The Pfizer, Moderna and AstraZeneca Covid-19 vaccines are being linked to unexpected vaginal bleeding in older women and women on birth control. 

While changes in bleeding and periods in menstruating women post-shot have been known for years, few studies have looked at the impact on women who don’t normally menstruate, such as the elderly and those on birth control.

However, a recent study using data from thousands of women in Norway looked at the association between these vaccines and unexpected vaginal bleeding and found that in postmenopausal women, the risk of vaginal bleeding increased two to three times in the four weeks after Covid vaccination compared to before vaccination. 

In women entering menopause and premenopausal women, the risk was increased three to five times. 

Researchers looked at data from August and September 2021. Ninety-eight percent of the women included reported receiving their Covid vaccines in January 2021, meaning they had received the original Covid-19 vaccine as opposed to any updated booster shots. 

Additionally, in Norway, where the data was collected from, Covid vaccines used included those manufactured by Moderna, Pfizer-BioNTech and AstraZeneca. 

When Covid vaccines were first rolled out, tens of thousands of women complained about late or unusually heavy periods. Before formal research was conducted, anti-vaxxers latched onto the reports and used them to infuse fear in Americans that the vaccines caused infertility. 

However, research later released showed while menstrual changes do occur following Covid vaccination, they are minor, temporary and do not impact fertility. 

Experts are not entirely sure why changes in menstruation occur, but some believe the vaccine causes some of the body’s tissue to become inflamed, causing changes to the lining of the uterus and hormone levels throughout the body.  

While the recent study did not investigate why these women experienced unexplained vaginal bleeding, sometimes referred to as breakthrough bleeding, scientists did suggest it could be linked to the spike protein used in the shots. 

Study author Kristine Blix from the Norwegian Institute of Public Health in Oslo, said: ‘We had already, from the early pandemic, biweekly questionnaires going out to cohort participants to monitor effects of the pandemic. 

‘In the first questionnaire that covered COVID-19 vaccinations, sent in 2021, some women reported in free-text fields that they had experienced heavy menstrual bleeding. 

‘This urged us to ask for bleeding patterns in a structured manner.’

Researchers looked at data from nearly 22,000 women who had already experienced menopause, women in perimenopause, the time just before entering menopause, and non-menstruating premenopausal women, including some who were on long-term hormonal birth control. 

They found 252 postmenopausal women (3.3 percent), 1,008 perimenopausal women (14.1 percent) and 924 premenopausal women (13.1 percent) reported unexplained or breakthrough vaginal bleeding throughout the entire year of 2021. 

Of the women who reported this, about half in every group reported their bleeding occurred within the four weeks following their first and/or second vaccine dose. 

The data showed: 45 percent of postmenopausal women, 51 percent of perimenopausal women and 55 percent of premenopausal women reported the unexplained bleeding.

Among these women, 28 percent of those in perimenopause characterized the bleeding as heavy, compared to 18 percent of both women who had finished menopause and who had not yet experienced menopause. 

Women in the senior cohort of the study were aged 61 to 88 years old and were considered non menstruating. Other non menstruating females were aged 32 to 64 years. Respondents were then grouped into the three menopausal categories. 

Vaginal bleeding in postmenopausal women can be a sign of a serious condition, such as cancer, and more women in this group than the others sought medical care after experiencing unexplained bleeding – 30.6 percent compared to 13.8 percent of perimenopausal women and 9.3 percent of premenopausal women. 

The risk of breakthrough bleeding in the first four weeks after a dose of Moderna’s vaccine was associated with a 32 percent increase compared to Pfizer-BioNTech’s vaccine. 

Heavy menstrual bleeding has since been added as a vaccine side effect. 

The study, published this week in the journal Science Advances, analyzed data from an ongoing health survey called the Norwegian Mother, Father, and Child Cohort Study.

At this time last year, Adrian Taylor was given a devastating prognosis: he had incurable cancer in his lungs and without treatment there was a 100 per cent chance he’d die from it, potentially within months.

But now, thanks to a clinical trial for a cancer vaccine – a UK first – he says ‘that despair turned to hope. I am not dying of cancer, I’m living with it and feeling great’.

Adrian, 54, a supply chain consultant, was diagnosed with head and neck cancer in December 2021.

After undergoing gruelling months of chemotherapy and radiotherapy, a CT scan in June 2022 showed the cancer was gone in his head and neck – but revealed a 9mm tumour in his right lung. The cancer had spread and was now deemed incurable.

‘I had learnt to deal with my first cancer diagnosis, but this was shattering news,’ says Adrian, who lives with his wife, Karen, 61, in Wallasey, Merseyside. The couple have three daughters and a son.

‘It was then that the consultant said, ‘Put it this way, Mr Taylor, without treatment there’s a 100 per cent chance you’re gonna die from this’, I went into survival mode – thinking about my children, my wife, my family; I needed to be around to provide for them. It was very sobering.’

Adrian was referred back to his original oncologist to discuss his options. This time chemotherapy and radiotherapy couldn’t help as the cancer was too advanced – and further scans showed tumours spattered across his lung, so surgery wasn’t suitable.

‘One of the tumours had grown from 9mm to 25mm in a few months, suggesting it was a very aggressive cancer,’ he says.

‘I was at the last-chance saloon, staring death in the face.’ His only hope was to enrol on to a clinical trial for a new treatment.

Then, in September last year, he was thrown a lifeline – to join a trial for a cancer vaccine, a new approach that could revolutionise how the disease is treated.

The trial, at the Clatterbridge Cancer Centre in Liverpool, is for patients with head and neck carcinoma caused by HPV-16 – a third of head and neck cancers are linked to this virus. As part of the trial, patients are also given pembrolizumab – a new drug known as a checkpoint inhibitor that helps the immune system attack the cancer cells.

The hope is that the vaccine will stimulate new immune cells that will also kill off the cancer cells, effectively supercharging the immune response to the tumour.

Cancer vaccines and checkpoint inhibitor drugs are types of immunotherapy, treatments that work by harnessing the immune system – ‘they each target different aspects of cancer biology’, says James Spicer, professor of experimental cancer medicine at King’s College London.

Adrian was referred to the trial team by his consultant. ‘I saw them a few weeks later and they said I was eligible – I had the first dose in November, and go back every three weeks for more doses and have scans every eight weeks,’ he says.

‘A CT scan before the trial started showed at least six tumours across the right lung that were up to 25mm wide and they were growing quickly.

‘In May, I sat with an oncologist who looked at the latest scan, shook his head in disbelief and said, ‘This is remarkable’. He showed me the images – there had been a massive grey patch in my lung before the trial, indicating cancer, yet now it looked clear. It felt surreal. Last week’s scan showed there was just one final bit of cancer left – the largest, 25mm tumour had shrunk to just 4.6mm.

‘I feel reborn and I’m doing things I never thought I’d be able to: I walked my daughter down the aisle in November and have seen two of my children graduate in the past year. I feel fantastic and positive about the future again.’

Adrian will receive the vaccine regularly for as long as he is also having pembrolizumab; currently, this is capped at two years.

He is one of the first in the UK to benefit from a cancer vaccine.

Unlike vaccines given to prevent infectious diseases, such as Covid, in cancer they work primarily as treatments, given to patients with the disease to stop it returning.

The vaccines can either be off-the-shelf (see story on the right) or tailor-made to target the patient’s unique cancer based on its genetic make-up.

Once injected, the theory is that these vaccines prepare the immune system to recognise specific proteins in cancer cells so that the body can destroy them.

Professor Christian Ottensmeier, a consultant oncologist and director of clinical research at the Clatterbridge Cancer Centre and who treated Adrian, says: ‘With a vaccine, it’s a little bit like you want to train a sniffer dog to find a particular scent – you’d hold a rag under their nose with that scent and then tell them to go and find it.

‘A vaccine is a way to train our new immune T cells – our sniffer dogs. In Adrian’s case it is quite remarkable that the training has been so successful and his cancer has shrunk enormously.

‘His progress is beyond what I expected – we are all delighted and cheering him on. Success like this colours my thinking about what is possible and how a vaccine can turn things around.

‘It is early days for this type of cancer treatment and not everyone will have such a remarkable reaction to it, but we are very excited about the possibilities.’

Those possibilities for cancer vaccines are huge, experts told Good Health, with potential to treat every type of cancer.

Currently, as well as head and neck cancer, there are vaccine trials under way in the UK for prostate and colorectal cancers, and melanoma (skin cancer). A trial in lung cancer is about to start, too.

There are six cancer vaccine trials at the Clatterbridge alone – and the UK has the potential to be a leader in terms of cancer vaccine research, after the Government signed a partnership with BioNTech to support trials for the treatment; 10,000 patients should receive individualised vaccines, designed specifically for them, by 2030, it was announced in July.

Recruiting patients to these trials will be helped by a new cancer vaccine ‘launch pad’, a national network of hospitals being developed by NHS England to identify patients eligible for vaccines. The launch pad will ensure patients are able to access these trials irrespective of which hospital they’re being treated at.

A number of other companies are said to be in talks to set up cancer vaccine trials in the UK, including Moderna and Merck.

‘This new funding and deal between BioNTech and the Government means more clinical trials will be launched to test personalised cancer vaccines,’ says Dr Renato Baleeiro, an honorary senior research fellow at the Barts Cancer Institute, Queen Mary University of London, who is developing a vaccine against triple negative breast cancer. ‘The UK is one of the world leaders, with several ongoing and scheduled trials.’

So how do cancer vaccines work? The basic technology is the same pioneering mRNA approach used during the pandemic to give us the Moderna and Pfizer-BioNTech Covid-19 jabs.

MRNA is the genetic blueprint that instructs cells to make proteins in the body.

For Covid, the mRNA vaccine instructed cells to make the spike protein found on the surface of the virus itself. After vaccination, cells begin making the spike protein, ‘training’ the immune system to recognise it and then to make cells that fight it – if you later become infected with the Covid virus, these immune cells are ready and primed to fight it.

With cancer, if scientists already know which protein causes it, they can use an ‘off-the-shelf’ mRNA vaccine that instructs cells to make that protein – or they could make a personalised vaccine based on a patient’s particular tumour.

First, a sample of a patient’s tumour is analysed to identify any genetic mutations in proteins that are responsible for its growth.

Then a tailor-made molecule of the mRNA that instructs cells to make that tumour protein, known as a neoantigen, is produced.

This is injected into the patient, prompting new cells to make these tumour proteins, which then train new immune cells that mount a response. The theory is that the immune system is then primed to recognise and destroy the cancer.

The concept of vaccinating against cancer has been around for decades, but hasn’t been particularly effective until now, says Professor Spicer.

‘You’ll find a lot of studies showing vaccines can induce a detectable immune response in blood – but this hasn’t then translated to tumour shrinkage.’

In the past decade, new technology such as genome sequencing and a better understanding of the immune system and how it recognises and destroys tumours have led to better vaccines.

‘We’re finally moving from that theoretical activity – i.e. knowing it’s possible to educate the immune system to recognise and kill a cancer – to something that’s clinically meaningful which patients might benefit from,’ says Professor Spicer.

Professor Ottensmeier agrees, and says new immunotherapy drugs have given the field of cancer vaccines a massive push.

‘Drugs such as nivolumab and pembrolizumab are good at ‘waking up’ immune cells that are already able to attack the cancer – but they don’t train new cells to do the same; that’s where the vaccines come in,’ he says.

Professor Spicer argues that, strictly speaking, the mRNA cancer vaccines shouldn’t be called vaccines at all: he’d call this field ‘RNA therapeutics’. ‘Conventionally, a vaccine is useful for creating an immune response before the body meets the invader, such as the Covid virus,’ he says. ‘With cancer, we are generating an immune response for something that’s already in the body – helping it fight something it couldn’t before.

‘For example, you’re taking patients who have had surgery for colorectal cancer; you have taken out the tumour but there’s a high risk of it coming back because tiny metastatic cells are left behind.

‘Instead of waiting for it to grow, we’ll now take the removed tumour, sequence its genetic code, prepare an mRNA vaccine that makes the abnormal proteins, and inject it into patients – so the immune system learns to recognise and fight that protein, should it encounter it again.

‘That’s the Holy Grail of cancer treatment – and it’s completely bespoke for each patient.’

As all cancers are driven by genetic mutations that help them attack cells, grow and spread, this treatment approach really could help anyone – ‘there’s no type that’s off the table in theory,’ says Professor Spicer.

A number of personalised cancer vaccine trials have reported promising results so far. For example, more than three-quarters of melanoma patients with high-risk disease treated with a personalised vaccine and immunotherapy had recurrence-free survival 18 months later, compared with 62.2 per cent of those who received immunotherapy alone, it was reported at the American Association for Cancer Research conference earlier this year.

And a trial of an mRNA vaccine for pancreatic cancer – one of the most aggressive types — at New York’s Memorial Sloan Kettering Cancer Center showed it prevented or delayed relapses in about half of the 16 patients involved, reported the journal Nature in May (a trial is underway with 260 patients).

Leading UK trials into colorectal cancer is Robert Jones, a consultant liver surgeon at Liverpool University Hospitals NHS Foundation Trust. ‘We can now take out a tumour, sequence the genetic code in that cancer to identify the relevant mutations and make the vaccine for that specific patient in about seven weeks,’ he says.

The vaccines are then given as a simple jab. Different trials are investigating different protocols; while some deliver two, three or more doses of a given vaccine after surgery and chemotherapy (the 165 patients taking part in the Liverpool-led trial for colorectal cancer, involving 12 centres across the UK, will be given 12 doses), others are more ongoing. As well as being personalised to the patient’s cancer, another advantage is that the vaccines don’t have the side-effects of conventional chemotherapy and radiotherapy.

Professor Ottensmeier explains: ‘With radiotherapy, the rays have to go through skin, muscle, bone and other tissues and can’t work out what is cancer and what isn’t – so it causes the same damage to all cells in its way. It’s a similar issue with chemotherapy. It’s a poison to dividing cells and so many of them die, which is why patients develop side-effects such as a sore mouth, diarrhoea and a low blood count. These poisons aren’t selective. But the vaccines avoid all these side-effects.’

Adrian’s experience is testament to this: ‘I found chemotherapy and radiotherapy very tough, both physically and emotionally. I stopped work for eight months – my saliva glands were destroyed, I couldn’t eat or drink anything and I lost 4-6st in weight.

‘But with the cancer vaccine, it’s simple and easy: I turn up, they put a cannula in my hand and I sit there for two hours or so while they monitor me.

‘I might need paracetamol to control my temperature but, apart from that, there are no side-effects: I feel completely fine afterwards, and I’ve continued to work throughout.’

So far there are very few downsides to cancer vaccines, experts say. ‘Because we used the mRNA platform during the pandemic, we know what could go wrong – the main side-effects are soreness where it is injected, and fever [part of the normal immune response],’ says Professor Ottensmeier. ‘It breaks the mould – we are used to saying we can control the disease for a while, but it may be a hard walk to walk [owing to chemo side-effects].

‘Now we can say we could induce good clinical effects, and won’t make you ill in the process – you can get on with your life; it’s astounding to be able to say that.’

There are even talks to explore whether a cancer vaccine could one day prevent cancer developing in the first place – but in keeping with his sniffer dog analogy, Professor Ottensmeier says the challenge here is that ‘not all cancers smell the same’.

‘Those at high risk of developing cancer again or who have a genetic abnormality that’s likely to cause cancer, will be the first to benefit,’ he says. ‘But if it works, we could, in principle, open trials down the line and study it as a preventative vaccine.’

Professor Spicer adds: ‘If we found one dominant gene is effective at secondary prevention and killing of a specific cancer, such as breast for instance, we could explore whether we can roll out the vaccine to everyone to see if it reduces incidence in general. Who knows, at the rate of progress we have seen, in my lifetime we might see that.’

One of the challenges will be the logistics of rolling it out more widely – as Professor Spicer explains: ‘It’s doable but more complicated than a standard pharmaceutical.’

Dr Lennard Lee, an associate professor in cancer vaccine research at the University of Oxford, is more optimistic: ‘Can our country deliver vaccines at pace for cancer? Yes, we’ve proven we have the infrastructure during the pandemic response . . . A bit of sequencing for the bespoke vaccines means we need to step things up, but we are already doing it and proven we can with other personalised therapies.’

The bespoke vaccines will be more costly owing to the genetic sequencing required and various steps in making a personalised for each patient. But Dr Lee notes that this is not necessarily a barrier because other new cancer treatments are expensive and still used.

Meanwhile, Adrian is intensely grateful to the team at Clatterbridge. He says: ‘I feel proud and privileged to be taking part in research which could change cancer treatment for ever.’

Off-the-shelf version for patients with breast cancer 

Two types of cancer vaccines are being developed. There are ‘personalised’ vaccines, tailor-made for an individual patient’s specific cancer, based on the patient’s genes (see main piece), and ‘off-the-shelf’ ones.

Off-the-shelf vaccines are designed using the proteins that cause most cases of a particular type of cancer, explains Dr Lennard Lee, an associate professor in cancer vaccine research at Oxford University.

‘There will be a role for both types of vaccine,’ he adds.

James Spicer, professor of experimental cancer medicine at King’s College London, says: ‘From what we know so far, we’ll probably have an ‘off-the-shelf’ vaccine for melanoma or stomach cancer, for instance, because we’ve identified the most commonly mutated proteins in these types that occur in a high proportion of cases.

‘Off-the-shelf options are scalable and practical because you can manufacture them like any pharmaceutical and have them ready when a patient comes in. With personalised vaccines, there is an added complexity as you need to make one for each patient and they have to wait weeks or months – and sometimes patients cannot wait.

‘Then again, an off-the-shelf vaccine is not personalised, and so who knows if it’ll work?’

In fact, there is early evidence that off-the-shelf vaccines could work for some people, at least.

Mother-of-three Jennifer Davis, a 46-year-old nurse from Ohio, received an ‘off-the-shelf’ vaccine against triple negative breast cancer in October 2021.

She’d been diagnosed three years earlier and underwent chemotherapy, radiation and a double mastectomy.

‘I was told it was a fast-growing and aggressive cancer,’ she told Good Health. In general, triple negative is more aggressive, harder to treat and more likely to come back than other types of breast cancer.

After finishing treatment, it was ‘a waiting game to see if it would come back’, she recalls.

At one of her follow-up appointments, a nurse practitioner mentioned a vaccine that had been created for her type of breast cancer, with the potential to stop it coming back entirely.

‘But it was still in laboratory tests, and it wasn’t until September 2021 that it was ready for human studies.’ As a recent scan showed no signs of recurrence (this was one of the criteria for enrolment), Jennifer was accepted on the study.

She says: ‘I asked: ‘How many times did they see mice die or have terrible reactions after the jab? And of those that received the vaccine, what proportion saw recurrence of cancer?’

‘The answer to both was zero. So that October I received the first of three doses, two weeks apart. I had no side-effects: it was just like a regular jab.’

The idea is that the protection from three doses lasts a lifetime. Preliminary results released in April showed all 14 women given this vaccine built an immune response – meaning their bodies were, in theory, prepared to identify and kill the tumour should it return.

‘I’m almost at five years since remission and I’m living a normal life,’ says Jennifer.

The vaccine she was given is based on research by the Cleveland Clinic, which identified a protein called alpha-lactalbumin that shows up in many forms of breast cancer, including triple negative.

The research focused on the ‘retired protein hypothesis’, identifying proteins that are known to be expressed in normal tissues only at specific times, but that are expressed in some cancers outside these normal times, explains George Thomas Budd, a professor of medicine at the Cleveland.

For example, alpha-lactalbumin is only expressed in lactating breasts (i.e. when breastfeeding) – or in cases of breast cancer. ‘Targeting this protein seems to delay and prevent development of cancer in mouse models,’ says Professor Budd.

‘In the recent study, we could see immunologic responses in the majority of patients. It tells us the immune system is seeing the protein and responding to it – we are now defining the dose for future trials.’

First the anti-vaxxers jumped on Christian Eriksen, alleging the Covid vaccines were to blame when the Danish footballer suffered a cardiac arrest at Euro 2020. 

Then, less than 12 months later, they claimed Pfizer‘s ‘clot shot’ was behind Australian cricket icon Shane Warne‘s sudden heart-related death.

And when NFL safety Damar Hamlin suffered a cardiac arrest during a Buffalo Bills match in January, so-called ‘truthers’ brandished it as the icing on their Covid conspiracy cake.

Now, however, the anti-vaxx mob have a new target: Bronny James, son of legendary NBA hooper LeBron.  

The 18-year-old, expected to follow in his father’s footsteps, was rushed to hospital on Monday after suffering a cardiac arrest during practice at the University of Southern California.

Despite it being unconfirmed when, or if, Bronny had a Covid jab, critics were quick to establish a potential link.

Even Elon Musk chipped in, fuelling the conspiracy even further. 

Posting on Twitter under a news story about Bronny’s cardiac arrest, Musk wrote: ‘We cannot ascribe everything to the vaccine, but, by the same token, we cannot ascribe nothing. Myocarditis is a known side-effect. The only question is whether it is rare or common.’

But leading doctors have dismissed the theory.

Two facts — both of which are widely misinterpreted — are central to the claims. 

One is that mRNA jabs, like Pfizer’s and Moderna’s, can cause myocarditis, an extremely rare complication that causes inflammation of the heart muscle. Young people, especially boys, are most at risk.

The other? That heart-related deaths are massively above levels seen pre-pandemic. 

Cardiologists and heart health charities say conflating the two is not only incorrect, but irresponsible. 

No drug is risk-free. And while there is a very small chance of developing myocarditis from a Covid vaccine, experts insist the benefits, in the form of the tens of thousands of lives saved, clearly outweigh any potential dangers. 

Myocarditis can, in some cases, damage the pumping function of the heart, leading to disturbance issues later in life.  

But an overwhelming majority of vaccine-induced myocarditis cases are mild, real world evidence shows.  

Symptoms generally appear within a week of being jabbed and most patients make a full recovery shortly thereafter, according to the British Heart Foundation. 

The charity, which has funded various projects into the hugely controversial topic, also insists there is no evidence vaccine recipients are at increased risk of cardiac arrest afterwards, regardless of whether it is days, or months, later.

Any such link, they argue, would have been spotted by now, given that the jabs — delivered to billions across the world — were first rolled out almost three years ago.

Infections, including Covid itself, can also trigger myocarditis. This, experts argue, is a point conveniently dismissed by anti-vaxxers. 

Challenging the second point, that cardiac-related deaths are massively above pre-pandemic levels, proves trickier.

Data undisputedly shows an uptick in England since the unprecedented virus crisis began.

Even the BHF acknowledges there have been nearly 100,000 excess cardiovascular disease deaths since the beginning of the pandemic.

Yet, when broken down by age, overall death rates among young men have not risen significantly compared to pre-pandemic levels — debunking one of the main anti-vaxxer theories that swathes are being mercilessly laid low by jabs.

And they claim the rise in excess deaths, most obvious among over-45s, is partly down to the ailing state of the NHS. 

Delays in heart health screening during the pandemic, knock-on disruption of Covid lockdowns themselves, and poor ambulance response times are just some obvious factors at play. 

A BHF spokesperson said: ‘Every second counts when someone has a heart attack.

‘Average ambulance response times for suspected heart attacks and strokes have been above 30 minutes in all but one month since the beginning of 2022, and in December 2022 they even breached 90 minutes.’

They added: ‘The pandemic has caused significant disruption to the detection and management of conditions that put millions of people at much greater risk of a heart attack or stroke, like high blood pressure.’

Experts also suspect the lingering health impacts of Covid could have also played a role in total excess deaths 

A study from January found people who got infected before the vaccine roll-out were 40 per cent more likely to develop cardiovascular disease, and five times more likely to die in the 18 months after infection.

So, what about data showing heart-related deaths in younger men, the group at the centre of concerns about myocarditis risk, have shot up since the pandemic kicked off?

Well, rates were either highest in 2020 — or no different to levels seen pre-Covid, according to data collated by the Office of National Statistics (ONS).

Rates for young cardiac deaths, defined medically as a person under 35, have since fallen to around pre-pandemic norms. 

Then, what is to blame for what feels like a spate of cardiac emergencies among stars of the sporting world? Undeniably, before Covid, instances similar to Bronny’s felt few and far between.

In fact, the only high-profile incidents involved footballers Marc-Vivien Foé and Fabrice Muamba, who both collapsed on the field due to a cardiac emergency nine years apart, stick out in people’s memory, though over a dozen high-profile incidents, mainly in America, have also been recorded in the past 40 years. 

Renowned experts in cardiac health issues in young athletes told MailOnline bluntly — there has been no rise in deaths, or incidents, since Covid vaccines were put out en masse. 

A 2012 study in the journal Circulation found that a young athlete dies of a sudden cardiac event every three days on average in the US, totalling between 100 to 150 fatalities each year. 

Dr Raghav Bhatia, research fellow at the globally respected cardiovascular clinical academic group at St George’s University of London — one of the world’s most renowned sites in this specialist branch of cardiology — said: ‘There is no published literature that supports this claim.

‘A clear distinction needs to be made between peer-reviewed robust medical literature and hear-say or individual case-reports, which are often found on social media and may often represent misinformation.’

Usually, these are down to undetected cardiac problems, he said.

For example Eriksen’s collapse was pinned on an undetected ventricular fibrillation, a heart rhythm disruption.

Meanwhile, Hamlin’s was down to case of commotio cordis, where the heart stops due to a high velocity impact from an object like a ball to the chest.

Dr Bhatia added: ‘The most important thing to remember is that, in the absence of the individual concerned coming out and talking about their experience, one should not speculate.

‘Often the underlying cause and onward management may take time.

‘Speculation is often a source of disinformation and may lead to unintended consequences.’

Campaign group the Center for Countering Digital Hate said anti-vaxx groups are latching on to such incidents to promote their message despite, in many cases, it not even being known if the person in question was vaccinated.

Imran Ahmed, the group’s chief executive, said: ‘Online anti-vaxxers are parasites, cynically exploiting tragedy to baselessly connect any injury or death of a notable person to vaccinations.’

On Musk specifically, he added: ‘It is particularly worrying that Twitter has rolled back its policy on Covid disinformation to reflect Elon Musk’s desperate need to prioritise controversy, engagement, and short-term advertising profits over the public good.

‘Anti-vaxx lies are deadly and platforms must stop allowing dedicated spreaders of disinformation from abusing their platforms and the trust of other users.’

Warne’s death in Thailand at the age of 52 in 2022 was caused by coronary artery atherosclerosis, a thickening of the arteries in the heart, that led to heart attack. 

While speculation ran rife on social media that his death was linked to a Covid vaccine, there is no proof this was the case. 

Cardiac events are more common in male and black athletes, experts say, as well as in sports considered high intensity with ‘start-stop’ activities, like basketball. 

The cause of Bronny James’s cardiac event and his vaccination status are unknown.

But he checked out of the intensive care unit within 24 hours of his admission to hospital and he is currently in stable condition, a spokesman for the James family confirmed. 

Fellow athlete, and cardiac arrest sufferer Hamlin, sent his prayers to Bronny on news of the 18-year-olds collapse.

Global reports of myocarditis following Covid vaccination, particularly in young men, spooked health chiefs in 2021, when the vaccines first started being dished out to younger demographics. 

But rates in Britain were eventually found to be lower than in the US and Israel, where concerns peaked.

Some experts attributed this to the UK’s longer intervals between doses, eight weeks compared to four, and this giving the body greater time to recover. 

This, followed by data showing the risk of myocarditis from a jab was much lower than that from a Covid infection itself, led to the jabs continuing to be recommended.

British data on vaccine safety is gathered through the UK Government’s Medicines and Healthcare products Regulatory Agency (MHRA). 

Its latest report, from November, found there had been 851 reports of myocarditis following a Covid vaccination in the UK since the start of the rollout, of which 15 were fatal. 

Considering the millions of jabs that have been dished out to Britons, this provides an overall risk of 10 suspected cases of myocarditis per million doses.

Yet this is likely to be an undercount because not all cases would have been logged or reported to official channels, though reports don’t necessarily mean a confirmed case. 

The MHRA states that studies show the risk of myocarditis from contracting the virus itself has been estimated at about 1,500 cases per million patients.

Officially less than 100 deaths from Covid vaccines have been recorded the UK. Only a tiny fraction, about three, occurred in under-30s. 

While such deaths are tragic, they pale in comparison to the almost 230,000 lives estimated to have been saved by Britain’s historic Covid inoculation campaign.

And that’s not to mention the knock-on benefits, with jabs credited for ending the cycle of paralysing lockdowns that crippled the economy and the NHS.   

Globally, Covid vaccines have been credited with saving almost 20million lives during the first year of their existence.

Like with any medication or vaccine, however, the jabs do have risks. The majority are mild, such as a sore arm, flu-like symptoms and headaches.

Some concerns were raised after vaccines were found in extremely rare cases to trigger myocarditis and pericarditis — inflammation of the heart — especially among young people.

But leading heart experts insist the majority of cases are mild and temporary, and that contracting the virus itself can also cause the condition.

So what is the risk of getting myocarditis or pericarditis after the vaccine? How would I know if I had any heart damage? And is the vaccine safe for people with heart conditions or taking heart medications?

We asked two leading experts to put these fears to bed and debunk the biggest heart myths around Covid vaccinations. 

Since 2020 has there been an increase in heart-related deaths?

Yes. A report by the British Heart Foundation in November revealed that there has been just over 30,000 excess deaths involving heart disease in England since the start of the pandemic.   

This is, on average, over 230 additional deaths a week above expected.

However, causes of this ‘relate to being unable to access care for high blood pressure, heart tests and treatment for heart disease,’ according to Dr Martin Lowe, a consultant cardiologist at St Bartholomew’s Hospital, London and consultant paediatric cardiologist at Great Ormond Street Hospital, London.

He said the possible effects of Covid on the heart may also be to blame. 

Now Covid’s threat has been drastically blunted, the virus is no longer thought to be a driving force behind the excess heart disease death rate. 

Instead, ‘significant and widespread disruption to heart care services’ — including rapidly rising ambulance response times and ‘unacceptably long waits for diagnosis and treatment of conditions’ — is to blame, the BHF warned. 

NHS data also shows 2million fewer people were recorded as having controlled hypertension in 2021 compared to the previous year. 

Modelling indicates that this reduction in blood pressure control could lead to an estimated 11,190 and 16,702 additional heart attacks and strokes, respectively, over a three year period. 

Can the vaccines affect the heart?

In short, yes. 

Although it is ‘very rare’, an increased risk of myocarditis and pericarditis has been found with mRNA Covid vaccines — such as Moderna or Pfizer/BioNtech.

Myocarditis is inflammation of the heart muscle, while pericarditis is inflammation of the lining around the heart, also known as the pericardium, he added. 

But, the majority of cases that occur after vaccination ‘are mild with a complete recovery’, Dr Lowe said. 

Only in ‘extremely rare’ cases of severe myocarditis do people require hospitalisation and treatment, he added. 

‘Importantly, most people who get myocarditis or pericarditis have mild disease and the vast majority make a complete recovery, even children,’ said Professor Amitava Banerjee, an honorary consultant cardiologist at University College London.

How common is that side effect? 

The risk is low. UK data suggests a risk of one case in every 20,000 vaccine doses in most studies’, Dr Lowe added.

Those aged 18-29, particularly young men, appear to be at higher risk. And it is most common after the second dose. 

But a 2022 review on myocarditis and pericarditis following vaccination, published by the University of Alberta, found there were up to 15 cases recorded per 100,000 young men.  

A 2021 review carried out by the US Centers for Disease Control and Prevention also showed that per million second doses of mRNA Covid vaccine administered to men aged 12–29, it may trigger between 39 and 47 expected cases of myocarditis.

However, it would also prevent 11,000 Covid infections, 560 hospitalisations, 138 intensive care hospital admissions and six deaths. 

The Medicines and Healthcare Products Regulatory Agency (MHRA) asks doctors to report side effects via its ‘Yellow Card’ scheme.

According to latest figures shared by UKHSA, as of November 23 the MHRA had received 851 reports of myocarditis and 579 of pericarditis linked to the Pfizer vaccination. 

By comparison, there were 241 reports of myocarditis and 226 reports of pericarditis linked to Oxford’s AstraZeneca jab and 251 reports of myocarditis and 149 of pericarditis, with Moderna.

‘It is important to note that Yellow Card data and similar vaccine surveillance data from other countries cannot be used to compare the safety profile of Covid vaccines as many factors can influence reporting,’ UKHSA said.  

How would I know if I had myocarditis after the vaccine? 

For the majority of people who suffer myocarditis, ‘the symptoms are mild’, Dr Lowe said. 

Symptoms generally appear within three to five days, and usually no more than a week after having the vaccine. 

If people experience these symptoms, especially if they do not go away, medical help should be sought. 

‘Severe chest pain, heart failure symptoms such as breathlessness, and dangerous changes in heart rhythm that cause episodes of collapse are rare, but require urgent assessment and treatment,’ Dr Lowe added. 

Other symptoms could also include signs of a viral infection such as body aches, fever and a sore throat, Professor Banerjee said. 

Cases of myocarditis are only diagnosed after proper assessments by specialists. 

Treatment of myocarditis depends on the symptoms experienced, but can include painkillers for the chest pain or medication to calm the inflammation, as well as drinking plenty of fluids and resting. 

Do the benefits of vaccination outweigh the potential risks of myocarditis and pericarditis? 

‘Absolutely yes. Anybody who says otherwise does not understand how to analyse the data,’ Professor Banerjee said.  

‘The risk of heart disease after Covid is much greater than the risk of heart disease after vaccination,’ he added.

Among people hospitalised with Covid, around one in 50 people per year will have pericarditis, he said.

Covid also carries a risk of myocarditis – and one that is far higher than the vaccine, at 1,500 cases per million infections. 

‘Other cardiovascular disease, such as heart failure, is more common and the associated risk is much higher with Covid,’ he said.   

‘Thankfully the vast majority of the these patients have mild heart inflammation only and make a full recovery,’ Dr Lowe added.  

Some people have reported feeling a faster heartbeat in the days after their Covid vaccine. This can be part of the body’s normal immune response to the vaccine and is not normally a cause for concern. 

Is the vaccine safe for people with heart conditions and taking heart medications or blood thinners like warfarin, clopidogrel or other antiplatelet drugs?

Yes. People who have heart conditions or who take heart medication such as anti-hypertensives or statins should still get the Covid vaccine, both experts said.  

They ‘absolutely’ agree that the vaccine is ‘safe and effective’ for people who take blood thinning medication.

It is ‘indeed recommended to protect against the effects of Covid infection’, Dr Lowe said. 

For people with heart diseases, chronic kidney disease or other chronic conditions and those over the age of 70, ‘vaccination is especially important’, Professor Banerjee added, as their risk of hospital admission from Covid is higher.