Latest breakthrough comes as PM says he hopes most at-risk could be immunised by Easter
The world is moving a “step closer” to ending the coronavirus pandemic, the scientist behind Britain’s first vaccine has declared as Boris Johnson said he hoped the majority of those most at-risk could be immunised by Easter.
Quick guide Who in the UK will get the new Covid-19 vaccine first? Show Hide The UK government’s joint committee on vaccination and immunisation has published a list of groups of people who will be prioritised to receive a vaccine for Covid-19. The list is: 1 All those 80 years of age and over and health and social care workers. 2 All those 75 and over. 3 All those 70 and over. 4 All those 65 and over. 5 Adults under 65 at high at risk of serious disease and mortality from Covid-19. 6 Adults under 65 at moderate risk of at risk of serious disease and mortality from Covid-19. 7 All those 60 and over. 8 All those 55 and over. 9 All those 50 and over. 10 Rest of the population.
Successful trial results for the Oxford University/AstraZeneca vaccine, suggesting it could protect up to 90% of people, mark the third set of promising findings in as many weeks. Before this year, there had never been a vaccine for a coronavirus.
The development came as a relief to the UK government, which has invested heavily and ordered 100m doses – enough for the whole adult population
Matt Hancock, the health secretary, said that subject to regulatory approval, the bulk of the UK rollout could come in the new year while the prime minister said a “favourable wind” could see the majority of people most in need of a vaccination receiving one by Easter. “I don’t want to give any more hostages to fortune than that, but that’s the best information we have,” he told a Downing Street press conference.
It was also hailed as exciting news for the rest of the world, especially low-income countries. The vaccine is low-cost, at £3 a dose compared to over £20 for the Pfizer/BioNTech and Moderna vaccines, which also released results this month.
The latest vaccine does not need to be shipped and stored in ultra-cold freezers, solving a huge logistical problem posed by the others, and there is good data that it will work as well in the elderly as in younger people.
“The announcement today takes us another step closer to the time when we can use vaccines to bring an end to the devastation caused by [Covid-19],” Prof Sarah Gilbert from the University of Oxford, who has led the research, told the Guardian.
“We will continue to work to provide the detailed information to regulators. It has been a privilege to be part of this multinational effort, which will reap benefits for the whole world.”
The long-anticipated efficacy results revealed on Monday delivered a major surprise. Overall efficacy from trials in the UK and Brazil was 70%, but the vaccine worked better in people given a lower first dose. Those who got a half dose, followed four weeks later by a full dose, enjoyed 90% protection, while efficacy among those who had two full doses was 62%.
While AstraZeneca said it would submit its data to the UK regulator immediately, new trials will have to be run in the United States, where the half-dose regime was not being tested, pushing back any possibility of the vaccine being available there before Christmas.
The scientists said they could not fully explain why a lower first dose appeared to give better protection. “We think that by giving a smaller first dose that we’re priming the immune system differently – we’re setting it up better to respond,” said Prof Andrew Pollard, director of the Oxford Vaccine Group and chief investigator of the trial. “And what we don’t know at this moment is whether that difference is in the quality, or the quantity of immune response.”
Gilbert said people should not assume the other two vaccines, which achieved 95% efficacy in trials and were both made using a different, novel mRNA technology that uses genetic code instead of virus, were better. The trials had not been set up to measure the same things.
“We need to bear in mind these are early data,” she said. “We have additional trials running. Those numbers may be a little bit different in the ultimate analysis. You can’t directly compare the readout from different clinical trials. If you don’t have the same criteria for enrolling people or endpoint cases, you can’t compare.”
Global experts were enthusiastic about the vaccine, which has long been one of the biggest hopes for taming the pandemic worldwide. Oxford/AstraZeneca have joined Covax, the World Health Organization-led programme to distribute vaccines to all countries and done deals with manufacturers in other countries. The Serum Institute of India is to make 1bn doses.
“If there is anyone out there who still doubts that a Covid-19 vaccine can help us out of this pandemic, the announcement today from Oxford University/AstraZeneca should surely dispel that doubt,” said Eleanor Riley, professor of immunology and infectious disease at the University of Edinburgh.
“This is excellent news – another vaccine that can prevent symptomatic infections and, even better is cheap to produce and easy to distribute.”
Dr Richard Hatchett, chief executive of the Coalition for Vaccine Preparedness (CEPI) which is involved in Covax, said they believed the Oxford vaccine “has the potential to significantly alter the course of the global pandemic. The data released today suggest the vaccine is safe and comparable in its efficacy to other licensed vaccines – including influenza – that are widely used to protect people around the world today.”
Oxford/AstraZeneca say they believe their vaccine may help stop transmission, potentially preventing the spread of the coronavirus as well as protecting people from becoming ill. Unlike other vaccines, they have collected weekly swabs sent from UK volunteers given home test kits. The data, which has not yet been published, suggests a reduction in asymptomatic infection among people who were vaccinated.
Hancock said if the data was approved by the regulator, the vaccine would be available for most people next year. “This is really encouraging news on the Oxford/AstraZeneca vaccine, that obviously we’ve been backing since the start,” he told Sky News. “And I’m really very pleased, really welcome these figures, this data, that show that the vaccine in the right dosage can be up to 90% effective.
“Of course, it’s vital that the independent regulator, the MHRA [Medicines and Healthcare products Regulatory Agency], will need to look at the data, will need to check to make sure that it’s effective and safe of course. But we’ve got 100m doses on order and should all that go well, the bulk of the rollout will be in the new year.”
Dr Charlie Weller, head of vaccines at Wellcome, said every effective vaccine would be needed. “To have interim results from three vaccine teams within a year is incredible, and testament to a truly extraordinary global scientific effort. We need a range of vaccines, that can protect people of different ages and backgrounds wherever they live, and to be able to manufacture enough doses for the world.
“To meet the aim of vaccinating high-risk populations around the world over the next year we need at least 2bn vaccine doses.”
Não bastasse a polêmica em torno da , cujo relatório da fase III atrasou dois meses devido à baixa eficácia geral da vacina, fato que o diretor do Insituto Butantan, Dimas Covas, e o Governo de São Paulo tentaram evitar divulgar, a vacina , desenvolvida pela Universidade de Oxford com a AstraZeneca - e no Brasil com ajuda da  - também apresenta problemas na eficácia, já que até agora o número global geral não foi divulgado.  

No Reino Unido, onde ela recebeu liberação para uso emergencial, a eficácia foi considerada como sendo de 62%, enquanto no Brasil a imprensa reporta 70% - sendo que a eficácia comprovada para o caso de meia dose antes e uma dose inteira depois é de 90%, dado descoberto por acaso devido a um erro na aplicação, já que estavam previstas duas doses inteiras. “Devido ao erro, foi possível notar uma diferença de eficácia, sendo de 62% entre o grupo de voluntários que recebeu duas doses completas e de 90% entre aqueles que receberam meia dose seguida de uma dose completa. Novamente, mais tarde, o laboratório reconheceu que a taxa de 90% não inclui os idosos acima de 55 anos, pois não haviam sido feitos testes suficientes nesse público”, reportou o UOL Notícias. 

Tanto a ChAdOx1 como a CoronaVac já estão sendo analisadas pela Anvisa e devem ser liberadas para uso emergencial nos próximos dias. 

'''O que se sabe de positivo?'''

Os dados preliminares após a fase III revelaram que em adultos de 18 a 55 anos, aplicada em meia dose antes e uma dose inteira depois, ela tem 90% de eficácia. 

No entanto, os grupos a serem priorizados com a imunização estão, justo, fora deste perfil: a prioridade são os idosos, junto com os profissionais da linha de frente no combate à covid-19 e pessoas com comorbidades.