Researcher blows the whistle on data integrity issues in Pfizer’s vaccine trial

BMJ 2021; 375 doi: https://doi.org/10.1136/bmj.n2635 (Published 02 November 2021) Cite this as: BMJ 2021;375:n2635
  1. Paul D Thacker, investigative journalist

Author affiliations

Revelations of poor practices at a contract research company helping to carry out Pfizer’s pivotal covid-19 vaccine trial raise questions about data integrity and regulatory oversight. Paul D Thacker reports

In autumn 2020 Pfizer’s chairman and chief executive, Albert Bourla, released an open letter to the billions of people around the world who were investing their hopes in a safe and effective covid-19 vaccine to end the pandemic. “As I’ve said before, we are operating at the speed of science,” Bourla wrote, explaining to the public when they could expect a Pfizer vaccine to be authorised in the United States.1

But, for researchers who were testing Pfizer’s vaccine at several sites in Texas during that autumn, speed may have come at the cost of data integrity and patient safety. A regional director who was employed at the research organisation Ventavia Research Group has told The BMJ that the company falsified data, unblinded patients, employed inadequately trained vaccinators, and was slow to follow up on adverse events reported in Pfizer’s pivotal phase III trial. Staff who conducted quality control checks were overwhelmed by the volume of problems they were finding. After repeatedly notifying Ventavia of these problems, the regional director, Brook Jackson, emailed a complaint to the US Food and Drug Administration (FDA). Ventavia fired her later the same day. Jackson has provided The BMJ with dozens of internal company documents, photos, audio recordings, and emails.

Poor laboratory management

On its website Ventavia calls itself the largest privately owned clinical research company in Texas and lists many awards it has won for its contract work.2 But Jackson has told The BMJ that, during the two weeks she was employed at Ventavia in September 2020, she repeatedly informed her superiors of poor laboratory management, patient safety concerns, and data integrity issues. Jackson was a trained clinical trial auditor who previously held a director of operations position and came to Ventavia with more than 15 years’ experience in clinical research coordination and management. Exasperated that Ventavia was not dealing with the problems, Jackson documented several matters late one night, taking photos on her mobile phone. One photo, provided to The BMJ, showed needles discarded in a plastic biohazard bag instead of a sharps container box. Another showed vaccine packaging materials with trial participants’ identification numbers written on them left out in the open, potentially unblinding participants. Ventavia executives later questioned Jackson for taking the photos.

Early and inadvertent unblinding may have occurred on a far wider scale. According to the trial’s design, unblinded staff were responsible for preparing and administering the study drug (Pfizer’s vaccine or a placebo). This was to be done to preserve the blinding of trial participants and all other site staff, including the principal investigator. However, at Ventavia, Jackson told The BMJ that drug assignment confirmation printouts were being left in participants’ charts, accessible to blinded personnel. As a corrective action taken in September, two months into trial recruitment and with around 1000 participants already enrolled, quality assurance checklists were updated with instructions for staff to remove drug assignments from charts.

In a recording of a meeting in late September2020 between Jackson and two directors a Ventavia executive can be heard explaining that the company wasn’t able to quantify the types and number of errors they were finding when examining the trial paperwork for quality control. “In my mind, it’s something new every day,” a Ventavia executive says. “We know that it’s significant.”

Ventavia was not keeping up with data entry queries, shows an email sent by ICON, the contract research organisation with which Pfizer partnered on the trial. ICON reminded Ventavia in a September 2020 email: “The expectation for this study is that all queries are addressed within 24hrs.” ICON then highlighted over 100 outstanding queries older than three days in yellow. Examples included two individuals for which “Subject has reported with Severe symptoms/reactions … Per protocol, subjects experiencing Grade 3 local reactions should be contacted. Please confirm if an UNPLANNED CONTACT was made and update the corresponding form as appropriate.” According to the trial protocol a telephone contact should have occurred “to ascertain further details and determine whether a site visit is clinically indicated.”

Worries over FDA inspection

Documents show that problems had been going on for weeks. In a list of “action items” circulated among Ventavia leaders in early August 2020, shortly after the trial began and before Jackson’s hiring, a Ventavia executive identified three site staff members with whom to “Go over e-diary issue/falsifying data, etc.” One of them was “verbally counseled for changing data and not noting late entry,” a note indicates.

At several points during the late September meeting Jackson and the Ventavia executives discussed the possibility of the FDA showing up for an inspection (box 1). “We’re going to get some kind of letter of information at least, when the FDA gets here . . . know it,” an executive stated.

Box 1

A history of lax oversight

When it comes to the FDA and clinical trials, Elizabeth Woeckner, president of Citizens for Responsible Care and Research Incorporated (CIRCARE),3 says the agency’s oversight capacity is severely under-resourced. If the FDA receives a complaint about a clinical trial, she says the agency rarely has the staff available to show up and inspect. And sometimes oversight occurs too late.

In one example CIRCARE and the US consumer advocacy organisation Public Citizen, along with dozens of public health experts, filed a detailed complaint in July 2018 with the FDA about a clinical trial that failed to comply with regulations for the protection of human participants.4 Nine months later, in April 2019, an FDA investigator inspected the clinical site. In May this year the FDA sent the triallist a warning letter that substantiated many of the claims in the complaints. It said, “[I]t appears that you did not adhere to the applicable statutory requirements and FDA regulations governing the conduct of clinical investigations and the protection of human subjects.”5

“There’s just a complete lack of oversight of contract research organisations and independent clinical research facilities,” says Jill Fisher, professor of social medicine at the University of North Carolina School of Medicine and author of Medical Research for Hire: The Political Economy of Pharmaceutical Clinical Trials.

Ventavia and the FDA

A former Ventavia employee told The BMJ that the company was nervous and expecting a federal audit of its Pfizer vaccine trial.

“People working in clinical research are terrified of FDA audits,” Jill Fisher told The BMJ, but added that the agency rarely does anything other than inspect paperwork, usually months after a trial has ended. “I don’t know why they’re so afraid of them,” she said. But she said she was surprised that the agency failed to inspect Ventavia after an employee had filed a complaint. “You would think if there’s a specific and credible complaint that they would have to investigate that,” Fisher said.

In 2007 the Department of Health and Human Services’ Office of the Inspector General released a report on FDA’s oversight of clinical trials conducted between 2000 and 2005. The report found that the FDA inspected only 1% of clinical trial sites.6 Inspections carried out by the FDA’s vaccines and biologics branch have been decreasing in recent years, with just 50 conducted in the 2020 fiscal year.7

RETURN TO TEXT

The next morning, 25 September 2020, Jackson called the FDA to warn about unsound practices in Pfizer’s clinical trial at Ventavia. She then reported her concerns in an email to the agency. In the afternoon Ventavia fired Jackson—deemed “not a good fit,” according to her separation letter.

Jackson told The BMJ it was the first time she had been fired in her 20 year career in research.

Concerns raised

In her 25 September email to the FDA Jackson wrote that Ventavia had enrolled more than 1000 participants at three sites. The full trial (registered under NCT04368728) enrolled around 44 000 participants across 153 sites that included numerous commercial companies and academic centres. She then listed a dozen concerns she had witnessed, including:

  • Participants placed in a hallway after injection and not being monitored by clinical staff

  • Lack of timely follow-up of patients who experienced adverse events

  • Protocol deviations not being reported

  • Vaccines not being stored at proper temperatures

  • Mislabelled laboratory specimens, and

  • Targeting of Ventavia staff for reporting these types of problems.

Within hours Jackson received an email from the FDA thanking her for her concerns and notifying her that the FDA could not comment on any investigation that might result. A few days later Jackson received a call from an FDA inspector to discuss her report but was told that no further information could be provided. She heard nothing further in relation to her report.

In Pfizer’s briefing document submitted to an FDA advisory committee meeting held on 10 December 2020 to discuss Pfizer’s application for emergency use authorisation of its covid-19 vaccine, the company made no mention of problems at the Ventavia site. The next day the FDA issued the authorisation of the vaccine.8

In August this year, after the full approval of Pfizer’s vaccine, the FDA published a summary of its inspections of the company’s pivotal trial. Nine of the trial’s 153 sites were inspected. Ventavia’s sites were not listed among the nine, and no inspections of sites where adults were recruited took place in the eight months after the December 2020 emergency authorisation. The FDA’s inspection officer noted: “The data integrity and verification portion of the BIMO [bioresearch monitoring] inspections were limited because the study was ongoing, and the data required for verification and comparison were not yet available to the IND [investigational new drug].”

Other employees’ accounts

In recent months Jackson has reconnected with several former Ventavia employees who all left or were fired from the company. One of them was one of the officials who had taken part in the late September meeting. In a text message sent in June the former official apologised, saying that “everything that you complained about was spot on.”

Two former Ventavia employees spoke to The BMJ anonymously for fear of reprisal and loss of job prospects in the tightly knit research community. Both confirmed broad aspects of Jackson’s complaint. One said that she had worked on over four dozen clinical trials in her career, including many large trials, but had never experienced such a “helter skelter” work environment as with Ventavia on Pfizer’s trial.

“I’ve never had to do what they were asking me to do, ever,” she told The BMJ. “It just seemed like something a little different from normal—the things that were allowed and expected.”

She added that during her time at Ventavia the company expected a federal audit but that this never came.

After Jackson left the company problems persisted at Ventavia, this employee said. In several cases Ventavia lacked enough employees to swab all trial participants who reported covid-like symptoms, to test for infection. Laboratory confirmed symptomatic covid-19 was the trial’s primary endpoint, the employee noted. (An FDA review memorandum released in August this year states that across the full trial swabs were not taken from 477 people with suspected cases of symptomatic covid-19.)

“I don’t think it was good clean data,” the employee said of the data Ventavia generated for the Pfizer trial. “It’s a crazy mess.”

A second employee also described an environment at Ventavia unlike any she had experienced in her 20 years doing research. She told The BMJ that, shortly after Ventavia fired Jackson, Pfizer was notified of problems at Ventavia with the vaccine trial and that an audit took place.

Since Jackson reported problems with Ventavia to the FDA in September 2020, Pfizer has hired Ventavia as a research subcontractor on four other vaccine clinical trials (covid-19 vaccine in children and young adults, pregnant women, and a booster dose, as well an RSV vaccine trial; NCT04816643, NCT04754594, NCT04955626, NCT05035212). The advisory committee for the Centers for Disease Control and Prevention is set to discuss the covid-19 paediatric vaccine trial on 2 November.

Footnotes

  • Provenance and peer review: commissioned; externally peer reviewed.

  • Competing interests: PDT has been doubly vaccinated with Pfizer’s vaccine.

This article is made freely available for use in accordance with BMJ’s website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose (including text and data mining) provided that all copyright notices and trade marks are retained.

https://bmj.com/coronavirus/usage

References

 

View Abstract

Bridle busts open nonsensical vaccine attitudes and rules

A passionate and dispassionate dissection of Covid ‘vaccines’, and ridiculous mandates and use of them by authorities, from Byram Bridle, Associate Professor of Viral Immunology, at the
University of Guelph.

2021-09-17 – Open letter to the president of the U of G_B.Bridle

Sweden excess mortality lower than most of Europe

In contrast to the harsh, repeated, extended lockdowns of nations such as the UK, Sweden let citizens work out their own approach to Covid19.

The result was a much smaller spike in deaths above normal in 2020 than most of Europe – 0.03%.

https://www.reuters.com/article/us-health-coronavirus-europe-mortality-idUSKBN2BG1R9 

Why we spoke out

Martin Kulldorff explains the rationale of the covid skeptics who feel compelled to speak out.

It has been hard to find any prominent NZer prepared to resist the covid fear-mongering and the Covid elimination strategy. Fortunately, those so vehemently in favour of fear and ‘zero covid’ plans have recorded their opinions for when the future comes looking to find blame.

https://www.spiked-online.com/2021/06/04/why-i-spoke-out-against-lockdowns/

I had no choice but to speak out against lockdowns. As a public-health scientist with decades of experience working on infectious-disease outbreaks, I couldn’t stay silent. Not when basic principles of public health are thrown out of the window. Not when the working class is thrown under the bus. Not when lockdown opponents were thrown to the wolves. There was never a scientific consensus for lockdowns. That balloon had to be popped.

 

Instead of understanding the pandemic, we were encouraged to fear it. Instead of life, we got lockdowns and death. We got delayed cancer diagnoses, worse cardiovascular-disease outcomes, deteriorating mental health, and a lot more collateral public-health damage from lockdown. Children, the elderly and the working class were the hardest hit by what can only be described as the biggest public-health fiasco in history.

No mortality difference between Sweden and Norway, but Norway result came at huge cost

An important study (preprint at time of this post) shows similar mortality rates in Sweden and Norway despite different national responses to the Covid19 virus. But critically, Sweden’s mortality outcome came at a much cheaper economic cost.
Despite an order of magnitude difference in case-fatality rates in Sweden (higher) compared to Norway, the two countries had very similar overall mortality profiles.
There was a big difference though in national costs. Norway’s more restrictive policies resulting in public spending 2.6-fold more than Sweden (Norway: 4,176 Euros per person & Sweden 1,580 per person) during the epidemic.
It also reveals that the spike in mortality in Sweden which had caused consternation, and some unfortunate glee among pro-lockdown observers, was most likely due to ‘displaced mortality’ from low mortality in earlier seasons. Norway had no overall mortality spike.

Lead vaccines: answers needed

As lead vaccines announce good results and intentions to register for fast-tracked safety authorisation in EU and the US, immunologist Byram Bridle, reminds us of questions that they will need to answer:

Dr. Byram Bridle, PhD, Associate Professor of Viral Immunology, University of Guelph, Ontario, Canada

  1. How many of the total study subjects are being reported on? Partial results can range from being representative of the entire data set to being biased.
  2. How many study subjects had detectable immune responses and what was the magnitude?
  3. Were there antibody responses in the respiratory tract, which is where SARS-CoV-2 infects, and did these antibodies efficiently neutralize the virus?
  4. Were SARS-CoV-2-specific T cells induced? A balanced anti-viral response should include antibodies to prevent infection and T cells to kill viruses that get past the antibody barrier.
  5. Did the immune responses have a ‘Th1’ or ‘Th2’ bias? The former type of immune response is optimal against viruses, the latter is usually sub-optimal and sometimes even dangerous in the context of respiratory viral infections.
  6. Did the vaccine confer long-term immunological memory? A prophylactic vaccine may be useless without this. If immunological memory is short-lived, vaccinated individuals could become susceptible to infection before enough people are immunized to achieve ‘herd immunity’. Another term for this is ‘duration of immunity’ (i.e. how long does immunological protection last?)
  7. How did the vaccine perform in senescent animals and/or elderly humans? Those most in need of protection against COVID-19 are the elderly and immunocompromised.
  8. How was safety assessed and what were the results?
  9. Have the results been published for review by other scientists? If not, when? It is recommended to publish in open-access journals, which are available to the public. Comments merely reflect opinions unless there are validated data to back them up.
  10. Related to #6 above, what is the plan to manufacture and roll-out enough vaccine doses to achieve herd immunity in any given country? What is the realistic timeline for this? If >1 year, there is no way to know if COVID-19 vaccines will confer protection for this long because they didn’t exist one year ago. The development of every historical vaccine took >4 years, so there were years-worth of ‘duration of immunity’ data. For example, optimistic projections suggest ~1 billion doses might be possible by the end of 2021, but for two-dose regimens, that means only 500 million people could potentially be vaccinated in just over one year. With the global population at 7.8 billion people, that represents only 6% of the world’s population. The lowest estimate to achieve herd immunity is 60%.
  11. How will equitable distribution of vaccines be accomplished? For example, pre-order waiting lists seem to be dominated by developed countries; are any developing countries on these waiting lists?
  12. What is the cost of a full vaccine regimen going to be? Is it affordable for developing countries? Some epidemiologists have predicted that efficient roll-out of vaccines to developing countries will require the price to be <$6 US.
  13. Storage conditions for vaccines could impact distribution and market competitiveness. What data are available to support the claimed storage conditions? For example, the default storage temperature for RNA in research laboratories is -80o This is based on a plethora of scientific evidence that RNA is more stable at this temperature compared to -20oC.

An uncompromising expression of the Covid-skeptic position

Even our jaws dropped at this compelling, powerful, uncompromising statement from a Canadian doctor to the Edmonton City Council Community and Public Services Committe.

Hodkinson is the CEO of Western Medical Assessments, and has been the company’s medical director for over 20 years. He received his general medical degrees from Cambridge University in the U.K., and then became a Royal College certified pathologist in Canada (FRCPC) following a residency in Vancouver.

He also taught at the University of Alberta and runs MutantDx, a molecular diagnostics company in North Carolina.

Dr Hodkinson – Canada

That time when no one noticed Covid19

A study shows a ‘peak’ of Covid19 cases in Italy in September 2019, and no one had noticed.

This hints that Covid19 was circulating even earlier, as the study used blood samples from a lung cancer patient screening trial that had begun in September 2019.

This study shows an unexpected very early circulation of SARS-CoV-2 among asymptomatic individuals in Italy several months before the first patient was identified, and clarifies the onset and spread of the coronavirus disease 2019 (COVID-19) pandemic. Finding SARS-CoV-2 antibodies in asymptomatic people before the COVID-19 outbreak in Italy may reshape the history of pandemic.

https://journals.sagepub.com/doi/10.1177/0300891620974755

Immunologist cautions on lead vaccines

17 November 2020

Byram Bridle, a viral immunologist at the University of Guelph, cautions New Zealanders that the lead vaccines against Covid19 may not be the solution they are expecting to end its isolation under the elimination strategy.

The main points of his caution are:

  1. NZ will have to wait at least two years before the Pfizer vaccine is available, because it is in strict isolation and low on the priority list for the 500m doses available in 2021.
  2. Not enough data has been released to know whether the vaccine prevents or weakens the symptoms of Covid19, or how long the protection will last.
  3. The safety data will be incomplete if it is approved for use next year, so monitoring will need to be carried out on vaccinated people for some years.
  4. The Pfizer data has not been rigorously peer-reviewed.
  5. There is no available data on the qualitative nature of the immune response. Vaccines like this can be misinterpreted by the immune system as an extracellular pathogen, which can cause them to respond poorly to natural infections with future coronaviruses.

“Pfizer’s vaccine is a RNA-vectored vaccine. This technology is relatively new and has not been approved for clinical use before. The company has been able to move surprisingly fast. If the recent data is indicative of what data from the rest of the trial will look like, there is a good chance the vaccine could receive emergency approval by early in 2021.

However, there are many nuances…”

Insufficient public data

“The study is only partially complete. There exists the possibility that the final data set will fail to secure regulatory approval (but it looks like they may be on track).

Data that accompanied the Pfizer press release was extremely superficial and, therefore, difficult to interpret. Data being collected for the Pfizer study cannot accurately be commented on until it undergoes rigorous peer review for publication in a good quality scientific journal.”

Effectiveness of protection

“90% effectiveness sounds surprisingly high. But we have no idea what the demographics look like. Although they opened the trial to high-risk people, we have no idea who contracted COVID-19. As an extreme example, if all the vaccinated volunteers that got COVID-19 were elderly and that number was not significantly different from the elderly among the non-vaccinated volunteers that got COVID-19, that would tell us that the vaccine does not work in those who need it most.

Most of the cases of COVID-19 in the study were presumably mild to moderate since no hospitalizations or deaths were reported, so we don’t know how protective the vaccine will be for those who are susceptible to severe cases.

There is no data regarding immunological memory, which is the entire point of a vaccine. If the memory response is weak or wanes too quickly, people will not be protected over the long term. This would be a fatal flaw because the global roll-out of a vaccine will take a very long time.

Pfizer hasn’t stated what the qualitative nature of the vaccine-induced immune response is. Sub-unit vaccines like theirs have been known to be misinterpreted by the immune system as being an extracellular pathogen. If that is the case, people who receive this vaccine might have a bias imprinted on their immune system that could cause them to respond to natural infections with future coronaviruses in a sub-par fashion.”

Two dose vaccine.

  • “It can be hard to get people back for a second dose. It is probably achievable in urban centres but could be hard to get the same people back 21 days later in remote and/or difficult-to-access places, especially in developing countries.
  • A vaccine that needs two doses is arguably a ‘weak’ vaccine. For this vaccine, it will take 28 days to build up sufficient protection. So there will be a one-month window during which people will remain susceptible. A better quality, single-dose vaccine could probably reduce this to 10-14 days.
  • Fewer than 500 million people could be vaccinated within a year of the vaccine being approved. The company is going to try to stockpile 50 million vaccines this year in anticipation of the vaccine being approved, and they optimistically predict that they can make 1.3 billion doses by the end of 2021. This sounds like a lot, but a two-dose regimen cuts the number of people that can be immunized in half. The person to get the 500 millionth dose will have to wait a year compared to the person who gets the first one. Some will wonder why some people get two doses while they get none. The vaccine won’t be protective unless two doses are given.”

Roll out internationally

“What about the rest of the population? As many of us have been predicting, it could take years to roll out these vaccines. Approval of a vaccine doesn’t help anyone; what matters is when it has been administered and sufficient time has passed for the immune system to respond. Of course, where in this very long timeline for the roll-out will countries that have used strict isolation to control their cases be (arguably, low on the priority list). Pfizer’s press release is essentially saying that everyone beyond the first half-million people will have to wait over 1 year. Presumably, it also means that people beyond the first billion or so may have to wait over 2 years.”

Long term safety

“Long-term safety in people is inferred based on animal models (such as rodents) that have shorter lifespans. Usually, clinical trials are done sequentially and span quite a few years. So acute and some long-term (i.e. 4 or more years) safety data would be in-hand. With the different trial stages overlapping and being run faster than normal, we will likely have less than a year’s-worth of safety data. Ultimately, the only way to be completely sure about long-term (i.e. beyond the duration of the clinical trial phase) safety in people is to monitor vaccinated people for a long period of time after the roll-out. Things like long-term kidney damage, etc. can often (but not always) be predicted/ruled out by things like blood chemistry within the acute stages.”

/ends

No appreciable risk of Covid19 infection from close contact with children

Another piece of evidence against lockdowns; research shows close contact with children under 11 has no increased risk of Covid19 infection, close contact with those 12-18 has a small increased risk of infection, while there was no impact on outcomes of being infected with Covid19. As a bonus, closeness to children reduces non-Covid19 deaths….

Working on behalf of NHS England, we conducted a population-based cohort study using primary care data and pseudonymously-linked hospital and intensive care admissions, and death records, from patients registered in general practices representing 40% of England. Using multivariable Cox regression, we calculated fully-adjusted hazard ratios (HR) of outcomes from 1st February-3rd August 2020 comparing adults living with and without children in the household.

Findings Among 9,157,814 adults ≤65 years, living with children 0-11 years was not associated with increased risks of recorded SARS-CoV-2 infection, COVID-19 related hospital or ICU admission but was associated with reduced risk of COVID-19 death (HR 0.75, 95%CI 0.62-0.92). Living with children aged 12-18 years was associated with a small increased risk of recorded SARS-CoV-2 infection (HR 1.08, 95%CI 1.03-1.13), but not associated with other COVID-19 outcomes. Living with children of any age was also associated with lower risk of dying from non-COVID-19 causes. Among 2,567,671 adults >65 years there was no association between living with children and outcomes related to SARS-CoV-2. We observed no consistent changes in risk following school closure.

Interpretation For adults living with children there is no evidence of an increased risk of severe COVID-19 outcomes. These findings have implications for determining the benefit-harm balance of children attending school in the COVID-19 pandemic.

Funding This work was supported by the Medical Research Council MR/V015737/1.

Evidence before this study We searched MEDLINE on 19th October 2020 for population-based epidemiological studies comparing the risk of SARS-CoV-2 infection and COVID-19 disease in people living with and without children. We searched for articles published in 2020, with abstracts available, and terms “(children or parents or dependants) AND (COVID or SARS-CoV-2 or coronavirus) AND (rate or hazard or odds or risk), in the title, abstract or keywords. 244 papers were identified for screening but none were relevant. One additional study in preprint was identified on medRxiv and found a reduced risk of hospitalisation for COVID-19 and a positive SARS-CoV-2 infection among adult healthcare workers living with children.

Added value of this study This is the first population-based study to investigate whether the risk of recorded SARS-CoV-2 infection and severe outcomes from COVID-19 differ between adults living in households with and without school-aged children during the UK pandemic. Our findings show that for adults living with children there is no evidence of an increased risk of severe COVID-19 outcomes although there may be a slightly increased risk of recorded SARS-CoV-2 infection for working-age adults living with children aged 12 to 18 years. Working-age adults living with children 0 to 11 years have a lower risk of death from COVID-19 compared to adults living without children, with the effect size being comparable to their lower risk of death from any cause. We observed no consistent changes in risk of recorded SARS-CoV-2 infection and severe outcomes from COVID-19 comparing periods before and after school closure.

Implications of all the available evidence Our results demonstrate no evidence of serious harms from COVID-19 to adults in close contact with children, compared to those living in households without children. This has implications for determining the benefit-harm balance of children attending school in the COVID-19 pandemic.

 

 

https://www.medrxiv.org/content/10.1101/2020.11.01.20222315v1