A questão é são baseadas no seguinte texto:
A vaccine which can prevent nine out of 10 people getting Covid-19 is set to be put forward for emergency approval
Its developers, Pfizer and BioNTech, said it had been tested on 43,500 people, with no safety concerns raised
What is the new vaccine and how effective is it?
The vaccine trains the immune system to fight coronavirus. It is a new type of vaccine called an RNA vaccine and uses a tiny fragment of the virus' genetic code. This starts making part of the virus inside the body, which the immune system1 recognises as foreign and starts to attack. It is given in two doses - three weeks apart - and early data suggests it protects more than 90% of people from developing Covid symptoms.
Who will get it first and how soon can I have it?
It depends how old you are, as age is the biggest risk factor2 for severe Covid-19. In the UK, older care home residents3 and care home staff4 are top of the preliminary priority list. They are followed by health workers such as hospital staff and the over 80s. People are then ranked by age, with people under 50 at the bottom of the list. The first jabs may take place before Christmas if everything goes smoothly. The vaccine will be delivered through care homes, GPs and pharmacists as well as "go-to" vaccination centres set up in venues such as sports halls. However, there are logistical challenges5 to overcome - such as the need to keep the vaccine at minus 80C during transportation from the manufacturing lab to vaccination venues. The jab must be thawed before it is given to a patient and can be stored in a normal fridge for a few days before being administered.
Will it offer lasting protection?
It is impossible to know and we will find the answer only by waiting. If immunity does not last then it may be necessary to have a vaccine every year, in the same way as for flu. The data did not show whether protection from Covid-19 was the same in all age groups. However, earlier studies did suggest young and old people could produce an immune response. There will also be some people - such as those with a weak immune system - who will not be able to have the vaccine.
Could the vaccine have long-term health effects
Nothing in medicine is 100% safe - even something we take without thinking, like paracetamol, poses risks. The data so far is reassuring - trials on 43,500 people discovered no safety concerns, although mild side effects have been reported. If there were highly dangerous and common consequences of this vaccination, they should have become apparent. However, rarer side effects may emerge as millions of people are immunised.
Adapted from: https://www.bbc.com/news/explainers-54880084.