Oxford-Astra COVID vaccine shows dual immune action: researcher


A coronavirus vaccine that the University of Oxford is developing with AstraZeneca Plc has shown promising results in the first human tests, a sign of progress in the pursuit of high-stakes fire to defeat the pathogen.The vaccine has increased the levels of protective neutralizing antibodies and immune T cells that target the virus, according to study organizers. The results were published Monday in the medical journal The Lancet.

AstraZeneca shares rose 10% in London, but gave up some of those gains to trade 2.8% more, with researchers warning that the results were preliminary. A positive result was widely expected after reports last week lifted the stock, as the vaccine has already been tested in more advanced ways.

“We are seeing very good immune responses, not only on neutralizing antibodies, but also on T cells,” Adrian Hill, director of the Jenner Institute at Oxford, said in an interview. “We stimulate both arms of the immune system.”

Other vaccine projects, including injections under development by Chinese CanSino Biologics Inc., and a partnership between Pfizer Inc. and BioNTech SE also provided positive updates on the trials on Monday. The findings reinforce optimism about how to tackle a pandemic that has killed more than 600,000 people and sparked economic turmoil since it erupted earlier this year. Moderna Inc., another leader, last week released the results of an early test that showed its vaccine increased levels of antibodies that fight the virus.


Although stimulating the production of neutralizing antibodies does not prove that a vaccine will be effective, it is considered an important first step in testing. The results of animal tests had already shown that the Oxford-AstraZeneca vaccine elicited an immune response.

The phase 1 trial, which took place between April 23 and May 21, involved 1,077 healthy adults between the ages of 18 and 55 with no history of Covid-19. A control group received a placebo meningitis vaccine and 10 participants received two doses of the vaccine one month apart. The vaccine caused minor side effects, which could be reduced by taking paracetamol. There were no serious jab adverse events.

Most of the study participants received a single dose of the vaccine. Astra will prioritize a two-dose regimen in future testing, Hill said.

“It gives higher antibody titers, which is important in the future,” he said. Moderna will also test a two-dose regimen.

A single dose of Oxford vaccine resulted in a four-fold increase in antibodies to the virus’s advanced protein in 95% of participants one month after the injection, AstraZeneca said in a statement. SARS-CoV-2 uses the spike protein to enter cells. A T cell response was induced in all participants who received the vaccine, peaking on day 14 after injection.

“It’s good, not unexpected, but good to have confirmed it. The vaccine worked and developed the most important neutralizing antibodies, in most cases after one injection and in all cases after 2 injections, “said Ian Jones, professor of biomedical sciences at the University of Reading.

Around the world, around 160 coronavirus vaccines are in different stages of development, according to the World Health Organization. Oxford shooting is close to the front of the field and has already started the final stage testing. AstraZeneca has said it could start delivering doses to the UK as early as September.

“We want other companies to have vaccines that work too because the world will get more vaccines sooner,” said Hill. “We just think there is an advantage in stimulating both arms of the immune system well.”

AstraZeneca received a boost when the United States pledged up to US $ 1.2 billion for development. Under its deal with the British drugmaker, the United States could start receiving supplies as early as October.

The UK also struck a supply deal for the vaccine, but on Monday gained access to experimental vaccines from other drugmakers to cover its bets and collect enough doses to cover its population of 66 million. ‘inhabitants. The government has entered into agreements with Pfizer, BioNTech and Valneva SE.

Combat COVID

Businesses and universities are using a range of approaches in the fight against Covid-19. The Oxford team have developed technology that can speed up the process by using a harmless virus to transport some of the pathogen’s genetic material into cells to generate an immune response. The proposed vaccine is made from a weakened version of a common cold virus that has been genetically engineered to prevent it from growing in humans.

Oxford inserted genetic material from the SARS-CoV-2 virus surface protein spike to trigger the immune system to fight back. The platform stimulates both antibodies and high levels of killer T cells, a type of white blood cell that helps the immune system destroy infection.

“We’re very encouraged,” Hill said. While the test doesn’t prove the vaccine will work, “I think we’re a little more confident that it should work this week than last week.”


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