Hopes that the coronavirus pandemic will soon end arose after Pfizer announced that the vaccine it developed is nearly 90% effective.

John Bell, a professor of medicine at Oxford University said the Pfizer / BioNTech team has demonstrated "amazing levels of efficacy," which could mean a return to normalcy by spring.

"I think I'm the first to say this with confidence," Bell told the BBC.

The production of the vaccine has already begun and Pfizer has pledged that it plans to supply the world with 50 million doses in the remaining two months of 2020. In 2021, it plans to produce 1.3 billion doses. Countries will decide for themselves whom they will give priority in vaccination.

In the UK, the joint committee on vaccination and immunization has recommended that since vaccines work reasonably well for older people, the first vaccines will be sent to nursing home workers and residents, and then to everyone over 80 and other health and social care workers. After that, people are expected to receive them in descending order of age.

So far, there is no concern that the vaccine is dangerous, and the two companies have not reported serious side effects. But while Pfizer CEO and Chairman Albert Bourla was very optimistic about the news, other scientists have tried to combine caution with obvious enthusiasm for the first results, warning that complete data are not yet available and that testing is ongoing.

The Phase 3 trial involved more than 43,000 people to see if the vaccine works. Volunteers were given either the COVID vaccine, which was given in two shots about three weeks apart, or a placebo alternative, such as the meningitis vaccine. Neither they nor their doctors know the full result.

There were also concerns that blacks and ethnic minorities are particularly vulnerable to the coronavirus. Approximately 42% of participants from around the world and 30% of test participants from the United States are of various racial and ethnic backgrounds and appear to have been as well protected as everyone else. But, one important question that has no answer is: how long will the vaccine last?

The US and the UK welcomed this experiment and called for patience.

Professor Jonathan Van-Tam said the results showed that the vaccine prevents disease, but "we don't know the consequences yet, so please don't relax."

Nonetheless, many countries have already ordered the vaccine from Pfizer / BioNTech.

The UK has purchased 40 million doses, enough for 20 million people because only two doses are needed per person.

The EU, meanwhile, has purchased 200 million doses that it will distribute.

And, as early as 2020, Pfizer has signed a $ 1.95 billion (£ 1.5 billion) contract with the US government to supply 100 million doses.

However, low-income countries may face some challenges as the vaccine requires an ultracold chain: it must be stored at -70°C to -80°C. BioNTech CEO Ugur Sahin said his company is studying whether the vaccine can survive up to five days at a normal refrigerator temperature of 4°C.

In Germany, the government plans to set up vaccination centers equipped with ultra-low temperature freezers for the first round of vaccinations.