Tag: Pfizer

Categories : Cancer GeneticsTags :

mRNA Technology Restores Tumour Suppressor Protein in Ovarian Cancer

On By ModernMedia
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Using mRNA technology developed and matured for certain COVID vaccines, researchers have successfully restored the tumour-suppressing p53 protein in mouse models of advanced human ovarian cancer, significantly extending their survival. They report their results in Cancer Communications.

Ovarian cancer is often only detected at an advanced stage and metastases have already formed — usually in the intestines, abdomen or lymph nodes. At such a late stage, only 20 to 30% of all those affected survive the next five years. “Unfortunately, this situation has hardly changed at all over the past two decades,” says Professor Klaus Strebhardt, Director of the Department of Molecular Gynecology and Obstetrics at University Hospital Frankfurt.

In 96% of all ovarian cancer (high-grade) patients, the tumour suppressor gene p53 has mutated and is now non-functional. The gene contains the building instructions for an important protein that normally recognises damage in each cell’s DNA. It then prevents these abnormal cells from proliferating and activates repair mechanisms that rectify the damage.

If this fails, it induces cell death. “In this way, p53 is very effective in preventing carcinogenesis,” explains Strebhardt. “But when it is mutated, this protective mechanism is eradicated.”

If a cell wants to produce a certain protein, it first makes a transcript of the gene containing the building instructions for it. Such transcripts are called mRNAs. In women with ovarian cancer, the p53 mRNAs are just as defective as the gene from which they were copied.

“We produced an mRNA in the laboratory that contained the blueprint for a normal, non-mutated p53 protein,” says Dr Monika Raab from the Department of Molecular Gynecology and Obstetrics, who conducted many of the key experiments in the study.

“We packed it into small lipid vesicles, known as liposomes, and then tested them first in cultures of various human cancer cell lines. The cells used the artificial mRNA to produce functional p53 protein.”

In the next step, the scientists cultivated ovarian tumours – organoids – from patient cells sourced by the team led by Professor Sven Becker, Director of the Women’s Clinic at University Hospital Frankfurt.

After treatment with the artificial mRNA, the organoids shrank and began to die.

To test whether the artificial mRNA is also effective in organisms and can combat metastases in the abdomen, the researchers implanted human ovarian tumour cells into the ovaries of mice and injected the mRNA liposomes into the animals some time later.

The result was very convincing, says Strebhardt: “With the help of the artificial mRNA, cells in the animals treated produced large quantities of the functional p53 protein, and as a result both the tumours in the ovaries and the metastases disappeared almost completely.”

That the method was so successful is partly due to recent advances in mRNA technology: Normally, mRNA transcripts are very sensitive and degraded by cells within minutes.

However, it is meanwhile possible to prevent this by specifically modifying the molecules.

This extends their lifespan substantially, in this study to up to two weeks.

In addition, the chemical composition of the artificial mRNA is slightly different to that of its natural counterpart.

This prevents the immune system from intervening after the molecule has been injected and from triggering inflammatory responses.

In 2023, the Hungarian scientist Katalin Karikó and her American colleague Drew Weissman were awarded the Nobel Prize in Physiology or Medicine for this discovery.

“Thanks to the development of mRNA vaccines such as those of BioNTech and Moderna, which went into action during the SARS-CoV-2 pandemic, we now also know how to make the molecules even more effective,” explains Strebhardt.

Strebhardt, Raab and Becker are now looking for partners to join the next step of the translational project: testing on patients with ovarian cancer. “What is crucial now is the question of whether we can implement the concept and the results in clinical reality and use our method to help cancer patients,” says Strebhardt. The latest results make him very optimistic that the tide could finally turn in the treatment of ovarian carcinomas. “p53 mRNA is not a normal therapeutic that targets a specific weak point in cancer cells. Instead, we are repairing a natural mechanism that the body normally uses very effectively to suppress carcinogenesis. This is a completely different quality of cancer therapy.”

Source: Goethe University Frankfurt

Categories : COVID VaccinesTags :

Half Dose of COVID Booster Yields Similar Immune Response to Full One

On By ModernMedia
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Reducing the dose of a widely used COVID booster vaccine produces a similar immune response in adults to a full-dose with fewer side effects, according to a new study published in The Lancet Regional Health – Western Pacific. The research found that a half dose of a Pfizer COVID booster vaccine elicited a non-inferior immune response to a full dose in Mongolian adults who previously had AstraZeneca or Sinopharm COVID shots. But it found half-dose boosting may be less effective in adults primed with the Sputnik V COVID vaccine. 

The research, led by Murdoch Children’s Research Institute (MCRI) and the National Centre for Communicable Diseases in Mongolia, is part of an international clinical trial investigating the different COVID booster shot approaches to help guide future vaccination strategies. 

The first batch of findings, and involving 601 participants over 18 years old from Mongolia, reports on the initial responses seen 28-days after vaccination. The study is the first of its kind to assess and compare COVID-19 vaccines widely used in low- and middle-income countries.

MCRI Professor Kim Mulholland, who also sits on the WHO SAGE committee, said the study found that fractional doses elicited an immune response that was non-inferior to a full dose with fewer side effects and was less costly.

“Fractional dosing may improve COVID booster acceptability and uptake and reduce the per-dose cost of COVID-19 booster programs,” he said. “Policymakers and immunisation advisory committees can draw upon this data to make flexible boosting schedules decisions.”

The study found that participants receiving a half dose reported fewer local reactions than those receiving full doses (60% versus 72%) including less pain and tenderness. They also reported fewer systemic reactions (25% vs 32%) including less fevers, vomiting, diarrhoea and headaches. 

The cohort will be followed up at six and 12 months with the data to answer key questions on other aspects of the immune response including the rate of waning and breakthrough infections. 

Source: Murdoch Children’s Hospital

Categories : Obstetrics & Gynaecology VaccinesTags :

Preterm Births Concern Raised Over New Maternal RSV Vaccine

On By ModernMedia

Experts have called for further scrutiny of a new Pfizer vaccine given during pregnancy to prevent respiratory infection in infants, after trials of a similar GSK vaccine were stopped after increased preterm birth and infant deaths. Pfizer says its vaccine is safe and effective, but experts contacted as part of an investigation published by The BMJ say that Pfizer’s trial data should be reviewed in light of the trend for preterm births seen in GSK’s trial.

Pfizer’s maternal RSV vaccine aims to protect infants from severe illness caused by the respiratory syncytial virus (RSV). RSV is very common but can be fatal, especially in young children. In 2019, an estimated 3.6% of all deaths worldwide in children aged 1-6 months were due to RSV, with 97% of these deaths occurring in low and middle income countries.

The vaccine has not yet been approved for use, but a decision by the US Food and Drug Administration is expected by August. The European Medicines Agency is also set to make a decision about the vaccine later this year.

In February 2022, GSK halted vaccination in its phase 3 trials of its maternal RSV vaccine after finding an increased risk of preterm birth in vaccinated mothers, mainly in low and middle income countries.

Pfizer published the results of an interim analysis of its phase 3 trial last month, saying that the vaccine was effective against medically attended severe RSV in children and that no safety concerns were identified.

And while the difference in preterm births in the Pfizer trials was not statistically significant, the results have raised concerns about a possible increase in preterm births, and now experts are calling for further analyses of the data and post-approval monitoring of the vaccine should the FDA approve it.

“My interpretation of all these data is that there may be a safety signal for preterm births that should be followed up on,” said Klaus Überla, director of the Virological Institute of the University Hospital Erlangen and member of the RSV working group of the Standing Committee on Vaccination (STIKO), which develops national recommendations for the use of licensed vaccines in Germany. 

And a scientist at the National Institutes of Health (NIH) said the Pfizer data should be analysed using more sensitive measures such as average birth weight and subgroup analyses to detect possible signals.

Meanwhile, Cody Meissner, professor of paediatrics and medicine at the Dartmouth Geisel School of Medicine and consultant in the US Centers for Disease Control and Prevention (CDC)’s maternal RSV working group, predicts that possible adverse effects such as premature births will be “closely monitored” in assessment programs by FDA and CDC.  “We need a safe vaccine,” he added.

Pfizer did not respond when asked about a possible increase in preterm births associated with its vaccine, but told The BMJ that “no imbalance of neonatal deaths was observed” in its phase 3 trial. 

In a linked editorial, researchers point to challenges for RSV vaccine development and the main approaches to protection currently being pursued. 

They argue that, while the burden of illness caused by RSV is substantial worldwide, it is particularly important that new vaccines and other prevention strategies are available to infants in low and middle income countries, where the greatest illness and deaths occur.

And they say further research is urgently needed “to identify the best prevention strategies for low and middle income countries, where affordability is paramount and timing of administration is complicated by the lack of predictable seasonal RSV epidemics.”

Source: EurekAlert!

Categories : COVID Obstetrics & GynaecologyTags :

EU Adds Heavy Menstrual Bleeding as Side Effects of Comirnaty and Spikevax

On By ModernMedia
Covid vaccines
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The European Medicines Agency (EMA) recommended that heavy menstrual bleeding should be added to the product information as a side effect of unknown frequency of the mRNA COVID vaccines Comirnaty (Pfizer/BioNtech) and Spikevax (Moderna).

Heavy menstrual bleeding may be defined as bleeding characterised by an increased volume and/or duration which interferes with the person’s physical, social, emotional and material quality of life. Cases of heavy menstrual bleeding have been reported after the first, second and booster doses of Comirnaty and Spikevax.

The EMA’s Pharmacovigilance Risk Assessment Committee (PRAC) assessed this safety signal after reviewing the available data, including cases reported during clinical trials, cases spontaneously reported in Eudravigilance and findings from the medical literature.

After a review of the available data, the PRAC concluded that there is at least a reasonable possibility that the occurrence of heavy menstrual bleeding is causally associated with these vaccines and therefore recommended the update of the product information.

The available data reviewed involved mostly cases which appeared to be non-serious and temporary in nature.

There is no evidence to suggest the menstrual disorders experienced by some people have any impact on reproduction and fertility. Available data provides reassurance about the use of mRNA COVID vaccines before and during pregnancy. A review carried out by EMA’s Emergency Task Force showed that mRNA COVID vaccines do not cause pregnancy complications for expectant mothers and their babies, and they are as effective at reducing the risk of hospitalisation and deaths in pregnant people as they are in non-pregnant people.

Source: European Medicines Agency

Categories : COVIDTags :

mRNA Vaccines Perform Better against Variants of Concern

On By ModernMedia
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A comparison of vaccinations has demonstrated that mRNA vaccines perform better against variants of concern (VOCs) than viral vector vaccines. Although they all effectively prevent severe disease by VOCs, the research published in PLOS Medicine suggests that people receiving a viral vector vaccine are more vulnerable to infection by new variants.

The Pfizer-BioNTech and Moderna are mRNA vaccines, which deliver genetic code to the bodies’ cells, whereas Oxford/AstraZeneca and J&J are viral vector vaccines which uses a modified virus to deliver instructions. J&J is delivered as a single dose while the rest are administered two weeks apart.

Marit J. van Gils at the University of Amsterdam, Netherlands, and colleagues, took blood samples from 165 healthcare workers, three and four weeks after first and second vaccination respectively, and for J&J at four to five and eight weeks after vaccination. Samples were collected before, and four weeks after a Pfizer-BioNTech booster.

Four weeks after the initial two doses, antibody responses to the original SARS-CoV-2 viral strain were highest in recipients of Moderna, followed closely by Pfizer-BioNTech, and were substantially lower in those who received viral vector vaccines. Tested against the VOCs Alpha, Beta, Gamma, Delta and Omicron, neutralising antibodies were higher in the mRNA recipients than the viral vector recipients. Neutralisation ability against VOCs was reduced in all vaccine groups, with the greatest reduction against Omicron. The Pfizer-BioNTech booster increased antibody responses in all groups with substantial improvement against VOCs, including Omicron.

The researchers caution that their AstraZeneca group was significantly older, because of safety concerns for the vaccine in younger age groups. As immune responses tend to weaken with age, this could affect the results. This group was also smaller because the Dutch government halted use for a period.

Source: EurekAlert!

Categories : COVIDTags :

Two Doses of Pfizer or J&J Vaccine are Effective vs Severe Omicron

On By ModernMedia
Image of a syring for vaccination
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A South African-led study published in the New England Journal of Medicine has shown that two doses of the Pfizer or the Johnson and Johnson (J&J) vaccine are equally effective against severe COVID caused by the omicron variant.

The omicron variant has been shown to escape antibody neutralisation by both the Pfizer/BioNTech mRNA and the Johnson & Johnson adenovirus viral vector vaccine, the only two COVID vaccines available in South Africa. As of May 1, 44.8% of adults in South Africa had been fully vaccinated. Assessing vaccine effectiveness is critical for national vaccine programs.

Starting in October 2021, health care workers who were participating in phase 3b of the Sisonke study of the early vaccine access program were eligible to receive a second dose of the J&J vaccine. Discovery Health data was accessed for Pfizer vaccine effectiveness. Severe COVID was defined as hospitalisation or admission to an intensive care unit (ICU) or to high care.

Vaccine effectiveness was compared between the two vaccine groups according to the number of days since the second vaccine dose had been administered. However longer follow-ups were not available for the J&J group as booster had been initiated later for them.

PCR results were analysed from participants who had received two doses of the Pfizer vaccine given at least 42 days apart or two doses of the J&J vaccine given 4 to 6 months apart. Among these participants, the test positivity rate was 34%; of those with a positive PCR test, 1.6% had been admitted to a hospital and 0.5% to an ICU or to high care.

Effectiveness against hospitalisation in the J&J group, was found to be 55% within 13 days after the second dose, 74% at 14 to 27 days, and 72% at 1 to 2 months. For the Pfizer group, the vaccine’s effectiveness was 81% within 13 days after the second dose, 88% at 14 to 27 days, 70% at 1 to 2 months, 71% at 3 to 4 months, and 67% at > 5 months. Among J&J vaccine recipients, the vaccine effectiveness against ICU admission or high care was 69% at 14 to 27 days and 82% at 1 to 2 months after the second dose; among the Pfizer recipients, effectiveness against ICU admission or high care was 70% at 1 to 2 months, 73% at 3 to 4 months, and 71% at > 5 months.

Gray et al concluded, “After two doses, both vaccines were equally effective against severe disease caused by the omicron variant. These estimates of vaccine effectiveness were calculated in a South African population with a high background prevalence of SARS-CoV-2 exposure during the Covid-19 pandemic. These data provide reassurance about the continued value of the national Covid-19 vaccine program during a surge in the omicron variant.”

Categories : COVIDTags :

Prior COVID Infection Results in Robust Immunity after Vaccination

On By ModernMedia
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New research published in the journal JCI Insight shows that immune responses to the Pfizer-BioNTech mRNA vaccine differ significantly in individuals depending on whether or not they had a prior COVID infection. Notably, those who had COVID before vaccination produced a surge of antibodies after the first dose, with little or no increase seen after the second dose. The opposite pattern was observed in infection-naïve individuals.

“Our study shows that the presence of immune memory induced by prior infection alters the way in which individuals respond to SARS-CoV-2 mRNA vaccination,” explained first author Professor Steven G. Kelsen. “The lack of response after the second vaccine dose in previously infected individuals is especially relevant, because it could mean that some people may require only one dose or could potentially skip the booster shot.”

Prof Kelsen and colleagues carried out the study in health care workers, some having previously tested positive for SARS-CoV-2 infection and others never having been infected. The researchers measured levels of neutralising antibodies in blood samples taken at three different time points, including before vaccination and after each vaccine dose. They also performed qualitative assessment for local reactions and systemic symptoms, such as fever, headache, and fatigue, associated with vaccination.

While levels of neutralising antibodies hit their maximum in some people with prior COVID after the first vaccine dose, individuals with no history of infection showed massive responses after the second dose. Those high levels also plummeted quickly, while the COVID group retained longer lasting immunity, despite the lack of response to a second dose. However, prior infection was also linked to more frequent and longer-lasting adverse reactions to the vaccine.

“Previous studies had similarly reported long-lasting immunity and strong immune reactions in COVID patients,” Prof Kelsen said. “We now provide new information on how prior infection interacts with vaccination in terms of measurable immune response and how individuals react to mRNA vaccines based on infection history.”

The next steps for Prof Kelsen and collaborators are to modify their neutralising antibody assay to detect Omicron and other SARS-CoV-2 variants. “We also are interested in understanding how long protection from a booster dose of the vaccine lasts,” he said.

Source: EurekAlert!

Categories : COVIDTags :

Three Doses are Needed for Same Protection against Omicron

On By ModernMedia
Syringe injection into the upper arm
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According to a large study published in The BMJ, mRNA vaccines are highly effective in preventing COVID hospital admissions related to the alpha, delta, and omicron variants. However, three doses are needed to achieve similar protection against omicron that two doses provide against delta and alpha.

The results also show that, although severity of disease among patients admitted to hospital is lower with the omicron versus delta variant, patients with omicron are still at risk of critical illness and death.

In order to guide vaccination policies and development of new vaccines, it is essential to understand COVID variants and vaccine efficacy.

Early studies suggested reduced vaccine effectiveness against infection and hospital admissions for omicron compared with earlier variants, but little is known about the effectiveness of vaccines to prevent the most severe manifestations of COVID, including respiratory failure and death, for patients with infection due to the omicron variant.

To address this, the researchers assessed COVID severity in the alpha, delta, and omicron variants among hospitalised adults and compared the effectiveness of two and three doses of mRNA vaccines (Pfizer-BioNTech and Moderna) in preventing hospital admissions related to each variant.

Their findings are based on 11 690 adults admitted to 21 hospitals across the United States between March 2021 and January 2022: 5728 cases with COVID and 5962 controls without COVID.

Patients were classified into alpha, delta or omicron based on viral gene sequencing or by the predominant circulating variant at the time of hospital admission.

Vaccine effectiveness was then calculated for each variant and variants’ disease severity was compared with the World Health Organization’s clinical progression scale.

Effectiveness of two doses of an mRNA vaccine to prevent COVID hospital admission was found to be lower for the omicron variant than alpha and delta variants (65%, 85%, and 85%, respectively), whereas three doses were found to achieve 86% effectiveness against the omicron variant, similar to two doses against the alpha and delta variants.

Among unvaccinated adults hospitalised with COVID, the delta variant was associated with the most severe disease, followed by the alpha variant and then the omicron variant.

The omicron variant was, however, associated with substantial critical illness and death, with 15% of patients admitted to hospital with the omicron variant (vaccinated and unvaccinated) progressing to invasive mechanical ventilation, and 7% dying in hospital.

Nevertheless, vaccinated patients hospitalised with COVID had significantly less sever disease than unvaccinated patients across all variants.

As an observational study, cause cannot be established, and some variant misclassification may have occurred. Changes in clinical management during the periods when the alpha, delta, and omicron variants predominated were not accounted for. These could have affected outcomes, the researchers acknowledged.

Nevertheless, this was a large study with rigorous evaluation of vaccination status and of outcomes beyond hospital admission, suggesting that the results are robust.

As such, they say that mRNA vaccines “were associated with strong protection against hospital admissions with COVID due to the alpha, delta, and omicron variants” and that vaccination against COVID including a third dose of an mRNA vaccine, “is critical for protecting populations against COVID-associated morbidity and mortality.”

They concluded: “As the COVID pandemic continues to evolve, routine monitoring of vaccine effectiveness, especially against severe disease, and surveillance programmes to identify viral variants will be essential to inform decisions about booster vaccine policies and vaccine strain updates.”

Source: EurekAlert!

Categories : COVID Immune SystemTags :

Existing COVID Vaccines Trigger Lasting T Cell Response

On By ModernMedia
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Scientists have found that four COVID vaccines (Pfizer-BioNTech, Moderna, J&J/Janssen, and Novavax) prompt the body to make effective, long-lasting T cells against SARS-CoV-2. These T cells can recognise SARS-CoV-2 Variants of Concern, including Delta and Omicron.

The new study, published in Cell, showed that the vast majority of T cell responses are also still effective against Omicron, reducing the odds of illness for up to six months, regardless of vaccine.

These data come from adults who were fully vaccinated, but not yet boosted. The researchers are now investigating T cell responses in boosted individuals and people who have experienced “breakthrough” COVID cases.

The study also shows that fully vaccinated people have fewer memory B cells and neutralising antibodies against the Omicron variant. This finding is in line with initial reports of waning immunity from laboratories around the world.

Without enough neutralising antibodies, Omicron is more likely to cause a breakthrough infection, and fewer memory B cells means a slower production of more neutralising antibodies.

Co-first author Camila Coelho, PhD, said: “Our study revealed that the 15 mutations present in Omicron RBD can considerably reduce the binding capacity of memory B cells.”

Neutralising antibodies and memory B cells are only two arms of the body’s adaptive immune response. , T cells do not prevent infection, rather they patrol the body and destroy cells that are already infected, which prevents a virus from multiplying and causing severe disease.

The team believes the “second line of defence” from T cells helps explain Omicron’s reduced severity in vaccinated people. The variant also appears to infect different tissues.

To know whether the vaccine-induced T cells they detected in their study were actually effective against variants such as Delta and Omicron, the scientists took a close look at how the T cells responded to different viral “epitopes.”

Every virus is made up of proteins that form a certain shape or architecture. A viral epitope is a specific landmark on this architecture that T cells have been trained to recognise. Current COVID vaccines were designed to teach the immune system to recognise specific epitopes on the initial variant of SARS-CoV-2, specifically targeting the Spike protein which the virus uses to access human cells. As the virus has mutated, its architecture has changed, and the concern is that immune cells will no longer recognise their targets.

The new study shows that while the architecture of Omicron is different enough to evade some neutralising antibodies and memory B cells, memory T cells still do a good job of recognising their targets, even on the highly mutated Omicron variant. Overall, at least 83 percent of the CD4+ (helper) T cell responses and 85 percent of the CD8+ T cell responses stayed the same, no matter the vaccine or the variant.

The memory B cells that do bind Omicron are likely to also contribute to protection against severe disease, forming multiple lines of defence. 

Researchers are now focusing on measuring T cells, B cells and antibody responses after COVID booster shots, and also characterising immune responses after a breakthrough infection.

Source: La Jolla Institute

Categories : COVIDTags :

Moderna Narrowly Beats Pfizer in Effectiveness

On By ModernMedia
Image of a syringe for vaccination
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In the first head-to-head comparison of the effectiveness of the Pfizer-BioNTech and Moderna COVID vaccines, researchers examined the electronic health records of veterans who had received each vaccine and found Moderna to be slightly more effective.

The Moderna vaccine’s increased level of protection included a 21% lower risk of documented infection and 41% lower risk of hospitalisation, according to the research team, whose findings were published in the New England Journal of Medicine.

“Both vaccines are incredibly effective, with only rare breakthrough cases,” said Dr J.P. Casas, a member of the research team. “But regardless of the predominant strain – Alpha earlier and then Delta later – Moderna was shown to be slightly more effective.”

Researchers designed their comparative effectiveness study to address the previously unanswered question of which of the two mRNA vaccines is more effective. Effectiveness outcomes were: documented COVID, symptomatic disease, hospitalisation, ICU admission, and death. The investigators drew on the database of US veterans who received one of the two COVID vaccines between early January 2021 and mid-May 2021.

As initially designed, the research focused on the Alpha variant that predominated at the time. The study matched 219 842 recipients of the Pfizer vaccine to the same number of recipients of the Moderna vaccine. The two groups were matched based on a variety of clinical and demographic factors that could affect outcomes.

Over the study’s 24-week follow-up period, the estimated risk of documented infection was 4.52 events per 1000 people in the Moderna vaccine group and 5.75 per 1000 in the Pfizer group, an excess of 1.23 cases per 1000. The investigators also observed smaller excesses of symptomatic COVID (0.44 events), hospitalisation (0.55 events), ICU admission (0.10 events), and death (0.02 events) per 1000 people in the Pfizer group relative to the Moderna group.

This pattern of a lower risk for Moderna held up when Delta was the main strain. In this comparison, excess risk of documented infection over 12 weeks was 6.54 events per 1000 people for the Pfizer vaccine, compared to Moderna. Given the shorter time frame available for this supplementary research, infection was the only outcome researchers analyzed. Also, the estimates were considered less precise because a smaller number of individuals were eligible for this analysis.

Randomised trials comparing the mRNA vaccines against placebos had previously shown both vaccines to be very effective against symptomatic COVID infection (95% effectiveness for Pfizer-BioNTech, 94% for Moderna), borne out by real-world vaccine use.

“Given the high effectiveness of both the Moderna and Pfizer vaccines, confirmed by our study, either one is recommended to any individual offered a choice between the two,” said first author Dr Barbra A. Dickerman. “However, while the estimated differences in effectiveness were small on an absolute scale, they may be meaningful when considering the large population scale at which these vaccines are deployed. This information may be helpful for larger decision-making bodies.”

The massive Veteran Association records system supported a very large sample size. This, in turn, allowed the study to identify even small differences in effectiveness between the Pfizer and Moderna vaccines. The researchers used a methodology known as causal inference to mirror a gold standard randomised trial as closely as possible. Causal inference is a type of data analysis that helps researchers draw firm conclusions about cause and effect.

Using the VA database, vaccine recipients were closely matched on age, sex, race, geographic location, and other attributes that could affect COVID-related outcomes.

“After this careful matching, we found that the two vaccine groups were extremely similar in terms of variables with respect to an extensive set of demographic, geographic, and health-related attributes,” Dr Dickerman said. “This allowed our observational analysis to produce exceptionally credible results during a global emergency, when answers are needed fast and randomised trials can be impractical.”

As the global pandemic continues to unfold, the research team is working on answers relating to the comparative safety, versus effectiveness, of the Pfizer and Moderna vaccines. Dr Dickerman characterises comparative safety as an “additional piece of the puzzle to support vaccine decision-making.”

Even beyond this analysis, further evaluation of the vaccines’ comparative effectiveness and safety is needed, the authors concluded. Meanwhile, given the evidence at hand, the authors concluded about the Pfizer and Moderna vaccines considered in their study, “Given the high effectiveness and safety profile of both mRNA vaccines, either one is strongly recommended.”

Source: EurekAlert!