Courtesy The Times

Britain should be heading back to normal by the spring, scientists said yesterday, after the announcement of a vaccine that is 90 per cent effective in stopping the coronavirus.

Jonathan Van-Tam, the deputy chief medical officer for England, said that the huge milestone” meant this wave of infection could be the last that Britain endured.

He said he was hopeful that the first Britons could be injected with the Pfizer and Biontech vaccine before Christmas. Britain has bought 40 million doses in advance, enough to inoculate 20 million people, and the NHS is preparing to start with the most vulnerable.

Scientists also said that the apparent success of the vaccine was a positive sign for others, such as the Oxford project, which is expected to report findings within weeks.

Stock markets rose sharply in response to the announcement, which Albert Bourla, Pfizer’s chief executive, described as a great day for science and humanity”.

The FTSE 100 enjoyed its best day since March, rising by 4.7 per cent, or 276.27 points, to close at 6,186.29, and the Dow Jones industrial average in New York improved by more than 1,500 points to hit a new intraday high.

In other developments:

• Half a million instant Covid-19 tests will be sent to councils within days.

• Four former prime ministers urged Boris Johnson in the summer to throw the full weight of the British state” behind coronavirus testing, it emerged.SPONSOREDA simple change that could get you through anxious times2 women share the story behind their love of teaching

• Donald Trump Jr cast suspicion over the timing of Pfizer’s announcement, suggesting that it was delayed to harm his father’s election prospects. He wrote on Twitter: Nothing nefarious about the timing of this at all right?” He concluded with an eye-rolling emoji.

• Quarantine for travellers to Britain could be scrapped under plans for one-hour Covid-19 tests on arrival, the transport secretary said.

• Ofsted warned that school and nursery closures had led to children regressing in basic learning and social skills.

• Britain recorded another 21,350 coronavirus cases, up 3.9 per cent in a fortnight, while there were 194 deaths over a 24-hour period.

The prime minister said last night that the Pfizer announcement was a sign that the scientific cavalry” was on its way, but he emphasised that it was very, very early days”.

Matt Hancock, the health secretary, told Times Radio that Pfizer’s announcement was a promising step” but there would be more steps to come” before any return to normality.

Warning against any sudden relaxation of restrictions, he added: I want life to be back to as close as normal as soon as possible. We are all pleased to see some light at the end of the tunnel but it’s absolutely crucial in the meantime that we hold our resolve.”

He went on to stress that the roll-out of the vaccine would be a colossal exercise … an NHS-led project supported by the armed forces”.

Scientists have still not seen the full data from the vaccine trials. In particular they said that they wanted to understand its effectiveness in older people, whether it stopped transmission as well as illness, and how much long-term immunity it conferred.

The preliminary results, based on 94 infections in the trial group, greatly exceeded the hopes of most scientists. To be approved, the vaccine had to prevent 50 per cent of symptomatic infections. The results make it more likely that other vaccines, which use the same target on the virus, will also be successful.

Sir John Bell, regius professor of medicine at Oxford University, was hopeful that this marked the beginning of the end of the pandemic. I’m really delighted by this result, for no other reason than it shows you can make a vaccine against this little critter,” he said.

When asked by the BBC if this could mean a return to normality by the spring, Sir John, who is involved in the Oxford vaccine, said: Yes, yes, yes. I’m the first guy to say that, but I will say it with some confidence.”

Professor Van-Tam said that the results were a great success on their own, and also a proof of principle. This is like getting to the end of the playoff final, it’s gone to penalties, the first player goes up and scores the goal,” he said. You haven’t won the cup yet, but it tells you that the goalkeeper can be beaten.”

He said that the public would not see an immediate benefit and, alongside Mr Johnson yesterday, warned that the country must not let up on social distancing. Frankly, we’re in the middle of the second wave and I don’t see the vaccine making any difference for the wave we are now in,” he said. I’m hopeful that it may prevent future waves, but this one we have to battle through to the end. We’ve seen a swallow, but this is very much not the summer.”

The vaccine, which is based on experimental mRNA” technology, will have to be approved by regulators, who will demand the full data. The trial will continue and it will be a fortnight before they have collected enough data to satisfy safety criteria. However, it is expected that the process will then be expedited, assuming that all criteria are met.

Pfizer and its German partner Biontech, founded by Ozlem Tureci and Ugur Sahin, anticipates supplying ten million doses to Britain by the end of the year. One of the challenges for the NHS will be to distribute them. Each person vaccinated requires two doses.

The Pfizer vaccine must be stored at minus 70C until the day it is used, when it can be stored in a normal fridge, and experts have warned that the cold chain” logistics will be challenging.

This temperature is far out of the reach of standard refrigerators. The requirements may make holding vaccinations in GP clinics, care homes and other locations difficult.

The doses of the vaccine will be brought to the UK from a manufacturing facility in Belgium and the military is expected to be called in to help with distribution, although that could be limited.

Pfizer has designed a suitcase-sized container to keep the doses at minus 70C for up to ten days. Each container holds between 1,000 and 5,000 doses that are packed with dry ice. However, there are rules on how the containers can be used. After Pfizer delivers them, they must be repacked with fresh dry ice within 24 hours. After that they can only be opened for a minute at a time and not more than twice a day, according to leaked Pfizer documents.

Some of the vaccine candidates under development, specifically the RNA vaccine candidates, require a very challenging cold chain,” Rongjun Chen, a reader in biomaterials engineering at Imperial College London, said. Any break of the cold chain can considerably reduce vaccine potency.”

Kate Bingham, chairwoman of the government’s vaccines taskforce, said last week that up to ten million doses of the Pfizer vaccine could be available by January but cautioned that providing it would be challenging. [mRNA vaccines] may be relatively straightforward to manufacture initially but the cost of deployment and the complexity of deployment is very high. We have to find better vaccine formats,” she said.

After being transported and held in storage the Pfizer vaccine can last for only about 24 hours at normal” refrigerated temperatures, Dr Chen said.

Meanwhile, the Brazilian clinical trial for a Chinese Covid-19 vaccine has come to a halt after the health regulator Anvisa reported a severe adverse” incident.

The health authority said it took place on October 29 but did not provide any further details.

The Sinovac vaccine is one of several in final-stage testing globally. China has already been using it as part of an emergency programme to immunise thousands of people in China.

Sinovac Biotech defended its vaccine, saying in a statement today that it was confident in its safety and that the adverse incident was unrelated to the vaccine”.