Early data comparing the 2 UK approved vaccines
Gerry Gajadharsingh writes:
“Early data is suggesting there may well be a difference regarding immunity after receiving the first dose of the two different vaccines currently approved and available in the UK.
Despite the EU’s attempt to discredit the Oxford Astrazeneca vaccine, including the UK strategy to increase the interval between the first and the second dose to up to 12 weeks, recent research is suggesting better immunity is achieved after the first dose of this vaccine including the elderly population. The UK government is correct to just let the science do the talking and do not engage with what many people regard as political statements from the EU regarding the Oxford Astrazeneca vaccine. Highly volatile statements below recently released, are not helpful, perhaps as more data emerges they will regret saying:
Ursula von der Leyen, president of the European Commission, suggested that Britain had failed its “gigantic responsibility” when approving vaccines.
France followed Germany yesterday in opting not to use the Oxford/Astrazeneca vaccine in over-65s because of a lack of data after President Macron claimed it was “quasi-ineffective” in this age group. Clément Beaune, his Europe minister, said Britain was taking “many risks in this vaccination campaign”.
Hot on the heels of the positive data regarding the Oxford Astrazeneca vaccine is negative data regarding a poor immune response after the first dose of the Pfizer biotech vaccine in the elderly population.
So what is the headline:
Pfizer Biontech
The seven individuals who were unable to neutralise the virus after the first dose were all aged over 80. This accounts for almost half of the 15 participants in this age group. However, at a follow-up visit after these individuals had received their second dose, given at three weeks, they were all able to neutralise the virus.
The professor and his team have suggested that rapid antibody tests could be used to identify older people who have responded less well to the initial jab and who should be prioritised for the booster shot.
Oxford/Astrazeneca
The Oxford vaccine provides about 75 per cent protection against the coronavirus and significantly reduces its spread after only one jab, suggests a new study that has raised hopes over the lifting of lockdown.
The overall findings were based on trials that involved 17,000 people in the UK, Brazil and South Africa, about half of whom received the real vaccine while the rest were given a placebo. Twenty-one days after they received their first injection there were no hospital admissions in the vaccine group while there were 15 in the control group
Professor Andrew Pollard of Oxford University, who led the vaccine trial, said that the new data “supports the policy recommendation made by the Joint Committee on Vaccination and Immunisation for a 12-week prime-boost interval”
On 16th July 2020 my blog flagged up the Oxford Astrazeneca vaccine as the one to watch
http://www.thehealthequation.co.uk/coronavirus-vaccine-hopes-raised-by-success-of-early-trials/
My takeaway:
“You do not get a choice of vaccine currently in the UK.
If you have received a first dose of the Pfizer BionTech I hope the government will bring forward the second dose in a much quicker time frame than the current suggested 12 weeks.
If you have received a first dose of the Oxford Astrazeneca vaccine then actually waiting to the recommended 12 weeks may well prove beneficial.
As far as I’m aware the NHS is not planning to carry out mass antibody testing on the population they are simply looking at infection rates and hospitalisation rates and death rates post vaccine. Of the small studies that have used antibodies I’m unsure as to which antibodies they are concentrating on. We are using the new Roche spike protein Ab which is appropriate for those who actually had COVID-19 and for those receiving vaccinations. Our initial data does indeed back up what the above research has found.”
Single dose of Pfizer biotech vaccine may not protect elderly from COVID-19 infection
Rhys Blakley
The Times
A significant proportion of people over 80 may have only a “poor” immune response after a single dose of the Pfizer-Biontech vaccine, researchers have said.
Three weeks later, one jab did not always produce the level of antibodies thought to be necessary to block infection. A second dose did lift them above this threshold, however.
Professor Ravi Gupta of Cambridge University, who led the study, said that there was also anecdotal evidence that jarred with assurances from government advisers about the level of protection offered by one dose. He knew of two cases where people who had been vaccinated had later been admitted to hospital.
“Certainly here in Cambridge we are seeing people who have been vaccinated coming into hospital with Covid-19 confirmed,” he said.
The cases involved older people who were admitted to Addenbrooke’s Hospital in Cambridge, despite having been given the injection several weeks earlier. “You should have protection [by then], based on what we were told,” Gupta added. “It may just be the tip of the iceberg . . . It’s important to know that we are seeing cases who have had vaccines.”
The professor and his team have suggested that rapid antibody tests could be used to identify older people who have responded less well to the initial jab and who should be prioritised for the booster shot. Their study, which is yet to be peer-reviewed, looked at 23 people, who had an average age of 82.
Seven, all over the age of 80, had what was described as a “poor response” to a single vaccine dose.
The study did not show whether these people would have developed serious disease. “They might still get a much milder disease and they may not get very sick. We can’t say anything about severity, but they could get infected,” Gupta said.
A separate study, also led by Gupta, explored how well the Pfizer vaccine is likely to perform against different varients. The research involved blood samples from 26 people, aged between 29 and 89, who had received their first dose of the Pfizer vaccine three weeks earlier. Serum, which contains antibodies raised in response to the vaccine, was extracted.
The researchers created a synthetic version of the coronavirus, a “pseudovirus”, bearing the eight mutations found in the Kent strain, which is also known as B1.1.7. When they tested the serum against this pseudovirus, all but seven of the individuals had levels of antibodies sufficiently high to neutralise the virus — that is, to protect against infection.
However, when the E484K mutation, found in the South African variant, was added to the pseudovirus, substantially higher levels of antibodies were required. It emerged today that the same mutation, which changes the structure of the virus’s spike protein, has also been seen in some versions of the Kent variant.
Gupta said: “Our findings suggest that the Pfizer-Biontech vaccine is likely to offer similar protection against B1.1.7 as it does against the previous strain of SARS-CoV-2 [coronavirus]. Although we found a reduction in the ability of antibodies to neutralise the virus, given the number of antibodies produced following vaccination, this should still only have a relatively modest effect and people should still be protected.
“Of particular concern, though, is the emergence of the E484K mutation, which so far has only been seen in a relatively small number of individuals. Our work suggests the vaccine is likely to be less effective when dealing with this mutation.”
He added: “B1.1.7 will continue to acquire mutations seen in the other variants of concern, so we need to plan for the next generation of vaccines to have modifications to account for new variants. We also need to scale up vaccines as fast and as broadly as possible to get transmission down globally.”
The seven individuals who were unable to neutralise the virus after the first dose were all aged over 80. This accounts for almost half of the 15 participants in this age group. However, at a follow-up visit after these individuals had received their second dose, given at three weeks, they were all able to neutralise the virus.
Dr Dami Collier, the main co-investigator on the studies, said: “Our data suggest that a significant proportion of people aged over 80 may not have developed protective neutralising antibodies against infection three weeks after their first dose of the vaccine. But it’s reassuring to see that after two doses, serum from every individual was able to neutralise the virus.” The second study has also not yet been peer-reviewed.
Dr Jonathan Stoye of the Francis Crick Institute, who was not involved in the research, said that it suggested that “some elderly individuals make relatively low immune responses to a single dose of vaccine” and that this may help create vaccine-resistant variants of the virus.
He said: “This raises the possibility that, in some individuals, vaccine-elicited immune responses may be too low to completely block virus replication but high enough to drive selection of resistant viruses. In other words that sub-optimal levels of antibody are driving virus evolution.”
Azra Ghani, chair in infectious disease epidemiology at Imperial College London, said: “With the South African variant now in the UK, it will be important to ensure that the most vulnerable groups are fully protected by the second dose. Given the high coverage of first doses that has now been achieved in the first four priority groups coupled with the very strong age-gradient in risk, this would be a good point at which to switch to scheduling second doses alongside continuing the wider roll-out of first doses to the next priority groups.”
Single dose of Oxford vaccine does reduce spread of Covid
Rhys Blakley, Chris Smyth, Tom Whipple, Bruno Waterfield
The Times
The Oxford vaccine provides about 75 per cent protection against the coronavirus and significantly reduces its spread after only one jab, suggests a new study that has raised hopes over the lifting of lockdown.
The single dose eliminates severe illness among those who contract the virus, according to the results, which have been taken as a vindication of Britain’s strategy.
It also appears to have a “substantial” effect on transmission of the virus. Ministers regard this as a hopeful sign that mass vaccination can speed the lifting of restrictions because not only are people less likely to become ill once they have had the vaccine, they are also less likely to get infected and pass on the virus.
After several European Union leaders cast doubt on Britain’s strategy of prioritisng the first dose, the new analysis of the Oxford-Astrazeneca vaccine trial suggests to the contrary that a 12-week delay improves results.
Matt Hancock, the health secretary, said: “This is a hugely encouraging study and further reinforces our confidence that vaccines are capable of reducing transmission and protecting people from this awful disease. This report shows the Oxford vaccine works and works well.”
Britain is the only country to disregard recommendations for a three-to-four week gap between doses, instead delaying the second for up to 12 weeks in order to reach as many vulnerable people as possible
The new study, which is under peer review and is expected to be published in The Lancet, concludes that leaving a 12-week gap between shots “may be the optimal for roll-out of a pandemic vaccine when supplies are limited in the short term”. Professor Andrew Pollard of Oxford University, who led the vaccine trial, said that the new data “supports the policy recommendation made by the Joint Committee on Vaccination and Immunisation for a 12-week prime-boost interval”. The findings were a reassurance that people “are protected from 22 days after a single dose of the vaccine”, he added.
No one who had received the vaccine developed serious illness after this point, which is roughly when the immune system is thought to have built up protection.
The overall findings were based on trials that involved 17,000 people in the UK, Brazil and South Africa, about half of whom received the real vaccine while the rest were given a placebo. Twenty-one days after they received their first injection there were no hospital admissions in the vaccine group while there were 15 in the control group. After a second dose vaccine efficacy was about 82 per cent with the three-month interval between shots that is being used in the UK. This rose from 55 per cent with an interval of less than six weeks.
The longer gap between doses has become a focus of criticism among EU leaders seeking to defend a slow start to European vaccination programmes.
Ursula von der Leyen, president of the European Commission, suggested that Britain had failed its “gigantic responsibility” when approving vaccines.
France followed Germany yesterday in opting not to use the Astrazeneca vaccine in over-65s because of a lack of data after President Macron claimed it was “quasi-ineffective” in this age group. Clément Beaune, his Europe minister, said Britain was taking “many risks in this vaccination campaign”.
Ministers have been told to avoid retaliating and to focus on evidence that Britain’s approach is justified. Nadhim Zahawi, the vaccines minister, said that the latest study “further reinforces our confidence that vaccines work and protect our most vulnerable from this awful disease.” The report also suggests that the vaccine could dramatically reduce transmission. The authors said it could have a “substantial impact on transmission by reducing the number of infected individuals in the population”. Infected people can shed the virus even if they do not have symptoms.
Ministers cautioned that results from further government studies would need to confirm the new data before decisions were taken on dates for easing the lockdown.
Professor Paul Hunter, of the University of East Anglia, said: “The 12-week gap between first and second dose is clearly the better strategy as more people can be protected more quickly and the ultimate protective effect is greater.” He said that although the vaccine would not prevent people passing on the virus altogether “it will still go a long way to reduce the R value and transmission”. Other scientists cautioned that there were shortcomings in how the trials were run. The figures for the effectiveness of one dose relied on a subgroup of Brazilian volunteers who were relatively young, more likely to be female and more likely to be white than those who received two doses, noted Professor Azra Ghani, of Imperial College London, who was not involved in the study.
Oxford said that its team hoped to report data on how effective the vaccine was at tackling new variants of the virus within days.
Analysis
Forget, for a moment, the exact numbers, the ongoing international contest about which vaccine is up, which vaccine is down and where Oxford-Astrazeneca ranks in that beauty pageant (Tom Whipple writes). We have been told that, thanks to new data, we know a single dose gives people 76 per cent protection from illness for 12 weeks and stops 67 per cent of infections.
Although the numbers come with error bars — the statistical hedging of bets — and from a trial that was not explicitly designed to assess the effects of spacing the doses, the most important information is that the single dose works. People’s immune protection gets stronger and stays strong over the first 12 weeks. People who have had the jab can be confident that they will not lose immunity over the winter.
Another important finding is that the vaccine makes a big dent in transmission. With one and two doses alike, symptomatic cases are cut by a lot and, rather than rising, asymptomatic cases are perhaps cut by a little.