A coronavirus vaccine may not provide full immunity and only end up reducing the severity of symptoms, an expert has said.
Speaking to MPs on the science and technology committee, Kate Bingham, the chair of the UK’s vaccine taskforce, said that in the near term, she was “pretty optimistic” about one being developed that reduced symptoms.
She was “relatively optimistic we will find a vaccine that will be able to treat the population”, she said.
“The caveat is... is it a full sterilising vaccine, which means you can’t get infected, or is it one that basically just takes the edge off the symptoms so it reduces mortality?
“Clearly we would like to get to a sterilising vaccine so that people are prevented from being infected.
“But in the near term we may just have to satisfy ourselves with a vaccine that reduces the severity of the disease, and I’m pretty optimistic we will get that.
“How quickly it takes before we get a sterilising vaccine, I don’t have a strong view yet.”
Sir John Bell, regius professor of medicine at the University of Oxford, told the committee the UK should prepare for the “worst” in winter when asked by chairman Greg Clark if the country needed to be ready for a cold season without a vaccine.
Sir John said: “This whole epidemic has relied too heavily on assumptions that have turned out not to be true.
“So my strong advice is be prepared for the worst.”
In the UK, the University of Oxford began trials of its vaccine – ChAdOx1 nCoV-19 – in healthy adult volunteers in April.
Trials are also going ahead in South Africa and Brazil, with hopes that results will be available by September, with the vaccine rolled out after.
It uses a weakened version of a common cold virus that infects chimpanzees which has been genetically changed so it cannot replicate in people.
Imperial College London first gave a small dose of a potential vaccine to a healthy volunteer in 19 June, with a second booster dose to follow. About 300 healthy people are due to participate in the trial.
This vaccine uses synthetic strands of genetic code based on the coronavirus’s genetic material.
It is used to trigger an immune response which could offer protection against COVID-19, and if it is shown to be safe and effective a further trial of 6,000 participants is scheduled for October.
In the US, human vaccine trials by Moderna started in March, and in May it was said there were early indications it could train the immune system to work against coronavirus.
mRNA-1273 uses a small sample of the virus’s genetic code and injects it into patients. Eight people in safety trials gained neutralising antibodies, it was reported.
Sanofi and GSK are working together on a vaccine they hope will be available mid-2021, while potential vaccines are being researched across the rest of the world, including in China and Australia.
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