- All three US-authorized coronavirus vaccines can cause mild to moderate side effects.
- Johnson & Johnson’s pills usually have fewer side effects than Pfizer or Moderna.
- In all three clinical trials, the elderly had fewer adverse reactions than the young.
- Check out more stories on Insider’s business page.
If you are being vaccinated, expect a sore arm.
Of all three coronavirus vaccines approved in the United States, pain at the injection site is the most common side effect.
Generally, vaccines have mild to moderate side effects that last no more than a few days. Side effects usually appear within 12 to 24 hours after shooting. They are usually a sign that the body is strengthening its immunity to viruses.
Dr. Vivek Cherian, a physician in Baltimore, told insiders: “It’s important to remember that when people get side effects from a vaccine, it’s not really because of the vaccine; it’s more of the human body. Immune response to vaccines.”
Scroll through the table below to find out which manufacturer’s vaccine is being taken, whether one or two doses are used, and what are the common side effects based on age group. Generally speaking, the elderly have fewer side effects than young people, because our immune response will gradually weaken with age. For two-shot vaccines, such as Pfizer and Moderna’s vaccines, the second injection will amplify the existing immune response, so people usually feel more tired after the vaccine.
The vaccine stimulates our body to produce antibodies to the coronavirus. However, because our immune system cannot distinguish between a real infection and a response caused by a vaccine, they still release inflammatory chemicals to protect us. This is why people get fever, muscle pain, fatigue or headache shortly after shooting.
Johnson’s lens has the least side effects
On the whole, Johnson’s shots are milder and have fewer side effects than the other two. Some experts suspect this is because it is an attempt.
In the Johnson & Johnson trial, nearly 62% of participants younger than 59 experienced side effects, while 45% of people 60 and older experienced side effects.
This is relatively similar to the reported side effects after a dose of Moderna vaccine: about 65% of young people under the age of 65 in the trial had side effects, while 48% of people over 48 years old had side effects. However, after taking the Moderna vaccine for the second time, nearly 82% of the young group had 30% of people who had side effects, while nearly 72% of the elderly had side effects.
But Johnson & Johnson’s injection vaccines seem to be generally not very effective: clinical trials have shown that the vaccine is 66% effective in preventing COVID-19. Both Pfizer and Moderna vaccines are more than 90% effective. However, it is difficult to compare the trials of the two companies at the same time because they occurred at different stages of the pandemic and in different geographic regions.
Common side effects include fatigue and headache
Once the vaccine enters your arm, your blood flow will increase and immune cells will rush to the scene. This may cause pain, redness or swelling at the injection site.
Reactions after Pfizer and Moderna vaccines are more common than those after Johnson & Johnson vaccines. In all age groups, less than 50% of subjects in Johnson & Johnson’s clinical trials reported pain at the injection site, compared with 92% of Moderna subjects and Pfizer’s subjects. Is 84%.
In all trials, headaches and fatigue were also relatively common. Approximately 69% of Moderna participants reported headaches, compared with 55% of Pfizer participants and 39% of Johnson & Johnson.
In the Pfizer and Moderna trials, approximately 63% of participants reported fatigue. In the Johnson & Johnson trial, only 38% of participants reported fatigue, but the prevalence of these side effects also varies with age.
Young people see more side effects, with a few exceptions
Among older participants, only a few side effects appeared to be the same or more than those of younger participants.
After taking two Pfizer vaccines, the combination of the two groups is also common, with about 22% to 23% of people reporting this effect. However, after two injections of Moderna vaccine, adults aged 66 years and older (47%) have more common body or muscle soreness than young people (6%).
Although the elderly generally tend to have fewer side effects, experts say there is no reason to believe that the vaccine will not work well in the elderly.
Cherian said: “For the COVID-19 vaccine, as we age, we actually don’t see a decline in effectiveness, so this is actually a good thing.”
Young people don’t have to worry too much about feeling strong side effects.
Cherian said: “Compared with some side effects of diarrhea or certain muscle soreness, some serious, potentially life-threatening side effects of COVID-19 infection are much better.”