When might we have vaccine or a treatment?
Hundreds of vaccines and treatments are in development
The remarkable global effort to produce a range of Covid-19 vaccines in parallel with developing new treatments – many of which are adapting proven medications for other diseases – is gathering pace.
The scale of scientific endeavour is unprecedented, not just in terms of finding a new vaccine, but in the level of co-operation between scientists; in quickly sharing results, data and critical genetic details; indications of variations in the form of what is known as SARS-CoV-2.
A rough assessment of timings on potential vaccines would suggest early optimism needs to be tempered and early 2021 is the most likely time one will become available - and only then in some countries.
Should we plan for a vaccine in 2021?
Trinity College Dublin immunologist Prof Luke O’Neill always refers to a horse-racing metaphor; you may be leading the Grand National and have just one fence to clear, and fall at the last hurdle.
The world has to face up to the fact that there may never be an effective vaccine. But O’Neill is quick to add that the ability to contain the novel virus through a combination of therapies is very likely – as was the case with Aids. Likewise, there are already treatments emerging that will act as a bridge to getting a vaccine in place.
The one discordant note undermining this tremendous team play is wealthy countries buying up treatments, as seen with the US recently purchasing all the next three months’ projected production of the drug remdesivir from US manufacturer Gilead: it cuts recovery times, though it is not yet clear if the drug improves survival rates.
There remains the risk that more wealthy countries aligned to powerful pharma companies will do the same when a vaccine emerges, and national interests will prevail over the need to give it to those requiring it most.
What is the emerging picture on leading vaccine candidates?
There are more than 145 candidate vaccines in development, with 17 in human trials. Some have been shown to generate a strong immune response in animals.
Those conducting vaccine trials are “chasing the disease around the world”, notably in Brazil and the US. Places where there are high levels of Covid-19 are the best to test efficacy and safety.
The extent of that research is likely to mean a range of vaccines of differing type and effectiveness will emerge – the first to come on stream might not be the magic bullet hoped for. But, given the whole world will need protection, a variety of vaccines from different sources is not such a bad thing.
Johnson & Johnson has indicated, for example, its vaccine appeared so promising in preclinical studies they were able to push up the start of testing in healthy volunteers to later this month.
The vaccine uses a common-cold virus to deliver a coronavirus antigen into cells to stimulate the immune system to fight off an infection.
Other vaccines continue to make significant progress. An Oxford University project is regarded as offering “the best chance of having something protective against the virus as we go into winter”, MPs have been told.
It is being tested in Brazil and South Africa, where the case numbers are high. Astra Zeneca, the company partnering with Oxford, is to start a trial with 30,000 people in the US. European countries are lining up behind the project
What about treatments?
The process of finding new treatments is quicker with lower regulatory hurdles to clear. However, a widely available medication approved for routine use has not materialised yet.
Numerous trials are in progress with prompt endorsement of effectiveness or rejection. There has been too much haste on occasion, as in the case of the anti-malaria drug hydroxychloroquine, which continues to produce mixed results.
Early indications on dexamethasone – a cheap steroid – suggest it reduced deaths by one-third in patients who were on a ventilator. The drug, however, looks to be effective only in patients who are already in a critical state.
Remdesivir reduces the duration of infection in hospitalised patients but not mortality. It does not come cheap, costing $2,340 (¤2,080) per treatment in the US.
Other drugs such as daclatasvir, used to treat Hepatitis C; imatinib to treat leukaemia and favipiravir to treat influenza are showing promise. “Cocktails” of these drugs could be deployed as they are no longer patented, meaning they would be easily and cheaply made available.
What policy lessons can be learned?
For scientists and doctors who have had to wrestle with the rapid spread of Covid-19 across the world, it is a game of constant catch-up.
The bottom line is a safe and effective vaccine remains the best way to achieve herd immunity on a global scale. The lessons for future preparedness are clear.
Immunologist Sir John Bell of Oxford University has criticised the lack of pandemic planning in the UK and particularly the absence of manufacturing capacity for vaccines. Virus outbreaks are, however, a global problem that will have to be addressed through sustained funding over many years.
The world must face the fact that there may never be an effective vaccine