Johnson and Johnson Covid-19 vaccine linked to rare syndrome: what's the risk?

Vaccines using new mRNA technology have been linked to a number of health risks, currently thought to be negligible

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  A health worker holds a vial of the Janssen (Pharmaceutical Companies of Johnson & Johnson) vaccine against COVID-19 in Kathmandu, Nepal, 12 July 2021. The United States of America through COVAX supplied on 12 July 2021, 1. 5 million doses of Johnson & Johnson vaccine against COVID-19 to help struggling Nepal in its vaccinaton drive for its citizens. EPA / NARENDRA SHRESTHA

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  A man receives a dose of the Janssen vaccine against COVID-19 during the opening of a mobile vaccination centre for vaccination without prior registration, at the main railway station in Prague, Czech Republic, 12 July 2021. Prime Minister Andrej Babis and Health Minister Adam Vojtech opened two mobile vaccination points, in a shopping centre on the outskirts of the capital and at the main railway station in Prague. People interested in vaccination can go to these vaccination points without prior registration. About 35 percent of Czech people have completed their vaccinations. EPA / MARTIN DIVISEK

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  Nepalese workers unload boxes containing the Janssen (Pharmaceutical Companies of Johnson & Johnson) vaccine against COVID-19 in Kathmandu, Nepal, 12 July 2021. The United States of America through COVAX supplied on 12 July 2021, 1. 5 million doses of Johnson & Johnson vaccine against COVID-19 to help struggling Nepal in its vaccinaton drive for its citizens. EPA / NARENDRA SHRESTHA

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  Crew members of cruise ship Oosterdam receive a shot with the Janssen vaccine against the COVID-19 in IJmuiden, The Netherlands, 08 July 2021. It is the go-ahead to vaccinate the crew of cruise ships that sail under the Dutch flag and are vaccinated in the Netherlands. EPA / RAMON VAN FLYMEN

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  A person receives a dose of J&J/Janssen Covid-19 vaccine in an itinerant vaccionation truck sponsored by Spanish carmaker Seat in colaboration with the Catalan regional health service at the Triumphal Arch in Barcelona on july 7, 2021. (Photo by LLUIS GENE / AFP)

While Covid-19 vaccines have been credited with saving tens of thousands of lives, there have also been health scares linked to them.

The latest involves the Johnson and Johnson vaccine and a rare neurological condition, Guillain-Barré syndrome (GBS).

This week the US Food and Drug Administration added a warning about GBS to its guidelines for healthcare providers administering the vaccine, which is also known by its Janssen brand name.

Here we look at the condition and consider its apparent association with the vaccine.

What is Guillain-Barré syndrome?

Guillain-Barré syndrome, which the UK’s National Health Service (NHS) says is pronounced “ghee-yan bar-ray”, is caused by the immune system attacking the body’s nerves. Cases frequently follow a bacterial or viral infection, including influenza.

Early symptoms include numbness, weakness, pain and balance problems, which may worsen over several weeks, with the feet, hands and limbs most affected.

In some cases, sufferers find walking, swallowing and even breathing difficult, according to guidance from the NHS, and as symptoms spread, movement as a whole may prove difficult.

Various treatments are available, including blood filtering — called plasma exchange — or the administration of an intravenous substance produced from donated blood.

Hospital stays of weeks or months are typical and there is a risk of death, and some people are left with long-term complications. However, patients usually recover fully.

Children can develop the condition, although it is more common in adults, especially men, and in a typical year there are about 3,000 to 6,000 cases in the US.

Is there a link with vaccination?

According to the US Centres for Disease Control and Prevention there have been about 100 cases of GBS in the country among 12.8 million who have received the Johnson and Johnson vaccine. Of these, 95 were serious, with one fatal.

Symptoms typically developed a two weeks after vaccination and men aged over 50 were most affected.

Last month there were reports of a handful of cases of GBS in the Nottingham area of central England in people who had received the Oxford-AstraZeneca shot. Also some recipients in India and Australia have developed the condition.

The Johnson and Johnson and Oxford-AstraZeneca vaccines are based on similar technology, being viral vector vaccines made from a harmless adenovirus that delivers coronavirus genetic material into cells.

Is vaccination still safe?

While the Johnson and Johnson vaccine appears to increase the chance of developing GBS, the US data indicates that fewer than one recipient in 100,000 falls ill.

As with the Oxford-AstraZeneca vaccine, regulators have not recommended against continued use because of GBS.

“That’s a significant risk and it’s a very serious condition, but at the same time for the average person no doubt vaccination is beneficial,” said Prof David Taylor, professor emeritus of pharmaceutical and public health policy at University College London.

Balanced against the risks of vaccination are the much higher risks from developing Covid-19, which may itself be a risk factor for GBS, although findings are contradictory.

A study from last year looking at cases in England during the first wave of the pandemic found that there were actually fewer reports of the condition in 2020 compared with previous years.

However, Dubai Medical Journal earlier this year reported GBS in a 72-year-old man in Kuwait with Covid-19.

“Neurologists should be aware of GBS as a potentially serious complication associated with Covid-19,” the researchers concluded.

Are there other risks associated with Covid-19 vaccination?

The Johnson and Johnson and Oxford-AstraZeneca vaccines have been linked to a syndrome called immune thrombotic thrombocytopenia, which causes potentially fatal blood clots.

Although these are extremely rare, the risk has caused some countries to impose age restrictions on these vaccines, with younger people often offered an alternative.

Two other vaccines, the Moderna and Pfizer jabs, based on mRNA technology, have been linked to a rare type of heart inflammation called myocarditis, with teenaged boys and young men most at risk.

A report from Harvard Health Publishing earlier this month said there had been about 1,000 cases from millions of vaccine doses.

“The majority of cases have been mild. Experts are still gathering information, but as of this writing, 79 per cent of teenagers and young adults who experienced this had recovered,” wrote Dr Claire McCarthy, a paediatrician at Boston Children’s Hospital and an assistant professor of paediatrics at Harvard Medical School.

She said there was a risk of myocarditis, and other complications, from Covid-19, and the recommendation was for vaccination to continue.