Covid-19 likely to be man made

lucernarian wrote: »

That's not to do with where discussion on contemporary scientific issues takes place, and I don't think you're a mod who moves threads like these.

Sure. But it's the reason why the topic was dumped here.
Maybe you could start a thread in a more appropriate forum were the wild nonsense theories aren't welcome along side the legitimate concerns.

that ended this thread

Deleted User wrote: »

So both of you have been on this forum for years trying to 'debunk' all conspiracy theories? You both talk alike, both believe the same thing (ie no conspiracy theories), yet still spend a lot of time on the conspiracy theories forums. So, so strange..

We've questioned before the reasons why one person would bother doing this, let alone two.

I'm start to think you're both the same person. It's the only thing that would make sense :pac:

There's no debunkers on boards.ie any more. They're all on journal.ie now - see the "debunked" features there which invariably tell us half tested mRNA vaccines are good for us regardless of adverse effect reports and a virus that has a 99% survival rate is going to kill us.

King Mob wrote: »

But the vaccines have been tested.

Yes, the vaccines or "jabs" have been tested but not over a long period of time. I'm calling it the covid mRNA jab because it works in a different way to what we have known up until now as vaccines. Many people would be happier if the covid mRNA jab had been put through longitudinal tests of 5 years or even a generation to study long-term adverse effects. The people getting the covid mRNA jab now are part of a 2 year longitudinal test but not all of them know that. Some of the covid jabs are the first mRNA treatments to be widely available. The covid mRNA jab works in a different way to vaccines such as the flu vaccine. It's better to test any drug including vaccines or mRNA jabs over a long period of time rather than release it early and have to withdraw it due to unpleasant and sometimes tragic side-effects.

King Mob wrote: »

What adverse effects are you refering to,

Death
Convulsions
Miscarriage
Fever and Bells Palsy(not the worst ones, people often recover from that)

King Mob wrote: »

where did you get this information and how did you verify it?

Anecdotal evidence. It's hard to ask dead people to verify what killed them.

King Mob wrote: »

What's the rate of incidence of this negative effects?

I can't tell you that because people are still getting the covid mRNA jab and many are suffering side effects which are being reported.

King Mob wrote: »

And again, covid has killed over 2 million people.

Is that people who died OF covid or WITH covid?

King Mob wrote: »

So why did you lie and say that it wasn't tested?

It was tested.
mRNA vaccines have been in development for over a decade.

I did not lie. Please do not make false accusations. I said that the covid mRNA jab had not been tested longitudinally. It was intensively tested over a short period of time and pushed on to the market to be tested in the community for 2 years without people knowing. Read the small print in the Comirnaty jab literature and follow the links for more information.

I know that mRNA jabs have been in development for over a decade. Were they tested in the community during this time as well as in the lab?

If so what was the outcome of the tests in the lab? Was it successful? If so what was the rate of success?

What was the outcome of the tests in the wild or in the community? Was it successful? If so what was the rate of success?

Viruses mutate so if tests were successful in the lab and in the community does this mean the mRNA jab works with mutated versions or will people have to top up their jabs every month?

Is the success rate of the covid mRNA jab superior to the recovery rate of the general population to covid? If not why are people being given an mRNA jab which in my opinion needs more testing.

King Mob wrote: »

Sorry, you've dodged most of my questions.

Provide your source for your claims of adverse effects please.

If you can't provide a legitimate source, please don't just dodge and evade. Admit that you can't.

Please read my last post again and you will see that I have not dodged your questions. However you have dodged mine.

King Mob wrote: »

Ok. You've no source for you claims of adverse effects.
You lied. Cool.

Why are you claiming this then?

False accusations again. I did not lie.

First of all, up until this point there has never been a successful vaccine for coronaviruses in humans due to a problem typical of coronavirus vaccine development called antibody dependent enhancement or ADE. [1] In preliminary animal trials for previous coronavirus vaccines (SARS and MERS), animals were vaccinated and seemed to exhibit a robust antibody response, but upon exposure to the wild virus, they developed a paradoxical immune enhancement leading to severe organ inflammation (especially in lungs), and they died. [2][3] Paradoxical immune response in coronavirus vaccines has also taken place in human trials, which occurred during testing of the failed RSV vaccines of the 1950s. [4] Alarmingly, there are some statistical indications of ADE in covid vaccine trials, but there is no way to know for sure because many key signifiers of ADE weren’t specifically addressed. [5] Due to emergency protocol, the usual method of testing animals prior to humans was bypassed, limited animal testing occurred in parallel with humans, and the potential for ADE was not comprehensively assessed. [6] [7] [54] Historical precedent would suggest, however, that ADE is a distinct possibility, and we may not know the true negative effects until years from now when vaccinated persons are exposed to SARS-CoV-2 or genetically similar versions of coronavirus. [8]

Second, the Pfizer and Moderna vaccines contain lipid nanoparticles that are “PEGylated”, meaning the nanoparticles are coated with PEG (polyethylene glycol).[9] PEGs can lead to life threatening anaphylaxis or other conditions such as thrombocytopenia. [10][50] Such reactions are already occurring during the initial vaccine rollout and PEGs are the most likely culprit. [11] Approximately 72% of the US population have PEG antibodies, with 8% having extremely elevated levels (more than 500 ng/mL), putting them at risk for severe allergic reaction and/or future autoimmune disorders. [12] These reactions were totally predictable, with many experts warning of the danger posed by PEGs [13][14][15][55], yet participants with a history of severe allergic reaction were excluded from the trials, serving to obscure the actual negative impact PEGs will have now that these vaccines are being given to members of the public who have not been screened for PEG antibodies. [16][53] Also, there is some worrying evidence to suggest that PEGs cross the blood-brain barrier and accumulate in the brain, possibly causing inflammation and/or autoimmune conditions, a fact gleaned from previous animal studies on mRNA vaccines. PEGs were found to be distributed across a spectrum of tissues including the brain. [52] Additionally, nanoparticles (such as PEGylated hydrogel) are known components for state of the art medical interventions, including biosurveillance technology currently being developed by DARPA and companies like Profusa Inc. [17][18][19][20][21] The secretive nature of this technology necessitates a knowledge gap between developers and the general public, so although my research efforts have yet to verify a direct functional relationship between PEGylated nanoparticles used in covid vaccines and biosurveillance, I personally do not relish the prospect of being injected with such given their association with biosurveillance technology of the military industrial complex.

Third, it is impossible to ascertain long term safety because of the foreshortened timeframe of Operation Warp Speed. [22] Vaccines should be tested for multiple years to adequately assess their longterm effects. [23] Short term safety is questionable too, as much of the data is still unavailable, and the current reports on safety and efficacy essentially amount to self-reported press releases from these companies themselves. [24]

Fourth, the efficacy number of 90% for Pfizer and 94% for Moderna is statistically misleading, reporting a relative reduction instead of absolute reduction of risk*. Also, the trials only assessed these vaccines’ ability to prevent mild symptoms and NOT their ability to prevent transmission. [25] If they don’t prevent people from transmitting the virus (especially when safer, cheaper drugs like Ivermectin do) [26][27] what’s the point?

Fifth, these are NOT vaccines in the normal sense. They are mRNA vaccines, which utilize a completely different process for achieving disease protection**; mRNA vaccines seek to introduce messenger RNA into the body in order to “trick” cells into producing immunogens, which then stimulate an immune response. [28] These vaccines are the first of their kind ever to gain authorization. [29] Current vaccinations are essentially an extension of phase 3 of the trials. [30] Because of the lack of long term safety assessment and the new nature of this technology, people are participating in a mass human experiment with no way of knowing the long term health effects these could cause. Many problems from vaccines are known to have an incubatory period and do not manifest until much later, which is why testing needs to occur for multiple years in order to adequately assess risk. [31] One such problem currently being discussed is the mRNA technology’s possible impact on female fertility, as it encourages the production of antibodies against a SARS-CoV-2 spike protein that contains a very similar protein crucial for the development of placenta called syncytin-1. This could interfere with the reproductive process by encouraging the immune system to react against syncytin-1, thereby disrupting placental development. [32] The vaccines’ impact on fertility is currently unknown as animal reproductive toxicity studies have not been completed. [33]

Sixth, there was a signature for many different problems seen in the various trials and initial rollout for these vaccines, problems that are concurrent with commonly documented vaccine injuries. Injuries that did occur in the various trials/rollout have included, but are not limited to, anaphylaxis, Bell’s palsy, transverse myelitis, multi-system inflammatory syndrome, dyskinesia, myalgic encephalomyelitis, idiopathic thrombocytopenia purpura, and death. [34][35][36][37][50][51][56]

Seventh, and perhaps most importantly, the movement toward potential vaccine mandates or other coercive policies violates humanity’s most universally accepted principles of human rights and medical ethics, especially for a medical intervention with so many known and unknown safety/efficacy concerns. The absolute bedrock of medical ethics is the right to informed consent, as individuals must be made fully aware of all the potential benefits and risks associated with a medical intervention, while still maintaining the right to decline that intervention should they so choose. [41] Mandates or coercive measures fundamentally violate historical safeguards humanity has put in place to protect us from the ever present threat of medical tyranny, including the Nuremberg Code, the United Nations’ International Covenant on Civil and Political Rights, and UNESCO’s Universal Declaration on Bioethics and Human Rights. [42] [43] [49] Such would also be in violation of the Hippocratic Oath, for not only do oath keepers pledge first to do no harm, but also to treat the needs of the patient. [44] This implies that a doctor’s duty primarily pertains to the needs of the individual before the needs of the collective, a vital distinction made by Hippocrates and understood for nearly 2 millennia. [45] [46] Privileging the needs of the collective is a “fallacy of misplaced concreteness”. [47] While individual need is directly apprehensible and consensual, collective need is an abstract, subjective concept not easily defined. And yet who usually gets to define this concept? Such is most often defined by those in power with the most means to influence institutional narratives, turning medical professionals who treat the needs of the collective according to this definition into mere extensions of that power at the expense of individual informed consent.

* Regarding the reporting on the reduction of relative risk instead of absolute risk, in the phase 3 trial of the Pfizer vaccine, for example, 22,000 people were vaccinated and 22,000 were given placebo, for a total of 44,000 trial participants. Of those 44,000, just 170 were diagnosed (via suspect application of RT-PCR tests) as having covid-19 post-vaccination. Of those 170, it was reported that 8 received the vaccine and 162 received the placebo. From this ratio it was inferred that the vaccine would prevent 154 out of 162 from getting the disease for an efficacy of greater than 90%. But even as the British Medical Journal explained, “A relative risk reduction is being reported, not absolute risk reduction, which appears to be less than 1%.” [39] The supposed sterling efficacy touted by both Pfizer and Moderna are great for instilling confidence in their product, yet they were based on figures derived from only a small fraction of trial participants (just 0.38% of total participants in the Pfizer trial, and the same misleading statistical reporting seen in the Moderna trial as well). [40]

** Labeling the mRNA technology employed by Pfizer and Moderna a “vaccine” stretches the term’s definition beyond reasonable limits. While it is true that such an intervention technically fulfills the purpose of vaccination by encouraging acquired immunity against an infectious disease, it does not contain any attenuated biologics typical of traditional vaccination; it may be more accurate, therefore, to label such as a “synthetic pathogen delivery device” constituting a form of “gene therapy”.

Links:
[1] https://en.m.wikipedia.org/wiki/Antibody-dependent_enhancement
[2] https://pubmed.ncbi.nlm.nih.gov/22536382/
[3]https://childrenshealthdefense.org/defender/pfizer-covid-vaccine-trial-pathogenic-priming/
[4] https://cvi.asm.org/content/23/3/189
[5] https://www.fda.gov/media/144245/download
[6] https://www.statnews.com/2020/03/11/researchers-rush-to-start-moderna-coronavirus-vaccine-trial-without-usual-animal-testing/
[7] https://www.sciencedirect.com/science/article/pii/S2589909020300186?via%3Dihub
[8]https://jameslyonsweiler.com/2020/12/06/susceptibility-of-people-to-pathogenic-priming-is-a-prime-reason-to-eschew-covid19-vaccine-mandates/
[9]https://childrenshealthdefense.org/press-release/fda-ignores-rfk-jr-s-pleas-for-vaccine-safety-oversight-concerning-peg-suspected-to-cause-anaphylaxis/
[10]https://www.mayoclinic.org/diseases-conditions/anaphylaxis/symptoms-causes/syc-20351468
[11]https://www.reuters.com/article/idUSKBN28J1D1
[12]https://pubmed.ncbi.nlm.nih.gov/27804292/
[13]https://childrenshealthdefense.org/wp-content/uploads/2020-10-25_Hahn-Marks-Email-from-RFK-Jr.pdf
[14]https://childrenshealthdefense.org/wp-content/uploads/RFK_Jr_Letter_toFDA-_CBER-9-25-20.pdf
[15]https://www.bitchute.com/video/256BhchLR0R6/
[16]https://www.ctvnews.ca/mobile/world/u-k-to-refine-allergy-warning-on-pfizer-vaccine-sparked-by-two-adverse-reactions-1.5223107
[17]https://www.mintpressnews.com/darpa-covid-19-vaccine-implant-mrna/271287/
[18]https://www.thelastamericanvagabond.com/coronavirus-gives-dangerous-boost-darpas-darkest-agenda/
[19]https://www.mddionline.com/implants/early-warning-system-detecting-infections-being-studied
[20]https://childrenshealthdefense.org/child-health-topics/military-vaccines/microchips-nanotechnology-and-implanted-biosensors-the-new-normal/
[21]https://www.defenseone.com/technology/2020/03/military-funded-biosensor-could-be-future-pandemic-detection/163497/
[22] https://childrenshealthdefense.org/defender/how-fda-approved-pfizer-covid-vaccine-warp-speed/
[23] https://www.scientificamerican.com/article/the-risks-of-rushing-a-covid-19-vaccine/
[24] https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-conclude-phase-3-study-covid-19-vaccine
[25] https://lbry.tv/@joe-plummer:b/fauci-happy-if-vaccine-permits-infection:5
[26] https://www.bitchute.com/video/NSil15MibqlM/
[27] https://www.bitchute.com/video/pZWlFbhngLAH/
[28] https://youtu.be/KMc3vL_MIeo
[29] https://www.bitchute.com/video/256BhchLR0R6/
[30] https://pfe-pfizercom-d8-prod.s3.amazonaws.com/2020-11/C4591001_Clinical_Protocol_Nov2020.pdf
[31] https://childrenshealthdefense.org/transcripts/how-will-we-know-that-a-covid-19-vaccine-is-safe/
[32] https://www.globalresearch.ca/dr-wodarg-dr-yeadon-request-stop-all-corona-vaccination-studies-call-co-signing-petition/5731458
[33]https://pastebin.com/t1SxR18Y
[34] https://childrenshealthdefense.org/defender/alaska-healthcare-workers-allergic-reactions-pfizer-covid-vaccine/
[35] https://childrenshealthdefense.org/defender/alaska-healthcare-workers-allergic-reactions-pfizer-covid-vaccine/
[36] https://childrenshealthdefense.org/defender/pfizer-covid-vaccine-trial-pathogenic-priming/
[37] https://childrenshealthdefense.org/news/transverse-myelitis-gardasil-vaccine-video/
[38] https://childrenshealthdefense.org/news/covid-19-vaccine-participant-develops-neurological-symptoms-astrazeneca-pauses-trial/
[39]https://blogs.bmj.com/bmj/2020/11/26/peter-doshi-pfizer-and-modernas-95-effective-vaccines-lets-be-cautious-and-first-see-the-full-data/
[40] https://thehighwire.com/videos/how-effective-is-the-covid-19-vaccine/
[41] https://www.halt.org/the-medical-ethics-of-informed-consent/
[42] http://www.cirp.org/library/ethics/nuremberg/
[43] https://www.ohchr.org/EN/ProfessionalInterest/Pages/CCPR.aspx
[44] http://rjoy4u.org/modernhippocraticoath.pdf
[45] https://patient.info/doctor/Medical-Ethics
[46] https://en.m.wikipedia.org/wiki/Hippocratic_Oath
[47] https://psychology.wikia.org/wiki/Reification_(fallacy)
[48] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4483554/#B16
[49] http://portal.unesco.org/en/ev.php-URL_ID=31058&URL_DO=DO_TOPIC&URL_SECTION=201.html
[50]https://childrenshealthdefense.org/defender/healthy-florida-doctor-dies-after-pfizer-covid-vaccine/
[51] https://childrenshealthdefense.org/defender/china-health-experts-suspension-covid-vaccines-norway/
[52] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5475249/#!po=0.510204
[53] https://www.pandata.org/letter-to-peter-marks-fda/
[54] https://www.pandata.org/science-review-denis-rancourt/
[55] https://jermwarfare.com/blog/mike-yeadon-vaccine-covid#
[56] https://childrenshealthdefense.org/defender/329-deaths-9516-other-injuries-reported-following-covid-vaccine-cdc/?itm_term=home

You're wasting your time with the Covid conspiracy theorists. They literally don't want to learn new things.

Deleted User wrote: »

Here are few predictions made by people who have been dismissed as conspiracy theorists:

1. Health passports: Currently being rolled out across the world.

2. Permanent mask-wearing: Professor John Edmunds of Sage said the other day that masks would be permanent, Biden has gone from "masks for 100 days" to "masks until at least 2022", the CDC wants Americans to wear two or three masks and to wear masks indoors and outdoors when they're with people they don't know, Professor Ash in Israel said that limitations were here to stay.

3. Permanent social distancing: Priti Patel said in May that social distancing was here to stay.

4. Masks at home: Dr. Vernon Coleman said a few months ago that masks at home was next. The CDC now want Americans to wear masks at home when they're with people they don't know.

Wow, they are things that non-conspiracy theorists also predicted. Why not talk about the amount of rubbish that conspiracy theorists have predicted and have failed to come to fruition. Broken clocks are right twice per day.

King Mob wrote: »

Cool. So what about the mandatory vaccinations that were predicted?
What about the martial law and camps for people who haven't been vaccinated?
How about the complete collapse of capitalism and the removal of the concept of ownership?
How about the abolition of paper money?
How about the tracking devices and infertility drugs hidden in the vaccines?
How about the vaccines being super deadly?
How about the literial biblical apocalypse begining.

Even if all your above claims are accurate (they aren't), stopped clocks and all that.
How about us being all forced to become cyborgs?

And whens satan arriving? I bought balloons and party poppers!

King Mob wrote: »

No, first of all address the claims you've already made.
You claimed that the vaccine has caused things like death and miscarriage.
.

People have died after getting the vaccine and women have miscarried. Whether it was because of the vaccine or would have happened anyway is debatable.

If you use the same criteria as is used for COVID deaths then death for any reason 28 days after the vaccine it would be counted as caused by the vaccine.

As for proof of these events I’ll need to dig it up but there’s one story about a pregnant doctor who miscarried just after receiving it and of course people will die. People have allergic reactions to many drugs. Whether the safety profile of these vaccines is worse than normal I cannot say. They are certainly using experimental techniques and have a strong incentive to lower safety thresholds for the greater good (or the economy)

stefanovich wrote: »

People have died after getting the vaccine and women have miscarried. Whether it was because of the vaccine or would have happened anyway is debatable.

Source please.
No one is going to take your word for it.

stefanovich wrote: »

If you use the same criteria as is used for COVID deaths then death for any reason 28 days after the vaccine it would be counted as caused by the vaccine.

That's not the criteria being used.

And if we are going back the actual criteria being used by conspiracy theorists here, none of these deaths can be caused by the vaccine as they are only deaths with the vaccine.

The UK government do not seem to recommend routine vaccination for pregnant women due to lack of data

https://www.gov.uk/government/publications/safety-of-covid-19-vaccines-when-given-in-pregnancy/the-safety-of-covid-19-vaccines-when-given-in-pregnancy

stefanovich wrote: »

The criteria in the UK is death for any reason within 28 days of a positive result or somesuch. For proof turn on sky news for the daily briefing.

No source then.
Cools.

stefanovich wrote: »

So the Covid vaccines have no risk of allergic reaction? I think the onus is on you to prove that.

Never claimed that.

Are you claiming that the risk of allergic reaction is greater than other vaccines or other medicines?

stefanovich wrote: »

As for the doctor miscarriage story, looks to be misinformation. Poor woman.

Cool. Then please refrain from repeating it in the future.

Do you have any evidence for the vaccine causing deaths?

Timberrrrrrrr wrote: »

They also advise against other vaccinations whilst pregnant, vaccines that have been around for years.

So it wouldn’t appear they are sure of its safety for pregnant women.

King Mob wrote: »

One of your two links is just refuting your previous claim that the vaccine caused a miscarriage.
The other one refers to a single case that's being investigated at the time of writing.
So POSSIBLY one death?
That's all?
Do you have any evidence for any others?

But, sorry, you seem to have dodged a few points in my post there.

You falsely accused me of saying that the vaccine would have no allergic reactions.
Why?

I also asked you if you believed that the vaccine would cause more allergic reactions than other vaccines. You ignored this question. Please answer it now and explain why you ignored it the first time.

Read the full article and get back to me.

stefanovich wrote: »

Read the full article and get back to me.

I can't as it's behind a pay wall.
If you have another source, or a source that provides evidence for more than one POSSIBLE death, please provide.

stefanovich wrote: »

Very bossy now aren’t we.

Just making it clear that you are being dishonest and avoiding points.

Why are you dodging points?
Why are you forced to do this to defend your position?

So far we've had anti vaxxers here lie, dodge and plagerise.
Do you guys ever wonder why you have to do this?

stefanovich wrote: »

Here’s a quote from the article. I believe the autopsy is ongoing.

Ok. So one POSSIBLE death.

That's all.

Like I said.
Great.

You're still dodging the other points.
Why?

Also, I did your work for you and found an alternative link.
https://www.seattletimes.com/nation-world/doctors-death-after-covid-19-vaccine-is-being-investigated/

“This is going to be very rare,” said Spivak, an emeritus professor of medicine. But he added, “It happened, and it could happen again.”

Even so, he said, it should not stop people from being vaccinated.

Weird how you left this quote out seeing as it's right after the one you pointed out.

Also:

The condition Michael developed, acute immune thrombocytopenia, occurs when the immune system attacks a patient’s own platelets or attacks the cells in the bone marrow that makes platelets. COVID itself can cause the condition in some patients.

King Mob wrote: »

Ok. So one POSSIBLE death.

That's all.

Like I said.
Great.

You're still dodging the other points.
Why?

What did I dodge? I don’t respond well to being ordered about by someone who doesn’t even bother to read up on what we are discussing and expects me to jump through hoops.

stefanovich wrote: »

You really did zero research. I suggest researching before forming an opinion.

https://www.bloomberg.com/news/articles/2021-01-16/norway-vaccine-fatalities-among-people-75-and-older-rise-to-29

Also, reading the article:

Norway expressed increasing concern about the safety of the Pfizer Inc. vaccine on elderly people with serious underlying health conditions after raising an estimate of the number who died after receiving inoculations to 29.

The latest figure adds six to the number of known fatalities in Norway, and lowers the age group thought to be affected to 75 from 80. While it’s unclear exactly when the deaths occurred, Norway has given at least one dose to about 42,000 people and focused on those considered most at risk if they contract the virus, including the elderly.

...

The findings have prompted Norway to suggest that Covid-19 vaccines may be too risky for the very old and terminally ill, the most cautious statement yet from a European health authority.

The Norwegian Institute of Public Health judges that “for those with the most severe frailty, even relatively mild vaccine side effects can have serious consequences. For those who have a very short remaining life span anyway, the benefit of the vaccine may be marginal or irrelevant.”

My mind is being cast back to the arguments that were being made that covid wasn't a danger because it was only killing those with underlying conditions and the super old.
Yet now, we're being told that the danger is super dangerous cause it MIGHT have killed 29 people with underlying conditions and who are super old.

At the same time, this article goes out of it way to state that the vaccine is only linked to these deaths because they after getting the vaccine, nothing else. In other words, they died "with the vaccine" not "of the vaccine".
But now cause it can be used to bash vaccines and science and flog an agenda, I guess this method is now suddenly valid and beyond question.

Also some other relevant quotes:

“The Norwegian Medicines Agency has communicated, prior to the vaccination, that when vaccinating the oldest and sickest, it is expected that deaths will occur in a time-related context with vaccination. This does not mean that there is a causal link between vaccination and death. We have also, in connection with the reported deaths, conveyed that it is possible that common and known side effects of the vaccines may have been a contributing factor to a serious course or fatal outcome,” the agency said.

Norway’s experience doesn’t mean that younger, healthier people should avoid being vaccinated. But it’s an early indication of what to watch as countries begin to issue safety monitoring reports on the vaccines. Emer Cooke, the new head of the European Medicines Agency, has said tracking the safety of Covid vaccines, especially those relying on novel technologies such as messenger RNA, would be one of the biggest challenges once shots are rolled out widely.