As communities, states, and countries begin to reopen, the question top-of-mind for many is when will a vaccine, or other treatment, be available? Many hold out hope that a vaccine will be the magic bullet. It’s not that simple.
Although there is still considerable uncertainty about the duration of protective immunity developed in the population after COVID-19 infection, and even the feasibility of generating an effective vaccine with any long-term effect, a large number of researchers and companies have initiated a diverse selection of vaccine projects, using a broad mix of established and innovative technologies. Development for COVID-19 has been accelerated considerably by acquired knowledge developed during the generation of candidate vaccines for related SARS and MERS coronaviruses, as well as recent research into Ebola vaccines.
Ten COVID-19 vaccine candidates are currently in clinical trials (as of 4 June). These are listed in the below, in approximate descending order of advancement, taking into account scale of development and expected reporting dates. So far, one has entered Phase II/III development, two are in Phase II, and several more are in Phase I/II and Phase I. In addition, some selected high-profile preclinical-stage projects have also been listed. The success of any of these will depend on safety, level of immunogenicity, and duration of protection.
Five vaccine candidates are currently being developed in China, including those from CanSino and Sinovac. China itself has a chequered history in biopharmaceutical clinical development, but this is a unique and watershed opportunity to prove itself on the world stage. While data on its candidates remain relatively scant at this stage, China may indeed succeed in becoming first-to-market in this space, or at least provide a critical option on the global stage for vaccines against COVID-19 in 2021.
In the absence of a vaccine, effective therapeutics for COVID-19 and its complications are urgently being sought to help mitigate the most serious consequences of infection and to reduce the duration of virus shedding and infectivity. This is especially important since the timeline for approval of a repurposed known medicine would be much shorter than that for a vaccine, since safety would already be established. There has been a major research effort worldwide, with hundreds of trials and investigations having been initiated for a wide range of existing and novel compounds, with varied degrees of success. Medicines that are currently receiving EUAs are highly likely to be superseded by more effective products – some with similar mechanisms – as results from controlled trials become available.
We expect the most dramatic developments in the research and development (R&D) landscape here not to come from remdesivir, hydroxychloroquine, or other repurposed treatments, although we do see a critical role for existing treatments being repositioned to deal with the various effects of COVID-19 – such as the promising data for interleukin-6 [IL-6] therapies. Instead, while data remain very scant because of the early stages of development, we are more interested in the development of “antibody cocktails” such as those being developed at Regeneron (US) and Vir (US).