Vaccination has been widely implemented for mitigation of coronavirus disease-2019 (Covid-19), and by 11 November 2022, 701 million doses of the BNT162b2 mRNA vaccine (Pfizer-BioNTech) had been administered and linked with 971,021 reports of suspected adverse effects (SAEs) in the European Union/European Economic Area (EU/EEA).1 Vaccine vials with individual doses are supplied in batches with stringent quality control to ensure batch and dose uniformity.2 Clinical data on individual vaccine batch levels have not been reported and batch-dependent variation in the clinical efficacy and safety of authorized vaccines would appear to be highly unlikely. However, not least in view of the emergency use market authorization and rapid implementation of large-scale vaccination programs, the possibility of batch-dependent variation appears worthy of investigation. We therefore examined rates of SAEs between different BNT162b2 vaccine batches administered in Denmark (population 5.8 million) from 27 December 2020 to 11 January 2022.
A total of 7,835,280 doses were administered to 3,748,215 persons with the use of 52 different BNT162b2 vaccine batches (2340–814,320 doses per batch) and 43,496 SAEs were registered in 13,635 persons, equaling 3.19 ± 0.03 (mean ± SEM) SAEs per person. In each person, individual SAEs were associated with vaccine doses from 1.531 ± 0.004 batches resulting in a total of 66,587 SAEs distributed between the 52 batches. Batch labels were incompletely registered or missing for 7.11% of SAEs, leaving 61,847 batch-identifiable SAEs for further analysis of which 14,509 (23.5%) were classified as severe SAEs and 579 (0.9%) were SAE-related deaths. Unexpectedly, rates of SAEs per 1000 doses varied considerably between vaccine batches with 2.32 (0.09–3.59) (median [interquartile range]) SAEs per 1000 doses, and significant heterogeneity (p < .0001) was observed in the relationship between numbers of SAEs per 1000 doses and numbers of doses in the individual batches. Three predominant trendlines were discerned, with noticeable lower SAE rates in larger vaccine batches and additional batch-dependent heterogeneity in the distribution of SAE seriousness between the batches representing the three trendlines (Figure 1). Compared to the rates of all SAEs, serious SAEs and SAE-related deaths per 1.000 doses were much less frequent and numbers of these SAEs per 1000 doses displayed considerably greater variability between batches, with lesser separation between the three trendlines (not shown).
Author(s): Max Schmeling, Vibeke Manniche, Peter Riis Hansen
Publication Date: 30 Mar 2023
Publication Site: European Journal of Clinical Investigation
The Omicron variant of the coronavirus can partially evade the protection from two doses of Pfizer Inc (PFE.N) and partner BioNTech’s COVID-19 vaccine, the research head of a laboratory at the Africa Health Research Institute in South Africa said on Tuesday.
Still, the study showed that blood from people who had received two doses of the vaccine and had a prior infection were mostly able to neutralize the variant, suggesting that booster doses of the vaccine could help to fend off infection.
Pfizer Inc. and partner BioNTech SE said their Covid-19 vaccine was found to be safe in children ages 5 to 11 years in a late-stage study and generated a strong immune response in them, bringing the prospect of broader vaccination coverage closer.
Pfizer said it would share the results with regulators in the U.S. and other countries and seek emergency-use authorization in the U.S. as early as the end of the month.
The companies said the two-dose shot was found to be safe and well tolerated among the children in the study. The vaccine generated levels of antibodies that were similar to those of younger adults, meeting the study’s measurements of success, according to the companies.
Pfizer and BioNTech said they hadn’t yet determined vaccine efficacy — how well it protects against Covid-19 — for children in the age group. Not enough young subjects in the study have become sick to compare rates between children who got a vaccine and those who got a placebo, but researchers could still learn more as the trial continues.
The UK has four vaccines approved for use: Pfizer-BioNTech, Oxford-AstraZeneca, Moderna and Janssen; three of which require two doses for maximum protection.
The campaign to reach as many people as quickly as possible was boosted by a shift in policy in early January – to prioritise the first dose of a vaccine, with a second dose up to 12 weeks later, a bigger gap than originally planned.
Progress made in the UK so far means the country continues to be among those with the highest vaccination rates globally.
The good news? Vaccines still sharply reduce the risk of being admitted to hospital with the Delta variant. The Scottish study found that the Pfizer/BioNTech vaccine provided 79% protection, two weeks on from the second dose, while the Oxford/AstraZeneca vaccine offered 60% protection. That lower rate may be due to the fact that it takes longer for immunity to develop with the Oxford/AstraZeneca vaccine, researchers said.
However, research released shortly after by Public Health England was even more promising. It found that the Pfizer/BioNTech vaccine provides 96% protection from hospitalization after two doses, while the Oxford/AstraZeneca is 92% effective at preventing hospitalization after both shots. The conclusion? It’s yet more evidence of the importance of making sure as many people as possible get vaccinated, and that they get both shots.
In courtrooms, mixing up the probability of “A given B’” with “B given A” is known as the “prosecutor’s fallacy”. In 1999, a court convicted Sally Clark of the murder of her two sons, in part because a medical expert claimed the chance of two accidental cot deaths was one in 73m. Even if this number was right – which it isn’t – it did not reflect the chance she was innocent. A double murder was also very rare: the relative likelihood of the two explanations was key and with new evidence and better statistical reasoning, an appeal court quashed the conviction.
There was controversy after a recent Observer headline referred to Bayes’s theorem as “obscure”. His ideas may be little known by the public, but they are growing among scientists. Many complex analyses done during the pandemic have been “Bayesian”, including modelling lockdown effects, the ONS infection survey, and Pfizer-BioNTech’s vaccine trial. The term “credible interval”, rather than “confidence interval”, is the giveaway.
Last week, Cass Business School announced the renaming of its institution after Bayes and his theorem. The obscure tomb in nearby Bunhill Fields is worth a visit.
While much of the world is engaged in a frantic scramble to get vaccinated against covid-19, there’s one group noticeably absent from the queues of people at vaccine clinics: children.
The Pfizer-BioNTech vaccine is still approved for use only in those aged 16 years or older, and the Moderna vaccine is only for adults. Both are now in trials for younger age groups, and results are expected by the summer. The Oxford-AstraZeneca and Johnson & Johnson vaccines are also due to start trials in children soon. But in a world where most vaccines are given to children under two, why is it that during a global pandemic, children are being left behind? And what does it mean for how the pandemic will unfold in adults?
One reason children are not yet priorities for vaccination is that they are much less affected by SARS-CoV-2 infection than adults. Children make up nearly 13% of all cases reported in the United States so far, but less than 3% of all reported hospitalizations and less than 0.21% of all covid-19 deaths. When they have symptoms, they are similar to adults’—cough, fever, sore throat, and runny nose—but less severe.
The Covid-19 vaccine from Pfizer Inc. and BioNTech SE is equally effective across all age groups, including those over 60, according to a new Israeli study, in a boost of confidence to global vaccine efforts.
The Pfizer vaccine provided around 94% protection against developing coronavirus symptoms across all age groups above 16 a week after the second shot of a recommended two-dose regimen, according to a study by researchers from Israel’s Clalit Research Institute and Harvard University. The study also found the vaccine is 92% effective in preventing severe disease.
The results are in line with the vaccine maker’s own clinical trial, but the large size of the study, which covered nearly 1.2 million people, provides more precise insight into older age groups that were sparsely covered by the drugmaker’s trial, according to the study’s authors.