An influenza-like illness is a likely side effect of being inoculated against Covid-19, the World Health Organization's global advisory committee on vaccine safety said in a statement on Monday.
The committee said that the benefit-risk balance of Covid-19 vaccines "remains favorable" after it reviewed the data for influenza-like illness among health-care workers who had received the jab.
Its review, conducted virtually on February 25, found that the vaccines may induce flu-like symptoms, including headache, fatigue, muscle aches, feverishness and chills.
The side-effects were reported during the first few days after inoculation in clinical trials in several countries.
"Most symptoms were mild to moderate and resolved within a few days," the statement said, adding that side effects were more common among the under-55s.
The committee concluded that its safety advice for the vaccines could remain unchanged, because the side-effect reports are consistent with what would be expected.
It advised that people who suffer headache, fever or muscle aches after their first dose should still get their follow-up booster jab as planned, and that people should be made aware of the potential side effects prior to vaccination.
Its review, conducted virtually on February 25, found that the vaccines may induce flu-like symptoms, including headache, fatigue, muscle aches, feverishness and chills.
The side-effects were reported during the first few days after inoculation in clinical trials in several countries.
"Most symptoms were mild to moderate and resolved within a few days," the statement said, adding that side effects were more common among the under-55s.
The committee concluded that its safety advice for the vaccines could remain unchanged, because the side-effect reports are consistent with what would be expected.
It advised that people who suffer headache, fever or muscle aches after their first dose should still get their follow-up booster jab as planned, and that people should be made aware of the potential side effects prior to vaccination.