Vaccine side effects are not uncommon - so, with J&J's jab: What are they, who gets them, and why?

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  • The majority of individuals vaccinated with J&J's vaccine experienced temporary mild side effects 
  • A handful of individuals experienced allergic reactions, but they were carefully monitored and have fully recovered
  • Professor Linda-Gail Bekker chatted to Health24 about what one needs to know about receiving the jab

It’s been almost two months since the Johnson & Johnson Covid-19 vaccine was rolled out in South Africa to healthcare workers. To date, close to 290 000 healthcare workers have been inoculated with the single-dose jab.

Experiencing some side effects to vaccines is not uncommon - normal signs that the body is building protection. It's also important to note that these adverse events can vary for each individual, depending on a number of factors such as general health and age. 

Health24 chatted to Professor Linda-Gail Bekker, co-lead investigator of South Africa's Sisonke Covid vaccine trial, about the side effects of the J&J jab, which, at the time of publication, was being used for the first time outside a clinical trial setting.

What have been the most common side effects?

According to Bekker, the vast majority of side effects from the J&J jab have been mild and short-lived.

“We definitely do expect some sort of reactogenicity. That means the immune system is being a little bit shaken up by the vaccine and typically, what people get is mild flu-like symptoms – perhaps even a little bit of a fever,” she said.

Soreness at the injection site, in this case, the arm, is also common, as well as fatigue and nausea, but that usually only lasts a day or two, she added. Bekker advised that taking paracetamol or even a non-steroidal anti-inflammatory agent, such as aspirin or ibuprofen, will ease most of these symptoms. 

No side effects?

On the other hand, some people may not experience any of these systemic symptoms, she explained: “They might just have a sore arm, or they might not even have such a sore arm. That is not to say they didn’t get the vaccine. It’s just that different immune systems react in different ways.”

Instead, what Bekker described is what most people will experience. There are, however, definitely outliers on both sides, she said. “There are therefore people who have very few side effects, and then there are people who have more robust experiences, and those people could actually feel quite ill for a day or two.”

The uncommon side effects 

There have also been reports of some people who have had allergic reactions to the jab, said Bekker. “Some people have had a rash, while others have had a slight drop in their blood pressure. There have also been some asthmatic individuals who felt a tightening of the chest when they got the vaccine."

In the Sisonke trial, there were a small number of individuals who experienced severe allergic reactions, and up to five of those individuals were admitted to hospital, “more for observation and precaution than anything else”, Bekker added. All five people have since recovered and are doing well. 

Update: reports of blood clots

On 13 April, Health Minister Zweli Mkhize announced that the country would temporarily suspend the J&J rollout, Health24 reported. This came shortly after the US Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) called for the pausing of the use of the vaccine, citing six cases of severe blood clots among the 6.8 million women who received the shot.

European health authorities were currently investigating the cases, leading to a delay in vaccine deployment there.

The FDA said it was recommending a temporary pause "out of an abundance of caution". It confirmed that one patient died as a result of blood-clotting complications and that another was in a critical condition. According to The Washington Post, the health agencies are investigating this possible side effect. A review is expected to conclude within days.

Bekker told Health24 the cases are "very rare". On Wednesday, 14 April, the SA Health Products Regulatory Authority (Saphra) announced that it had reviewed the data from the Sisonke study and that no major safety concerns had been identified in the healthcare workers who took part in the study.

On Saturday evening, the regulatory authority released another statement explaining that, "based on a review of available data", it recommended the pause on the Sisonke study be lifted, "provided that specific conditions are met", News24 reported. These conditions include, among others, strengthening, screening, and monitoring recipients of the vaccine who are at high risk of a blood clotting disorder.

Informing personnel of allergy history beforehand

People who are prone to allergies are requested to inform the healthcare personnel who administer vaccines beforehand. This is so that they can be observed and monitored for any allergy-related reactions around 30 minutes post-vaccination, stressed Bekker.

“We normally observe people for 15 minutes anyway, regardless of whether they have symptoms or not, but in those that have allergic responses – we want to monitor them for a bit longer. If there is no impact, they can leave just like anybody else.”

Why do side effects occur?

For people who’ve already contracted a mild case of Covid, symptoms induced by vaccination might be a very similar feeling, said Bekker. “This is because the immune system is being stirred up to respond to a viral infection, so that if the virus comes onboard, that immunity will be ready and primed to go to take on the virus.

“And so some of the feelings are reminiscent of how we felt when we got the flu, or when we had a cold, or even if we’ve had a mild case of Covid, because it’s stirring up exactly the same immune responses.” 

Symptoms coinciding with vaccination

Bekker explained that several people experienced illnesses after being vaccinated, but that these cases are always followed up so that researchers involved in the trial can confirm whether they’re related to the J&J vaccine.

“We’ve had people who had neurological symptoms, or other illnesses, for reasons unrelated to the vaccine. We followed up on each of them and their attending doctors, to assess whether it’s related to vaccination or not, or indeed, due to Covid. Because, obviously, some people may still go down with SARS-CoV-2 and we want to know if that happens.”

Some cases are still under review where a final diagnosis has not been made, said Bekker, but cautioned to bear in mind that there are many older people, as well as those with comorbidities receiving the vaccine, so other illnesses unrelated to the jab are expected.

Fewer potential side-effects than with two-dose jabs?

“Not necessarily, although some people have described that the reactogenicity is worse with the second dose. But that doesn’t necessarily hold because each person’s immune system is slightly different and does its own thing,” said Bekker.

However, what the researchers are interested in are certain side effects across the board – irrespective of which Covid vaccine it is – known as "side effects of special interest".

“This is a pre-considered list of conditions, such as Bell’s Palsy, that, if they occur, we follow them up very carefully because we want to be sure that we’re not seeing anything that is rare or troublesome about the vaccination,” explained Bekker.

Does stronger side effects mean you will have better protection against Covid?

“Again, this is not necessarily the case. It doesn’t mean that if I have a vicious reactogenicity I’m going to be better protected. It is just how my body manifests the immune response, but that doesn’t naturally mean better protection down the road.”

Side-effects may be more common and stronger in younger recipients

Younger people generally tend to have more side effects than the elderly, because young people’s immune systems are more robust, said Bekker.

“We know that as we get older, everything else also gets older. Our cells get older, our hair gets older, and our immune systems also get older. And so they can become somewhat blunted as we age, resulting in the potential that younger people may have more robust responses, or reactogenicity, than older people. We’ve seen that with the flu vaccine, for instance – that it sometimes works better in younger people than in older people.”  

*This story has been updated to reflect recent developments both locally and internationally

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