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The Oxford/AstraZeneca COVID-19 Vaccine: Encouraging Interim Results
Given that severe, potentially fatal COVID-19 is more common in older adults, candidate vaccines must prove useful in that population. The first study indicates that the Oxford/AstraZeneca vaccine has similar immunogenicity across all age groups after a boost dose, with lower reactogenicity in older adults. These data are encouraging, although the participants were mostly healthy. Outcomes may differ in those with comorbidities or frailty; thus, real-world protection across age groups remains to be determined. The interim analysis suggests that the efficacy of two SDs of this vaccine is lower than that reported with either of the two mRNA vaccines. The finding of higher efficacy among those who received first an LD then an SD should be further explored; if confirmed, this regimen would not only provide efficacy comparable to that of the mRNA vaccines but also would translate to more doses available for distribution globally.
The ChAdOx1 nCoV-19 vaccine (also known as AZD1222), developed by Oxford University and AstraZeneca, is a chimpanzee adenovirus-vectored vaccine that targets the SARS-CoV-2 spike glycoprotein. Two reports detail the vaccine's safety and immunogenicity in various populations (including older adults) and provide an interim efficacy analysis of four pooled studies.
In a blinded phase 2 study, researchers examined the safety and immunogenicity of a low dose (LD; 2.2x1010 virus particles) or standard dose (SD; 3.5–6.5x1010 virus particles) of vaccine administered as either one or two doses (prime + boost 28 days later), with the meningococcal MenACWY vaccine as a control. A total of 560 participants were enrolled (160 aged 18–55, 160 aged 56–69, and 240 aged ≥70; 50% female, 95% white, and 98% nonsmokers).
Local and systemic reactions were more common in those receiving ChAdOx1 nCoV-19 than those receiving control. Injection site pain and tenderness (the most common local adverse reactions) were reported after two SDs in 88% of participants aged 18–55, 73% of those aged 55–69, and 61% of those 70 or older. Fatigue, headache, fever, and myalgias (the most common systemic adverse reactions) were reported by 86%, 77%, and 65% of participants in the three age cohorts. Anti-spike IgG responses at day 28 were similar after prime vaccination with SD or LD, but decreased with advancing age. After boost vaccination, median anti-spike IgG responses were similar across the three age cohorts regardless of dose. By 14 days after the boost, >99% of participants had neutralizing antibody responses. T-cell responses peaked at day 14 after prime vaccination, were similar in all groups regardless of age and dose, and did not increase significantly after boost vaccination.
In an interim efficacy analysis pooling the results of four randomized, controlled trials in the U.K., Brazil, and South Africa that included 11,636 participants who had been assigned to either two SDs or an LD followed by an SD of vaccine, 131 cases of symptomatic COVID-19 occurred >14 days after the second dose (30 of 5807 participants in the vaccine arm and 101 of 5829 participants in the control arm) yielding an efficacy of 70.4% (95% confidence interval, 54.8–80.6). In participants who received two SDs, vaccine efficacy was 62.1%. In the subset receiving an LD followed by an SD, efficacy was 90.0%. Ten participants, all in the control arm, were hospitalized with COVID-19, two of whom had severe disease (including one who died). With 74,341 months of safety follow-up, three adverse events were classified as possibly related to vaccine of which only one was in the COVID-19 vaccine group.
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"The AZD1222 vaccine against COVID-19 has an efficacy of 63.09% against symptomatic SARS-CoV-2 infection."
Does it prevent infection and transmission?
No substantive data are available related to impact of AZD1222 on transmission or viral shedding.
In the meantime, we must maintain and strengthen public health measures that work: masking, physical distancing, handwashing, respiratory and cough hygiene, avoiding crowds, and ensuring good ventilation.
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South Africa halts AstraZeneca jab over new strain
South Africa has put its roll-out of the Oxford-AstraZeneca vaccine on hold after a study showed "disappointing" results against its new Covid variant.
Scientists say the strain accounts for 90% of new Covid cases in South Africa.
The study, involving around 2,000 people, found the vaccine offered "minimal protection" against mild and moderate cases of Covid-19.
South Africa has received 1m doses of the AstraZeneca jab and was due to start vaccinating people next week.
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Quebec confirms 1st death related to AstraZeneca-linked blood clots
Woman identified as 54-year-old Francine Boyer
Quebec has confirmed the death of a woman after the AstraZeneca-Oxford COVID-19 vaccine she received in early April led to a rare blood clot in her brain.
The province's Ministry of Health said the woman's death was caused by a vaccine-induced immune thrombotic thrombocytopenia (VITT).
She has been identified by her family as 54-year-old Francine Boyer.
According to a news release sent out Tuesday evening, Boyer and her husband Alain Serres both took the AstraZeneca vaccine on April 9.
While he experienced no complications, she was hospitalized and later died on April 23.
The release states that in the days following her vaccination, Boyer suffered from severe fatigue and headaches. She was hospitalized locally and then transferred to the Montreal Neurological Institute as her condition worsened.
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Ontario man speaks out after father has severe stroke from rare blood clot following AstraZeneca vaccine
5 cases of blood clots have been reported in Canada out of more than 1.1 million doses given
Kyle says his father developed strange symptoms almost two weeks after receiving the vaccine — including confusion, headaches and numbness on his left side.
His mother called 911 and took him to a southern Ontario hospital, where Kyle says health-care workers attributed his condition to his previous cancer diagnosis and he was sent home.
But his father then collapsed in the middle of the night and was rushed to another hospital where he was later diagnosed with a stroke caused by vaccine-induced immune thrombotic thrombocytopenia (VITT) on Monday after receiving the AstraZeneca shot.
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Alberta woman in her 50s dies of rare blood clot linked to AstraZeneca vaccine
Vaccine-induced immune thrombotic thrombocytopenia occurs in 1 in every 100,000 shots
An Alberta woman in her 50s has died from a rare blood clot condition after receiving the AstraZeneca-Oxford vaccine, says the province's chief medical officer of health.
In a statement Tuesday, Dr. Deena Hinshaw said the woman died of vaccine-induced immune thrombotic thrombocytopenia (VITT). It's Alberta's first death linked to the vaccine.
Hinshaw said the woman was only the second confirmed case of VIIT in the province. More than 253,000 doses of AstraZeneca or CoviSHIELD that have been administered in Alberta.
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Researchers in Germany and Norway have reportedly found a mechanism that could cause the AstraZeneca-Oxford vaccine to create blood clots
Scientists in Europe have reportedly found a link between the AstraZeneca-Oxford COVID-19 vaccine and extremely rare but potentially fatal blood clots, but Canadian public health officials have so far provided no update on guidance for the shot.
News broke on Friday that researchers in Germany and Norway said they had found a mechanism that could cause the AstraZeneca-Oxford vaccine to create the blood clots in very rare circumstances, in addition to identifying a possible treatment for it.
The finding comes after the European Medicines Agency (EMA) investigated 25 cases of the rare blood clots out of about 20 million AstraZeneca shots given and concluded on Thursday that the benefits from the vaccine far outweigh its possible risks, although a definitive link could not be ruled out.
The EMA said there was no increased risk from blood clots and that because the AstraZeneca-Oxford vaccine is effective in preventing COVID-19, which itself causes blood clots, the shot could actually reduce the risk of them overall.
But not all blood clots are the same, and 18 of the cases in Europe were of an extremely rare type called cerebral venous sinus thrombosis (CVST) — where veins that drain blood from the brain are obstructed and can potentially cause fatal bleeding.
Most of the incidents occurred within 14 days of receiving the AstraZeneca shot, and the majority were in women under the age of 55. It's worth noting that this type of blood clot is much more common in women, particularly during and after pregnancy and while on birth control.
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More than 240 reports of blood clots in U.K. from British AstraZenica COVID-19 vaccine
U.K. to offer adults under 40 alternative vaccines to AstraZeneca-Oxford over blood clot concerns
People under 40 in Britain will no longer be given the AstraZeneca-Oxford coronavirus vaccine if another shot is available because of a link to rare, but serious, blood clots, the government said Friday.
It said the change would not affect the goal of giving all U.K. adults at least one vaccine dose by July.
The Joint Committee on Vaccination and Immunization (JCVI) said people aged 30 to 39 without underlying health conditions should receive an alternative vaccine "where available and only if this does not cause substantial delays in being vaccinated."
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Death of a test subject in AstraZenica COVID-19 vaccine trial.
The test involved giving one group the covid vaccine and the other group a meningitis vaccine. It's not clear which group the subjct that died belonged to.
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A number of countries, including Denmark and Norway, suspended use of the Oxford-AstraZeneca Covid-19 vaccine.
The suspension followed reports that a small number of people had developed clots after receiving the vaccine.
There were also reports that a 50-year-old man had died in Italy after developing deep vein thrombosis (DVT) following a dose of the jab.
"There is currently no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine," the European Medicines Agency (EMA) said on Thursday.
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"All of the vaccinated monkeys treated with the Oxford vaccine became infected"
All of the vaccinated monkeys treated with the Oxford vaccine became infected when challenged, as judged by recovery of virus genomic RNA from nasal secretions. There was no difference in the amount of viral RNA detected from this site in the vaccinated monkeys as compared to the unvaccinated animals. Which is to say, all vaccinated animals were infected. This observation is in marked contrast to the results reported from Sinovac trial. At the highest dose studied, no virus was recovered from vaccinated monkeys from the throat, lung, or rectum of the vaccinated animals.
There is a second troubling result of the Oxford paper. The titer of neutralizing antibody, as judged by inhibition of virus replication by successive serum dilutions as reported is extremely low. Typically, neutralizing antibodies in effective vaccines can be diluted by more than a thousand fold and retain activity. In these experiments the serum could be diluted only by 4 to 40 fold before neutralizing activity was lost. Again, by contrast the titer of neutralizing antibodies in the serum of those vaccinated with whole inactivated SARS-CoV-2 was high.
What then is the argument for pressing forward with the adenovirus vector SARS-CoV-2 spike protein vaccine?
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Covid: France restricts AstraZeneca vaccine to under-65s
The French health authority has said AstraZeneca's Covid-19 vaccine should only be given to people aged under 65.
It is the latest recommendation from an EU member state approving the jab with such restrictions, citing insufficient data on its efficacy for older people.
The EU drugs regulator has approved the Oxford-AstraZeneca vaccine for all adults, but it is up to each member to set its own rollout policy.
Germany and Austria have already recommended it be limited to under-65s.
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Germany's vaccine committee said the AstraZeneca vaccine should only be given to people aged under 65
Dr Mary Ramsay of PHE said the jab offers "high levels of protection" against Covid-19, particularly against severe illness.
Boris Johnson said he was not concerned by Germany's recommendation.
AstraZeneca said the jab's trial data supported efficacy in the over-65s.
Germany's vaccine committee said the AstraZeneca vaccine should only be given to people aged under 65, citing a lack of sufficient data to recommend use among older age groups.
The European Medicines Agency (EMA) is to decide on Friday whether to approve the vaccine for use across the EU.
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South Korea rules out giving AstraZeneca vaccine to over-65s
The Korea Disease Control and Prevention Agency (KDCA) announced on Monday that it will not give the AstraZeneca Covid-19 vaccine to individuals over the age of 65 due to a lack of data.
The KDCA has refused to endorse giving the AstraZeneca vaccine to elderly individuals as it awaits the company’s full clinical trial results, because officials currently fear there is not enough data about its effectiveness and impact in older recipients.
The decision marks a slight reversal from last week’s statement by South Korean Vice Health minister Kim Gang-lip, who said that over-65s would receive the AstraZeneca vaccine, but that a “precautionary line for cautious decision” would be added before the shots were given to elderly people.
The AstraZeneca drug was the first Covid-19 jab to be approved in the country, so its inability to be used in over-65s throws the country’s vaccination program into chaos, as healthcare workers and elderly residents were set to be first in line to get inoculated.
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Health Canada waiting on more data before making a decision on AstraZeneca vaccine
Health Canada says it still needs more information before it can make a decision on the AstraZeneca-Oxford COVID-19 vaccine — news that came after the United Kingdom became the first country to authorize the vaccine.
In a statement released Wednesday, Canada's independent regulator said it's been reviewing the manufacturer's vaccine information since Oct. 1 and as new data roll in.
"There is still information and data to be provided by AstraZeneca for review," says the statement.
"Health Canada cannot provide a definite timeline for the completion of the review at this time."
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Creators of Russia’s Sputnik V Covid-19 vaccine sign Putin-backed deal with UK pharma giant AstraZeneca in bid to boost efficacy
Scientists at Moscow’s Gamaleya Institute signed a memorandum of understanding with British firm AstraZeneca on Monday, signaling the start of cooperation between the two in the fight against the coronavirus.
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What has caused particular concern with these Oxford-AstraZeneca vaccine results, however, is the vaccine appeared to have just a "minimal" impact, maybe only around 22%.
Some of the trials for the Novavax and Janssen vaccines, which reported last month, were in South Africa when the variant was circulating widely.
And they worked less well against it than other versions of the virus.
Although, they were still about 60% effective at stopping people developing symptoms.
What has caused particular concern with these Oxford-AstraZeneca vaccine results, however, is the vaccine appeared to have just a "minimal" impact, maybe only around 22%.
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Oxford Covid vaccine has 10% efficacy against South African variant, study suggests
The Oxford/AstraZeneca vaccine offers as little as 10% protection against the Covid variant first seen in South Africa, researchers have suggested.
Scientists who conducted a small-scale trial of the vaccine’s efficacy said it showed very little protection against mild to moderate infection, though they expressed hope that – in theory – it would still offer significant protection against more serious infection.
Prof Shabir Madhi from the University of the Witwatersrand, who led the trial, said that, while the study was small, it was designed to focus on determining whether or not the vaccine had at least 60% efficacy against Covid to any degree of severity.
“The results that we now describe against the variant, the point estimate is 10%. Clearly, that is far off the 60% mark and, even if you had a larger study you are unlikely to get to a vaccine efficacy readout of even 40 or 50%,” he told BBC Radio 4’s Today programme.
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Lisa Stonehouse in Albrta died after receiving the AstraZeneca COVID-19 vaccine; the fatality was confirmed to be linked to “vaccine-induced immune thrombotic thrombocytopenia (VITT).”
An Alberta woman in her 50s has died after receiving the AstraZeneca COVID-19 vaccine.
In a news release issued Tuesday night, Dr. Deena Hinshaw said the fatality was confirmed to be linked to “vaccine-induced immune thrombotic thrombocytopenia (VITT).”
Family confirmed to Global News that the woman who died was 52-year-old Lisa Stonehouse.
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EU suing AstraZeneca over delayed COVID-19 deliveries
AstraZeneca says legal action by EU without merit, will defend itself in court
The European Union's executive branch said Monday that it has launched legal action against coronavirus vaccine-maker AstraZeneca for failing to respect the terms of its contract with the 27-nation bloc.
The AstraZeneca vaccine has been central to Europe's immunization campaign and a linchpin in the global strategy to get vaccines to poorer countries. But the slow pace of deliveries has frustrated the Europeans and they have held the company responsible for partly delaying their vaccine rollout.
European Commission spokesperson Stefan De Keersmaecker said that Brussels launched the legal action against AstraZeneca last Friday "on the basis of breaches of the advance purchase agreement."
He said the reason for the legal action was that "some terms of the contract have not been respected" and that "the company has not been in a position to come up with a reliable strategy to ensure a timely delivery of doses."
AstraZeneca's contract with the EU, which was signed by the Commission on behalf of the member countries last August, foresaw an initial 300 million doses for distribution among member countries, with an option for a further 100 million.
The British-Swedish drugmaker had hoped to deliver 80 million doses in the first quarter of 2021, but only 30 million were sent. According to the Commission, the company is now set to provide 70 million doses in the second quarter, rather than the 180 million it had promised.
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Coronavirus: EU and AstraZeneca seek to resolve vaccine shortage crisis
AstraZeneca had agreed to deliver millions of doses in January-March but then said significantly fewer jabs would arrive on time. It blamed production problems at European plants.
The EU is demanding the firm divert jabs from the UK.
The UK government has said there "will be no interruption" to UK supply.
Cabinet Minister Michael Gove said it was "critical" to make sure that the "schedule that has been agreed and on which our vaccine has been based goes ahead".
The EU signed a deal with AstraZeneca in August for 300 million doses, with an option for 100 million more, but the UK-Swedish company has reported production delays at plants in the Netherlands and Belgium.
AstraZeneca CEO Pascal Soriot said production was "basically two months behind where we wanted to be".
UK factories have not experienced problems.
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Vaccine developed by AstraZeneca and the University of Oxford has been put on hold over a “potentially unexplained illness” in the United Kingdom
In a statement emailed to Stat News, CNN and CNBC, a spokesperson from AstraZeneca said the company’s “standard review process triggered a pause to vaccination to allow review of safety data.”
“This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials, while it is investigated, ensuring we maintain the integrity of the trials,” the statement reads.
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AstraZeneca/Oxford COVID-19 vaccine trial on pause due to possible serious side effect - neurological symptoms associated with a spinal inflammatory disorder called transverse myelitis
The trial was a Phase 3 clinical trial for a vaccine being developed by the University of Oxford and pharmaceutical company AstraZeneca.
" What kind of illness was it?
AstraZeneca said Wednesday that the patient had neurological symptoms associated with a spinal inflammatory disorder called transverse myelitis, but a final diagnosis was still pending as more tests are carried out, Reuters reported.
That involves localized inflammation of the spinal cord, which can cause symptoms such as weakness, loss of sensation or even paralysis of the arms and legs. It can be caused by autoimmune diseases, viral, bacterial or fungal infections or parasites, but it has also been reported as potentially a rare side effect of vaccinations for diseases such as hepatitis B, influenza or measles-mumps-rubella."
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“Vaccine-Induced Covid-19 Mimicry” Syndrome:
Splice reactions within the SARS-CoV-2 Spike open reading frame result in Spike protein variants that may cause thromboembolic events in patients immunized with vector-based vaccines
During the last months many countries have started the immunization of millions of people by using vector-based vaccines. Unfortunately, severe side effects became overt during these vaccination campaigns: cerebral venous sinus thromboses (CVST), absolutely rare under normal life conditions, were found as a severe side effect that occured 4-14 days after first vaccinations. Besides CVST, Splanchnic Vein Thrombosis (SVT) was also observed. This type of adverse event has not been observed in the clinical studies of AstraZeneca, and therefore led immediately to a halt in vaccinations in several european countries. These events were mostly associated with thrombocytopenia, and thus, similar to the well-known Heparin-induced thrombocytopenia (HIT). Meanwhile, scientists have proposed a mechanism to explain this vaccine-induced thrombocytopenia. However, they do not provide a satisfactory explanation for the late thromboembolic events. Here, we present data that may explain these severe side effects which have been attributed to adenoviral vaccines. According to our results, transcription of wildtype and codon-optimized Spike open reading frames enables alternative splice events that lead to C-terminal truncated, soluble Spike protein variants. These soluble Spike variants may initiate severe side effects when binding to ACE2-expressing endothelial cells in blood vessels. In analogy to the thromboembolic events caused by Spike protein encoded by the SARS-CoV-2 virus, we termed the underlying disease mechanism the “Vaccine-Induced Covid-19 Mimicry” syndrome (VIC19M syndrome).
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Quebec confirms 9th case of vaccine-induced blood clot
Patient is recovering at home
A ninth Quebecer has suffered from vaccine-induced immune thrombotic thrombocytopenia, a rare blood-clotting syndrome, after receiving their first dose of the AstraZeneca-Oxford vaccine, the province's Health Ministry announced Tuesday.
Approximately one in 50,000 people receiving their first shot may get a blood clot, the ministry says.
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Brits given AstraZeneca jab could be blocked from EU holidays
AS MANY as five million Brits could face being blocked from travelling in countries in the European Union, according to reports.
The concern comes this summer because their AstraZeneca vaccines are reportedly not recognised by the EU.
Some vaccine jabs are not recognised in the EU it has been claimed and AstraZeneca jabs administered in the UK currently do not qualify for the EU’s passport scheme as they were manufactured in India.
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