Tag Archives: AstraZeneca
Blood clots are an extremely rare but serious side effect of AstraZeneca‘s COVID-19 vaccine, regulators announced on Wednesday. The benefits of AstraZeneca‘s vaccine still outweigh the risks, the European Medicines Agency (EMA) said in a press release. Still, the agency’s safety committee said it’s important to know the signs of a possible clot.
A blood clot occurs when the blood thickens and forms a semi-solid mass. It can be a helpful response to stop bleeding in the case of injury, but these blockages can cause problems if they cut off blood flow to a vital area. Blood clots can cause blockages in the legs, abdomen, and lungs. Most of the blood clots associated with the AstraZeneca vaccine have occurred in veins in people’s brains. These clots, known as cerebral venous sinus thrombosis (CVST), can lead to stroke, seizures, and death.
So far, most of the clots reported have occurred in women under 60 years of age within two weeks of vaccination. Since young people are more likely to experience this side effect, UK vaccine regulators recommend that people under 30 do not get the AstraZeneca shot unless they’ve already received their first dose. The EMA said patients who got the AstraZeneca vaccine should seek medical assistance immediately if they have the following symptoms:
- shortness of breath
- chest pain
- swelling in your leg
- persistent abdominal (belly) pain
- neurological symptoms, including severe and persistent headaches or blurred vision
Some mild side effects, like pain at the injection site or other body aches, are common in the days post-vaccine.But if you experience severe or persistent symptoms around four to 20 days after vaccination, you should seek medical attention, according to the World Health Organization. Blood clots are typically treated with anti-clotting medication. Complications can be avoided if the clot is caught early.
COVID-19 Vaccine AstraZeneca confirms 100% protection against severe disease, hospitalisation and death
The primary analysis of the Phase III clinical trials from the UK, Brazil and South Africa, published as a preprint in The Lancet confirmed COVID-19 Vaccine AstraZeneca is safe and effective at preventing COVID-19, with no severe cases and no hospitalisations, more than 22 days after the first dose.
Results demonstrated vaccine efficacy of 76% (CI: 59% to 86%) after a first dose, with protection maintained to the second dose. With an inter-dose interval of 12 weeks or more, vaccine efficacy increased to 82% (CI: 63%, 92%).
The analysis also showed the potential for the vaccine to reduce asymptomatic transmission of the virus, based on weekly swabs obtained from volunteers in the UK trial. The data showed that PCR positive readings were reduced by 67% (CI: 49%, 78%) after a single dose, and 50% (CI: 38% to 59%) after the two dose regimen, supporting a substantial impact on transmission of the virus.
The primary analysis for efficacy was based on 17,177 participants accruing 332 symptomatic cases from the Phase III UK (COV002), Brazil (COV003) and South Africa (COV005) trials led by Oxford University and AstraZeneca, a further 201 cases than previously reported.
“This primary analysis reconfirms that our vaccine prevents severe disease and keeps people out of hospital. In addition, extending the dosing interval not only boosts the vaccine’s efficacy, but also enables more people to be vaccinated upfront. Together with the new findings on reduced transmission, we believe this vaccine will have a real impact on the pandemic,”said Sir Mene Pangalos, Executive Vice President BioPharmaceuticals R&D.
“These new data provide an important verification of the interim data that has helped regulators such as the MHRA in the UK and elsewhere around the world to grant the vaccine emergency use authorisation. It also helps to support the policy recommendation made by the Joint Committee on Vaccination and Immunisation for a 12-week prime-boost interval, as they look for the optimal approach to roll out, and reassures us that people are protected 22 days after a single dose of the vaccine,” explained Professor Andrew Pollard, Chief Investigator of the Oxford Vaccine Trial, and co-author of the paper.
Data will continue to be analysed and shared with regulators around the world to support their ongoing rolling reviews for emergency supply or conditional approval during the health crisis. AstraZeneca is also seeking Emergency Use Listing from the World Health Organization for an accelerated pathway to vaccine availability in low-income countries.
The vaccine can be stored, transported and handled at normal refrigerated conditions (two-eight degrees Celsius/36-46 degrees Fahrenheit) for at least six months and administered within existing healthcare settings.
Scientists in the UK have just recruited the first participants in the world to be part of a new long-acting antibody study. If the treatment is effective, it could give those who have already been exposed to SARS-CoV-2 protection from developing COVID-19.
“We know that this antibody combination can neutralise the virus,” explains University College London Hospitals (UCLH) virologist Catherine Houlihan. “So we hope to find that giving this treatment via injection can lead to immediate protection against the development of COVID-19 in people who have been exposed – when it would be too late to offer a vaccine.”
This might not be the first antibody treatment for COVID-19 you’ve heard of. Outgoing US President Donald Trump was given monoclonal antibodies when he came down with the disease, and in the US two different antibody treatments – casirivimab and imdevimab – received emergency approval back in November. But those antibody treatments are given to patients with mild or moderate COVID-19, who risk progressing to a severe version of the disease.
“In a clinical trial of patients with COVID-19, casirivimab and imdevimab, administered together, were shown to reduce COVID-19-related hospitalisation or emergency room visits in patients at high risk for disease progression within 28 days after treatment when compared to placebo,” the FDA explained in a press statement when the drugs were approved. This new antibody therapy, called AZD7442 and developed by UCLH and AstraZeneca, is a little different. AZD7442 is a combination of two monoclonal antibodies AZD8895 and AZD1061, which both target the receptor binding domain of the SARS-CoV-2 spike protein.
“By targeting this region of the virus’s spike protein, antibodies can block the virus’s attachment to human cells, and, therefore, is expected to block infection,” the team wrote on the US ClinicalTrials.gov website. “Amino acid substitutions have been introduced into the antibodies to both extend their half-lives, which should prolong their potential prophylactic benefit, and decrease Fc effector functionin order to decrease the potential risk of antibody-dependent enhancement of disease.”
Antibodies are little Y-shaped proteins that lock on to a particular section – called an antigen – of a virus, bacterium or other pathogen, and either ‘tag‘ it to be attacked by the immune system, or directly block the pathogen from invading our cells. Normal antibodies are produced by your body after an infection, while monoclonal antibodies are cloned in a lab and can be injected into a person already infected, to give the immune system a hand in the fight.
The researchers are hoping that AZD7442 – which is just starting the Storm Chaser study (the name for its phase 3 trial) – provides protection for those that have been exposed to the virus but do not yet have symptoms. Effectively, they’re trying to stop COVID-19 happening in the first place. “If you are dealing with outbreaks in settings such as care homes, or if you have got patients who are particularly at risk of getting severe COVID, such as the elderly, then this could well save a lot of lives,” said University of East Anglia infectious disease expert Paul Hunter.
Britain could have 19million doses of Oxford and AstraZeneca‘s coronavirus vaccine by the end of the year after clinical trials showed it is up to 90 per cent effective at preventing infection and can be stored cheaply in a fridge. President of AstraZeneca, Tom Keith-Roach said today that, on top of the four million doses on standby for the UK, a further 15million could be ready to roll out by the end of next month. They will be given to healthcare workers and the elderly first, subject to approval by regulators.
The vaccine is expected to cost just £2 per dose and can be stored in ordinary equipment, unlike other jabs made by Pfizer and Moderna that showed similarly promising results last week but need to be kept in ultra-cold temperatures using expensive equipment. It’s also a fraction of the price, with Pfizer‘s costing around £15 per dose and Moderna‘s priced at about £26 a shot.
Oxford‘s trials found the jab has a nine in ten chance of working when administered as a half dose first and then a full dose a month later. Efficacy drops to 62 per cent when someone is given two full doses a month apart.
Immunogenicity responses similar between older and younger adults
One of the world’s leading COVID-19 experimental vaccines produces a immune response in both old and young adults, raising hopes of a path out of the gloom and economic destruction wrought by the novel coronavirus. The vaccine, developed by the University of Oxford, also triggers lower adverse responses among the elderly, British drug maker AstraZeneca Plc AZN.L, which is helping manufacture the vaccine, said on Monday. A vaccine that works is seen as a game-changer in the battle against the novel coronavirus, which has killed more than 1.15 million people, shuttered swathes of the global economy and turned normal life upside down for billions of people.
“It is encouraging to see immunogenicity responses were similar between older and younger adults and that reactogenicity was lower in older adults, where the COVID-19 disease severity is higher,” an AstraZeneca spokesman said.
Moderna should have enough data from its late-stage trial to know whether its coronavirus vaccine works in November, CEO Stephane Bancel said Thursday. The company could have enough data by October, but that’s unlikely, Bancel said during an interview on CNBC’s “Squawk Box.”
“If the infection rate in the country were to slow down in the next weeks, it could potentially be pushed out in a worst-case scenario in December,” he added.
Moderna‘s experimental vaccine contains genetic material called messenger RNA, or mRNA, which scientists hope provokes the immune system to fight the virus. In July, the company released early-stage data that showed its potential vaccine generated a promising immune response in a small group of patients.
Bancel’s comment came four days after the CEO of Pfizer said its vaccine could be distributed to Americans before the end of the year. CEO Albert Bourla told CBS’ “Face the Nation” that the company should have key data from its late-stage trial for the Food and Drug Administration by the end of October. If the FDA approves the vaccine, the company is prepared to distribute “hundreds of thousands of doses,” he said.
There are around 40 different coronavirus vaccines in clinical trials – including one being developed by the University of Oxford that is already in an advanced stage of testing. The virus spreads easily, and the majority of the world’s population is still vulnerable to it. A vaccine would provide some protection by training people’s immune systems to fight the virus so they should not become sick. This would allow lockdowns to be lifted more safely, and social distancing to be relaxed.
Research is happening at breakneck speed. About 240 vaccines are in early development, with 40 in clinical trials and nine already in the final stage of testing on thousands of people. Trials of the Oxford vaccine show it can trigger an immune response, and a deal has been signed with AstraZeneca to supply 100 million doses in the UK alone. The first human trial data back in May indicated the first eight patients taking part in a US study all produced antibodies that could neutralise the virus. A group in China showed a vaccine was safe and led to protective antibodies being made. It is being made available to the Chinese military.
Other completely new approaches to vaccine development are in human trials. However, no-one knows how effective any of these vaccines will be. A vaccine would normally take years, if not decades, to develop. Researchers hope to achieve the same amount of work in only a few months. Most experts think a vaccine is likely to become widely available by mid-2021, about 12-18 months after the new virus, known officially as Sars-CoV-2, first emerged. That would be a huge scientific feat, and there are no guarantees it will work. But scientists are optimistic that, if trials are successful, then a small number of people – such as healthcare workers – may be vaccinated before the end of this year. It is worth noting that four coronaviruses already circulate in human beings. They cause common cold symptoms and we don’t have vaccines for any of them.
The governor of Brazil’s São Paulo State said on Wednesday that Phase 3 clinical trials of a potential COVID-19 vaccine developed by China’s Sinovac Biotech Ltd have shown promising results and it may be available to Brazilians as early as December.
Governor João Dória added that Phase 2 trials of the potential vaccine had shown an immune response of 98% in the elderly. Some 9,000 Brazilians are participating in the Sinovac vaccine trials, which are being conducted by the Butantan Institute in Sao Paulo city, the State capital. Brazil, which has the third worst outbreak of the novel coronavirus in the world after the United States and India, has become a testing ground for at least two vaccine candidates.
One such vaccine is being developed by AstraZeneca, which has had to pause global trials after an unexplained illness in a participant in Britain. At the start of next year, Phase 3 trials of Russia’s “Sputnik-V” COVID-19 vaccine will also be conducted on 10,000 volunteers in Brazil in partnership with the State of Paraná’s Technology Institute, known as Tecpar.