Leonard Cronin said he was “completely surprised” at how unwell he felt after his first dose of the AstraZeneca vaccine.
“I get the flu every year and I never react,” Mr. Cronin said.
“It’s not a little cold or tired.
“Bad flu symptoms: really sick.”
Mr. Cronin, 72, said he was “first in line” to be vaccinated two months ago when he qualified.
He was vaccinated around 11:30 a.m. and he felt well until 2:00 a.m. the next morning.
“There’s just this horrible feeling of the flu,” Mr. Cronin explained.
“I spend most of the day in bed.”
Mr. Cronin reported that the symptoms disappeared when he woke up after falling asleep the second night, almost 45 hours after the vaccination.
And although Mr Cronin still urges all qualified Australians to get their vaccinated as soon as possible, he urges people to plan a day of recovery.
“Maybe you have a bad reaction to the flu and need to be ready to leave the next day or two,” he said.
“Make sure you don’t have any big commitments.”
AusVaxSafety often shows symptoms
Mr. Cronin’s experience is far from remarkable.
The National Center for Immunization Research and Surveillance (NCIRS) is conducting an ongoing vaccine study, called AusVaxSafety, that tracks safety data on all COVID-19 vaccines in Australia.
About three days after your vaccination, you will be sent a text message or contacted from your GP or health service asking if you are experiencing or not experiencing symptoms.
Tanan, 183,543 Australians took part in the national survey reported an adverse event (most of these mild symptoms) after a single dose of AstraZeneca.
The figure represents 56.4 percent of people vaccinated with AstraZeneca who participated in the survey following their first dose.
After their first AstraZeneca jab, nearly one in five (17.7 percent) people said they missed work, study, or other routine activities because they felt unwell.
The most common symptom is fatigue, followed by headache and muscle or body pain.
In general, Australians are more likely to have a day off from work to recover after their second Pfizer vaccine than the first or second dose of AstraZeneca.
Nearly one in four people (22.9 per cent) with a second dose of Pfizer in Australia reported missing work, study, or other routine activities.
Nick Wood from the faculty of medicine and health at the University of Sydney, said it was unclear why so many people were unable to work.
“What’s the thing they’re most worried about that they can’t go to work?” According to Dr. Wood.
“Right now, we’re interviewing people to find out.”
What causes the side effects of the vaccine?
Griffith University virologist Johnson Mak said it’s normal to feel lazy or not well post-vaccine.
“Discomfort is part of the resistance response,” he says.
“The good thing is that any discomfort caused from the COVID-19 vaccine will generally go away within 24 hours.”
According to NCIRS, people can expect most side effects to resolve within one to three days after they are vaccinated.
There are two main distinct adverse reactions in our body to vaccination: local side effects (such as redness or swelling of the injection site) and systemic ones (such as headache and fever).
Professor Mak explains the local adverse effects caused by the body that send immune cells to the location of “damage” to prevent invaders.
And systemic side effects occur after the vaccine is started that stimulates the body to develop spike protein resistance.
Dr Wood says it includes the production of proteins called cytokines, which cause inflammation and side effects such as headaches and muscle aches.
“It’s really amazing when you think about it. You get 0.5 mL injected … and this inflammatory response happens,” he said.
Professor Mak added that headaches are a way to tell our body that we need to act quickly to help the healing process.
He said considering the effects of the vaccine is under the mind, normal for anyone to feel anxious about symptoms.
“The fact that we’re all bombarded with news related to SARS-CoV-2, it’s only natural that we might not grow up exaggerating our responses and concerns,” he said.
A unique side effect of the AstraZeneca vaccine is a condition called thrombosis with thrombocytopenia syndrome (TTS).
“We don’t yet know enough about the cause of this blood clotting effect,” Professor Mak said.
But he said that as time goes on, doctors learn a lot how to detect and treat the condition.
Why do some feel worse than others after the vaccine?
Professor Mak says many factors are at play: including our genetics, how healthy we are, how sensitive our immune system is and stress levels.
“The same vaccine can affect people differently just because we’re all different,” he said.
Katherine Gibney, an infectious physician and medical epidemiologist at the Doherty Institute, says some broad guidelines are starting to come out with COVID-19 vaccines.
“People who are younger seem to have more side effects after the vaccine, women report more side effects, and people with COVID [infections previously] as if there is more impact, “he said.
Dr Gibney said young people have a much stronger immune system, which may explain why they have a stronger response to the vaccine itself.
However, he added that there is no evidence linking the seriousness of the effects to how well a vaccine will work.
Why side effects after different doses?
AusVaxSafety data reflects findings from clinical trials, in which people showed multiple side effects with the first dose of AstraZeneca and the second dose of Pfizer.
“The AstraZeneca vaccine contains an adenovirus vector, which they use to deliver the genetic payload that makes up the spike protein,” Dr Wood said.
Scientists chose a chimpanzee adenovirus, not a human, to make sure it had not been detected in the body and had a strong immune response.
“The first time you see this adenovirus you get a strong resistance response but after you get the second one, your body says‘ Hey, I’ve seen this before. ’” Dr. Wood said.
It’s not yet clear why so many people are reporting side effects after the second dose of Pfizer, but Dr. Gibney thinks the first dose may be the first for the body to act faster on the second dose.
Experts are urging Australians to get vaccinated
Dr Wood said instead of worrying about AusVaxSafety data, Australians should make sure health experts collect data in real time and report it clearly.
He encouraged people to use the information as a guide, and plan their vaccinations on more quiet days, if they feel unwell afterwards.
If you have symptoms, you can join the AusVaxSafety study by replying to a text message, or you can report your symptoms directly to the TGA.
All three experts, including Mr Cronin, said Australians should be vaccinated with any vaccine they qualify for as soon as possible.
Mr. Cronin said he was expecting his second dose of AstraZeneca in about four weeks. Despite the emotion she felt, she said she wouldn’t hesitate to do it all.
“As for the community, we need to consider not only our individual needs, but the needs of the community,” he said.
“It’s very important.”