A coronavirus vaccine being developed by GlaxoSmithKline and its French partner, Sanofi, will be delayed until the end of next year after trials revealed it failed to produce a strong immune response in older people.
The drug companies hoped to have regulatory approval for the candidate vaccine in the first half of 2021, but interim results from a phase 1/2 trial showed an “insufficient” response in the over-50s, the age group most vulnerable to severe Covid-19.
The results released on Friday are a stark reminder that despite a flurry of positive results from vaccines produced by Pfizer/BioNTech, NIH/Moderna and Oxford University/AstraZeneca, developing effective vaccines at speed is no simple task.
In those aged 18- to 49-years-old, the GSK/Sanofi vaccine produced an immune response similar to that seen in patients who recovered from Covid-19, but in older adults companies reported a “low immune response … likely due to an insufficient concentration of the antigen”. The antigen is the viral protein that primes the immune system to fight coronavirus.
The companies will now reformulate the vaccine and launch a phase 2 trial in February with an aim to deliver approved shots in the last quarter of 2021, barring any further setbacks.
Britain has pre-ordered 60m doses of the GSK/Sanofi vaccine as part of its portfolio of 355m shots from seven different vaccine developers. This week, the UK administered the first of 40m shots of the Pfizer/BioNTech vaccine. The Oxford/AstraZeneca vaccine is expected to join the mass vaccination programme but is awaiting approval from the UK regulator.
When and how will I be able to get a Covid vaccine in the UK?
Now that the UK has authorised the first Covid vaccine, who will get it first?
The government’s Joint Committee on Vaccination and Immunisation (JCVI) says its priority is to prevent Covid-related deaths and protect health and social care staff and systems.
Elderly care home residents and their carers are first on the JCVI’s list because their risk of exposure to the virus is higher and because the risk of death closely correlates with older age. They are followed in priority by anyone else over 80 and frontline health and social care workers.
Even so, for pragmatic reasons NHS staff are likely to be the first group to receive the Pfizer/BioNTech jab. This is because the vaccine needs to be stored at ultra-cold temperatures, which can be achieved more easily by using hospital facilities
Are there enough doses to reach all the priority groups?
Together, care home residents, their carers and the over-80s make up nearly 6 million people, and frontline NHS staff a further 736,685. Matt Hancock, the health secretary, has said he expects 10m doses of the Pfizer/BioNTech vaccine to be available this year, so if this is the only vaccine authorised, everyone else would have to wait until further doses become available next year.
Where will I go for the vaccine?
Covid-19 vaccines are expected to be delivered at three types of venue: NHS trust “vaccine hubs” at hospital sites; mass vaccination centres, which are in the process of being set up at places such as football stadiums, conference buildings and racecourses – these are expected to vaccinate up to 5,000 people a day; and at GP surgeries and pharmacies. GPs can also visit care home residents and housebound patients at home without them needing to travel.
How far apart will the two doses be administered, and will I protected after the first?
While there is some evidence to indicate high levels of short-term protection from a single dose of vaccine, a two-dose schedule is what has been approved by the MHRA.
The second dose will need to be delivered at least 21 days after the first, and both will be injected into the deltoid muscle – the thick triangular muscle we use to raise each arm.
For the Pfizer vaccine, its efficacy rate was calculated seven days after the second shot. It is likely that people will have some protection before this, but this is how long it will take for full protection to kick in. We will learn more about the extent of protection and how long it lasts as data from ongoing clinical trials comes in.
Can I pay to get the vaccine privately?
Unlikely. England’s deputy chief medical officer, Jonathan Van-Tam, has said he believes Covid-19 vaccines should be delivered according to clinical priority rather than allowing people to jump the queue if they can afford it.
Will I be able to choose which vaccine I have?
Also unlikely, at least in the short to medium term. Assuming more than one vaccine is approved, the priority will be distributing any available doses to the people who need it as quickly as possible.
Roger Connor, the president of GSK Vaccines, said the results of the study were “not as we hoped”, adding: “It is also clear that multiple vaccines will be needed to contain the pandemic.
“Our aim now is to work closely with our partner Sanofi to develop this vaccine, with an improved antigen formulation, for it to make a meaningful contribution to preventing Covid-19.”
Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said the results highlighted why many scientists were amazed at the success of the BioNTech, Moderna and Oxford vaccines.
“The first few vaccines to get to an interim analysis in phase 3 trials were unusual to have got that far without notable problems,” he said. “This shows what we know – that it is not always easy to develop a new vaccine to the point of being used to prevent the disease. Getting a vaccine that shows efficacy in the relevant age and other groups is not a straightforward path; many uncertainties can persist.”
Evans said it was possible that adjustment of doses and constituents of the vaccine could improve responses in elderly people, but that it was not guaranteed.
“It shows that we need to continue development of vaccines for Covid-19, because not every vaccine will get to the point of finishing phase 3 trials with demonstrated efficacy and lack of serious harm, and even those that do get there may find problems after their introduction that restrict or even prevent their widespread usage.
“We are certainly not at the end of the process for vaccines against Covid-19 and there will be things that surprise us as we progress. While any delay is disappointing, it shows that vaccines are not as simple to produce as the early successes might have implied,” he said.