigate them.

Multidisciplinary group DELVE was convened to support a data-driven learning from the approaches which different countries are employing to manage the pandemic.

Capacity challenge

Overall, the challenges facing manufacturing are caused by the urgency and scale of demand for a new vaccine to a previously unknown disease, says the report. An “enormous” challenge facing Covid-19 vaccine manufacture is achieving the scale required to meet the demand of a global immunisation programme.

Once an effective vaccine is identified it will have to be manufactured at high enough capacity to combat the pandemic while manufacture of existing vaccines continues. Furthermore, the nature of the vaccine could have implications for capacity requirements. For example, if immunity is short-lived and boosters are needed, capacity will be needed to extend coverage while also maintaining immunity in existing recipients.

The report highlights that while substantial amounts of global manufacturing capacity can be repurposed across vaccines, this is not possible in all cases. In the UK, where capacity is constrained, short-term disposable technology has been employed to initiate production in repurposed existing facilities.

DELVE also recognises the importance of financial incentives for accelerating both vaccine development and achieving manufacturing capacity. Financial incentives such as “pull funding” like advanced market commitments (AMCs) have been employed. AMCs are purchase agreements that can be used to guarantee price and quantity of vaccines purchased before trial results are known and in advance of licensing. The UK, for example, has reportedly made forward purchasing deals for more than 300m vaccine doses – potentially enough for almost five doses per person, according to the report. The US, EU, and Japan have also secured hundreds of millions of doses.

Purchase guarantees at a fixed price incentivise and de-risk vaccine development and investment in manufacturing capacity.

Direct investment in capacity has also occurred. The UK Government has worked to increase capacity, for example by investing in the Vaccines Manufacturing and Innovation Centre (VMIC), the UK’s first strategic vaccine development and advanced manufacturing facility. It has also purchased a facility in Essex, UK from Benchmark Vaccines, a contract manufacturing company focussed on animal health vaccines, which it will upgrade for Covid-19 vaccine production.

For managing future outbreaks, DELVE recommends maintaining surge vaccine manufacturing capacity to enable accelerated deployment. Surge capacity refers to increased capacity available during mass casualty situations and disasters. Maintaining surge vaccine manufacturing capacity is “crucial” for rapid-response vaccine production, says the report.

It is worth noting that these investments have been made based on assumptions about the most likely type of vaccine to be developed.

According to DELVE, the health crisis has seen governments, non-governmental organisations (NGOs) and industry make unprecedented levels of investments to accelerate vaccine development and manufacture. Beyond individual efforts it encourages coordinated upscale of manufacture to ensure sufficient capacity, as well as reduce the likelihood of “vaccine nationalism” and ensure the availability of affordable global vaccine supplies, thus reducing the likelihood of future global outbreaks.

DELVE notes that investment as well as scientific innovations achieved during the pandemic will benefit the development of future vaccines.

Timothy Clayton, an IChemE member who contributed to the DELVE report, said: “The vaccine requirement is beyond anything ever attempted for a single disease and we need a truly international effort to control Covid-19. This is going to need significant effort and investment to build an unprecedented pharmaceutical supply chain with extra manufacturing capacity from glass supply to vaccine manufacture, with matching storage and distribution infrastructure. We also need to continue making all necessary pharmaceutical products in parallel.”

The joint IChemE and International Society for Pharmaceutical Engineering (ISPE) UK Affiliate team contributed to the DELVE report. ISPE is an organisation working to lead advancement throughout the pharmaceutical lifecycle. IChemE’s participation was through its Covid-19 Response Team.

Projecting success

Entitled COVID-19 Vaccine Predictions: Using Mathematical Modelling and Expert Opinions to Estimate Timelines and Probabilities of Success of Covid-19 Vaccines, CGD’s report seeks to offer projections which can inform the decision-making of the public and private sector.

According to Adrian La Porta, CGD report co-author and member of IChemE’s Covid-19 Response Team, CGD set out to model vaccine research and manufacturing because it recognised that individual research groups’ announcements about progress could not give a holistic picture of when a vaccine might be available.

He added: “Biochemical engineers’ knowledge of vaccine processing underpins the predictions of the time from vaccine approval to having enough doses for target populations.”

La Porta has been a member of the Response Team since its inception, and has contributed to the personal protective equipment (PPE) decontamination work group and the therapeutics work group. 

Based on information provided by experts, the report’s model projects that the probability that a stringent regulator approves at least one vaccine in 2020 is less than 2%. This rises to 50% by April 2021, 85% by the end of 2021, and 98% by the end of 2022. The model predicts a <1% chance that no vaccine is approved from the current global portfolio, although pessimistic input pushes this to 20%.

CGD says scaleup and capacity models indicate that enough doses to vaccinate the entire global population may not be available until September 2023. However, sufficient production for healthcare workers is predicted for late 2021 to early 2022, and for at-risk/vulnerable groups 2–3 months after that.

The report highlights that first-generation vaccines are unlikely to be effective enough to end the pandemic, with experts projecting vaccine disease prevention of about 61% – too low to fully contain the virus.

Recognising that it will likely be more than 12 months before fully effective vaccines are developed, licensed and manufactured at scale to meet the needs of the whole population, CGD recommends using other public health measures to manage the outbreak. This includes continued investment in non-pharmacological measures such as social distancing, expansion of testing and contact tracing, and pushing for innovations in diagnostics and treatment which could help accelerate vaccine availability.