Hopes of getting a Covid-19 vaccine were boosted again today after an experimental Chinese jab was found to be safe and produce an immune response.
Every volunteer given a double-dose of state-owned firm Sinopharm’s vaccine made antibodies against SARS-CoV-2, the coronavirus that causes Covid-19.
In theory, this would protect them from catching the virus again in the future, or at least protect them from developing a severe bout of the disease. But this has not been proven by the scientists yet — they only injected fewer than 1,000 participants.
Ministers repeatedly insisted Britain could start to use a Covid-19 jab by September — but the Government has still yet to approve any vaccine because of a lack of data that they work.
Number 10’s own vaccine tsar yesterday admitted the odds of getting one rolled-out before Christmas were ‘slim’, with World Health Organization officials now claiming one won’t be ready until 2021 at the earliest for the most vulnerable.
Oxford University’s experimental jab is considered the front-runner but Downing St has also bought supplies of 340million different vaccines, in a spread-betting approach to ensure the UK doesn’t miss out on any scientific breakthrough.
The results of the first two phases of clinical trials of Sinopharm’s vaccine, published in The Lancet, come after experts released promising results of another candidate jab made by Pfizer and its German partner.
A vaccine is considered key to ending the Covid-19 pandemic because it ensures a person will not catch the coronavirus.
All hopes are being pinned on finding one proven to work, but until then, measures such as social distancing have to be used to prevent the virus spreading.
More than 600 healthy adults were given Sinopharm’s jab, dubbed BBIBP, and none suffered an adverse reaction.
The most common side effect, reported by a quarter of volunteers, was pain at the point the needle was injected — which is common for any jab.
Two doses were shown to be more powerful than one, which is typical for the way BBIBP is made.
It is an inactivated vaccine, meaning it contains the virus but it has been grown in a laboratory and then killed, so it is not infectious.
Inactivated vaccines are well known and have been used against diseases such as influenza, measles and rabies. But they usually don’t provide immunity that’s as strong as live vaccines, so several doses over time may be necessary.
Adults over the age of 60 took a longer time to mount immunity, according to the results of the study, carried out by Beijing Institute of Biological Products.
But all volunteers had antibodies — proteins of the immune system which fight infection — seven weeks after injection compared with four in those under 60 years old.
This is not unusual because the immune system slows with ageing, meaning it takes longer for older people to respond to a vaccine or illness. It is also seen for influenza vaccines.
Antibodies are produced by B-cells in the immune system. They can take several days to build up.
They are stored by the immune system so that if the virus enters the body again, they can react faster to clear it from the body before it makes a person sick.