Pfizer

Majority of Covid Hospital Admissions Over Winter Were Vaccinated, PHE Study Shows

The Government announced results from two new vaccine studies from Public Health England (PHE) yesterday. One looks at how much protection the vaccines offer against death once a person is infected, the other at how much protection against hospitalisation with COVID-19 the vaccines offer.

The study on deaths is the more straightforward of the two. It looks at PCR positive cases in England between December 8th and April 6th. It finds among 80+ year-olds: 16.1% (1,462/9,105) of unvaccinated cases died versus 9.2% (99/1,072) of cases at least 21 days after their first Pfizer dose, 11.3% (33/293) of cases at least 21 days after their first AstraZeneca dose and 4.7% (6/128) of cases at least seven days after their second Pfizer dose. These correspond to unadjusted relative risk reductions of 43% (Pfizer 1), 30% (AZ 1) and 71% (Pfizer 2) respectively.

Among 70-79 year-olds it finds 4.0% (1,147/28,875) of unvaccinated cases died versus 2.7% (15/549) for Pfizer 1, 2.1% (10/484) for AZ 1 and 0% (0/7) for Pfizer 2. This corresponds to unadjusted relative risk reductions of 33% (Pfizer 1), 47% (AZ 1) and 100% (Pfizer 2).

Once adjusted for sex, clinical risk factors, age and being a care home resident, these become relative risk reductions of 44% (Pfizer 1), 55% (AZ 1) and 69% (Pfizer 2). This level of reduction in the mortality rate among the vaccinated over-70s once infected is encouraging. The lack of data on deaths within 21 days of the first jab and seven days of the second jab is disappointing. Why do we have yet another study on vaccine efficacy with no accompanying analysis of safety?

The second study looks at whether vaccination protects against hospitalisation. Unlike the first study, it doesn’t look at those already infected (testing positive) to see whether they are hospitalised, but at those who are hospitalised to see whether they’ve been vaccinated. It analyses 13,907 admissions in trusts participating in a surveillance programme between December 8th and April 18th. It excludes those who caught the virus in hospital. It also excludes those whose positive PCR test was more than five days before admission (1,230 cases), the reason for which is not explained. The breakdown of admissions by sex, age and vaccination status is shown in the table below.

Notice that a majority of admissions in this period – 57% – had received at least one vaccine dose. An earlier study that I noted before, from the ISARIC4C consortium, had found just 7.3% of hospital admissions over a similar period had received at least one vaccine dose. The reasons for this huge discrepancy are unclear, but given that the earlier figure made headlines for showing how effective the vaccines are, and for the sake of clarity in data, it should be cleared up.

Study Claims Pfizer Vaccine is 95% Effective in Over 65s. But Should That Be 74%?

A new population study from Israel, published in the Lancet on Wednesday, finds that the Pfizer vaccine is 95.3% effective against SARS-CoV-2 infection once a person is fully vaccinated (defined as being a week past their second dose). It also finds the vaccine is 94.8% effective in those aged 65 or older once fully vaccinated.

This is in line with other studies and is a very encouraging result. However, as with previous studies, it’s not clear how well the researchers have taken into account the fact that infections were declining anyway during the study period and whether this has led to an over-estimation of vaccine effectiveness.

To test this I accessed the data available from the Israeli Government. I looked at how many cases occurred in each age group each week alongside the proportion of that age group that had been fully vaccinated by that week. This allowed me to calculate how many infections we would expect to occur among vaccinated people in each age group each week if you assume the vaccines don’t have any effect. I then added these together to give a baseline number of cases in each age group to compare against the number of actual cases among the vaccinated as reported in the study. The results are shown below.

I calculated we would expect 43,826 infections among the vaccinated out of a total of 237,700 in the study period (January 24th to April 3rd) if the vaccines have no effect, which is 18.4%.

The study reports 6,266 infections among the vaccinated out of a total of 232,268 during the study period, or 2.7%. (I wasn’t able to discover why the study had about 2.3% fewer infections than the Israeli Government data broken down by age, but by using proportions we can avoid this discrepancy affecting the calculation.)

A proportion of 2.7% is 85.4% lower than a proportion of 18.4% that we estimated if the vaccines had no effect. This suggests a vaccine effectiveness of more like 85% than 95%.

Looking now at the crucial older age group, if the vaccines had no effect I have calculated we would expect 11,332 infections among the vaccinated aged 60 and over out of a total of 29,489 infections in that age group during the study period. The study found 2,201 infections among the fully vaccinated aged 65 or more. (It doesn’t state how many infections there were in total in this age group so we can’t calculate a straightforward proportion from the study.)

We need to adjust our expected figure of 11,332 to allow for the fact that it includes those aged 60-64 (the study uses different age brackets from the publicly available Government data). From the table above this will be about half of the infections in the 60-69 age group, or 2,834. We also need to reduce the expected figure by around 2.3% to allow for the different infection totals of the study and Government data. This gives us an expected figure of 8,329 infections among the vaccinated over 65s.

The 2,201 figure from the study is 73.6% smaller than 8,329, suggesting a vaccine effectiveness among the over 65s of more like 74% than 95%.

It’s not clear why the authors of the study did not do an analysis similar to this one. Taking into account the background prevalence of the virus should be basic, to avoid over-estimating the effectiveness of vaccines when they are rolled out during the decline of the epidemic.

The study (which was funded and approved for publication by Pfizer) briefly mentions lower vaccine effectiveness 2-3 weeks after the first dose, but does not give any information about effectiveness or infection incidence in the first 14 days. This means it gives no more information about the post-vaccination infection spike observed in other studies, though the silence here may be telling.

A further question is why the researchers gave no finer-grained detail about those older than 65 when they must have had the data to do so, and more than half of Covid deaths are in those aged over 80.

An effectiveness of 85% overall and 74% among the over 65s is still good, but it is not as good as the 95% figures in the study. As so often with vaccine studies, on closer inspection you’re left wondering whether you’re getting the full and accurate picture.

Canada Authorises Use of Pfizer Covid Vaccine for Children

Canada has become the first country to authorise the use of the Pfizer Covid vaccine on children aged 12 to 15. Many other countries are likely to follow suit. BBC News has the story.

[Canada’s] Health Ministry made the decision based on data from phase three clinical trials on children that age. 

“The department determined that this vaccine is safe and effective when used in this younger age group,” an adviser at the Ministry said. Pfizer says its jab works well in the age group.

Canada has already authorised the use of the Pfizer vaccine in people over 16. 

The state of Alberta, which has the highest rate of the virus in the country, said it would offer vaccines to those over 12 from Monday.

Canada has recorded more than 1.2 million coronavirus cases and roughly 20% of those have been in people under the age of 19. 

The country’s vaccine rollout has been relatively slow, caused by delivery delays. About 34% of people in the country have received at least one dose of the vaccine while the figure in the US stands at 44%, according to Our World in Data…

As part of the vaccine’s approval, Pfizer will have to continue providing information to Canada’s Health Ministry on the safety, efficacy and quality of the vaccine in those aged 12 to 15. 

In March, Pfizer said initial results from trials of its vaccine in this age group showed 100% efficacy and a strong immune response.

U.S. regulators are expected to authorise the use of the Pfizer vaccine in the same age group in the coming days, and in the U.K. the NHS is preparing to vaccinate schoolchildren from September, shortly before those aged over 50 will be offered a third Covid vaccine dose.

The BBC News report is worth reading in full.

Israel Investigating Link Between Pfizer Vaccine and Heart Problem in Men Under 30

The Israeli Health Ministry has raised concerns that there could be a link between the Pfizer Covid vaccine and heart complications, particularly among younger men. There are currently 62 recorded cases in Israel of myocarditis, an inflammation of the heart muscle, which occurred in the days after vaccination. Pfizer responded saying it has not seen similar reports in other countries where the vaccine has been rolled out, though this could be because few other countries have vaccinated as many young people as Israel. The Times of Israel has the story.

Details from an unpublished Israeli Health Ministry report into the side effects of the Pfizer vaccine have raised concerns that there could be a link between the second shot and several dozen cases of myocarditis… particularly in men under 30, Channel 12 reported Friday.

The concerns come from an intermediate report that was presented to ministry heads and to Pfizer in recent weeks, the TV report said. Excerpts from the leaked report stressed that investigators had not conclusively proved a link, but that they had significant concerns.

The report said that out of more than five million people vaccinated in Israel, there were 62 recorded cases of myocarditis in the days after the shot. It found that 56 of those cases came after the second shot and most of the affected were men under 30.

The report said that 60 of the patients were treated and released from hospital in good condition. Two of the patients, who were reportedly healthy until receiving the vaccination, including a 22 year-old woman and a 35 year-old man, died.

“The findings were presented to the Pfizer company who replied that they had not had similar reports in the rest of the world and would examine the data,” an excerpt from the report said, adding that the details had also been sent to the U.S. FDA and CDC, who were also investigating.

The report was authored by senior ministry officials led by Professor Dror Mevorach, head of one of the Covid units at Hadassah Hospital Ein Kerem.

The authors surmised that “one possible reason for lack of similar findings in other countries was the low rate of vaccinations among young people”.

“There is specific concern regarding the frequency of the occurrence observed in men under 30 in the days immediately after the second shot,” they wrote. “At this stage, according to initial findings that still need to be verified, there is an impression that the number (of cases) is higher than would be expected, especially for those under 30.”

The report found that of those who received the second dose, 1 in 100,000 had possible side effects of myocarditis; however, this number rose to 1 in 20,000 among those aged 16-30.

“We cannot yet tell if there are more cases than normal or if there are similar numbers annually and the proximity is just a coincidence. Efforts to collect more data are continuing,” the report said.

This news comes as the E.U. gets closer to signing off on a deal with Pfizer and BioNTech to buy up to 1.8 billion doses of their Covid vaccine. The bloc has come to prefer this vaccine to that produced by AstraZeneca due to a number of factors, some of them political.

The Times of Israel report is worth reading in full.

E.U. Orders 1.8 Billion Doses of Pfizer’s Covid Vaccine

The E.U. will soon seal its rejection of the AstraZeneca Covid vaccine by signing off on the world’s biggest vaccine deal yet, buying up to 1.8 billion doses of the Pfizer and BioNTech vaccine to last until 2023. The Telegraph has the story.

The vaccines from the U.S. drugmaker and its German partner BioNTech would be delivered over 2021-2023, Commission President Ursula von der Leyen said during a visit to Pfizer’s vaccine plant in Puurs, Belgium.

The agreement would be enough to inoculate the 450 million E.U. population for two years and comes as the bloc seeks to shore up long-term supplies.

This is the third contract agreed by the bloc with the two companies, which have already agreed to supply 600 million doses of the two-dose vaccine this year under two previous contracts.

European Commission Chief Ursula von der Leyen said on Friday that the E.U. will have enough to inoculate at least 70% of E.U. adults by the end of July.

The E.U. Chief had previously set a goal of late September.

An E.U. official said the supply deal was agreed in principle but that both sides needed a few days to iron out final terms.

“We will conclude in the next days. It will secure the doses necessary to give booster shots to increase immunity,” Ms von der Leyen said at a briefing at the Puurs factory.

Pfizer has scrambled to boost output in recent months at its U.S. and Belgian plants to meet growing demand.

Pfizer CEO Albert Bourla said Puurs is expected to have the capacity to produce more than 100 million doses by May.

A new study by Oxford University and the ONS has found that one dose of the Pfizer vaccine reduces Covid infections by 65%. The same is true of the AstraZeneca vaccine, according to the study, but many European countries have come to distrust the vaccine because of its link to blood clots (the risk of which has been upgraded in the past two weeks). Thirty three per cent of Danes would refuse to take the AZ vaccine, according to a survey, while in Sicily the refusal rate is said to be closer to 80%. On top of concerns about cases of blood clotting, the European Commission has criticised AstraZeneca for cutting its vaccine deliveries to the bloc and is now preparing legal proceedings against the drugmaker, according to reports. The E.U.’s contract with AZ included 400 million doses of the Covid vaccine, 100 million of which were optional. The bloc, which has tightened its bond with Pfizer, has decided against taking this option up.

The Telegraph’s report is worth reading in full.

Pfizer Vaccine 98% Effective Against Brazilian Variant

A new study – the largest of its kind – has found that the Pfizer vaccine produces an “off the scale” immune response that is likely to protect against the Brazilian variant of COVID-19. The Telegraph has more.

The biggest study on antibody and cellular immune factors to date suggests people are likely to be protected against the Wuhan, Kent and Brazilian types of coronavirus following two doses of the vaccine.

The research, led by the University of Birmingham and including Public Health England’s Porton Down laboratory, found 98 per cent of people aged 80 or over who had two doses of the Pfizer jab had a strong antibody immune response.

Professor Paul Moss, from the University of Birmingham and leader of the UK Coronavirus Immunology Consortium, told a briefing: “We’ve certainly seen in this paper that the antibody levels are so good, really after the first two weeks, that we are pretty confident that this should be very helpful against the Brazilian variant.”

Worth reading in full.

Are the Vaccines Really “62% Effective” For Care Home Residents?

A new study from University College London published yesterday claims to find that a single vaccine dose provides 62% protection against COVID-19 for care home residents.

The Government-funded study looked at data from more than 10,000 care home residents in England with an average age of 86, between December and mid-March, comparing the number of infections occurring in vaccinated and unvaccinated groups (as determined by a PCR test). It found that a single vaccine dose was effective at preventing 56% of infections after four weeks, rising to 62% of infections after five weeks.

It is the first major study to show vaccine efficacy in the most vulnerable, with Minister for Care Helen Whately saying it is “brilliant to see this [vaccine] is having the positive effect the science suggested, not only by preventing death, but also reducing the chance of infection”.

But have we been given the full picture? Below is the table the 62% figure comes from. It’s the 0.38 after 35-48 days (5-7 weeks) among the figures circled in red. The 56% protection is the 0.44 above it.

Notice two things. First, what the story on the UCL website and in newspaper reports doesn’t mention is that the protection figure drops from 62% to 51% (0.49) after seven weeks (circled red), which is somewhat less impressive. Secondly, the infection rate in the three weeks following vaccination rises significantly (circled orange), with the rate at 2-3 weeks hitting 26.21 vs 21.39 in the unvaccinated, a 22.5% increase. As Lockdown Sceptics has reported before, this increased infection rate post-vaccination has also been found in other studies, with a PHE study finding a 48% increase in infection risk in the over-80s group 4-9 days after receiving the first dose of the Pfizer vaccine, the American FDA Emergency Use Authorisation for the Pfizer vaccine finding 40% higher “suspected Covid” in the first week after vaccination, and a large Danish study finding a 40% increase in infection risk among nursing home residents in the 14 days following the first Pfizer dose.