Some of the tens of thousands of patients who took shots of the new COVID-19 vaccines from Pfizer and Moderna during Phase 3 clinical trials reported occasional unpleasant side effects.
“I woke up around midnight freezing,” said Jocelyn Edwards, 68, a retired nurse who tested the Moderna vaccine, according to The Wall Street Journal. “For the next 24 hours I had intense chills, serious neck pain, headache, all my joints were aching.”
Edwards also had a fever that eventually peaked at 102.4 degrees. She sweat so much she lost three pounds, she said. But the next day after her second shot, she felt fine when she woke up.
A trial researcher told Edwards that she had exactly the right response, with her body quickly building a strong immune response. “It’s better having 36 hours of feeling really rough than getting Covid,” Edwards said.
“It’s a really good sign that there is a signal from your body that there is something different inside you,” Paul Duprex, director of the Center for Vaccine Research at the University of Pittsburgh, told the paper. “It’s being recognized by your immune system to make all important SARS-CoV-2 antibodies.”
Three vaccines are currently in the works. Pfizer’s last week was approved for emergency use authorization (EUA) by the Food and Drug Administration (FDA). That vaccine is already being distributed and put into use. On Thursday, the FDA will consider Moderna’s EUA request. Moderna said its data showed their vaccine was 94.1% effective in its late-stage clinical trial, just under Pfizer’s efficacy rate of 95%. The Moderna vaccine was developed in conjunction with the Trump administration’s Operation Warp Speed.
A key advantage of Moderna’s vaccine is that it does not need sub-zero storage like Pfizer’s, which needs to be stored at -94 degrees Fahrenheit.
A third vaccine is also in the pipeline. AstraZeneca and Oxford University on Nov. 23 said their jointly created COVID-19 vaccine has proven to be up to 90% effective and the makers claims will be easier to distribute.
Said the Journal: “Pfizer’s vaccine, which uses technology similar to Moderna’s, showed similar side effects, according to data released last week. Among its volunteers aged 18 to 55 receiving their second dose, 15.8% got a fever, compared with 0.5% of the placebo group; 35% got chills versus 4% of placebo recipients; and they also got more headaches and were more fatigued than those who got the placebo. Volunteers in both trials who received the vaccine also reported pain at the injection site more frequently than placebo recipients.”
The Centers for Disease Control and Prevention (CDC) on Monday told Americans what to expect when they take the vaccine.
“You may have some side effects, which are normal signs that your body is building protection. These side effects may affect your ability to do daily activities, but they should go away in a few days,” the CDC said.
The agency said you’ll experience some pain and swelling on the arm and that you’ll also get a fever, chills, headache and fatigue. “Side effects may feel like flu and even affect your ability to do daily activities, but they should go away in a few days,” the CDC said. “In most cases, discomfort from fever or pain is normal.”
But the agency said to contact your doctor or healthcare provider “if the redness or tenderness where you got the shot increases after 24 hours” or “if your side effects are worrying you or do not seem to be going away after a few days.”
The CDC also urged vaccine-takers to get the second required shot, even if they had side effects from the first.
“With most COVID-19 vaccines, you will need 2 shots in order for them to work. Get the second shot even if you have side effects after the first shot, unless a vaccination provider or your doctor tells you not to get a second shot.” The CDC added: “It takes time for your body to build protection after any vaccination. COVID-19 vaccines that require 2 shots may not protect you until a week or two after your second shot.”