When it comes to the double dose provided by the two-dose COVID-19 vaccines, it is the second dose that really hits.
Kristen Choi can attest to that. Choi, a UCLA nursing researcher, ended a series of symptoms, including a fever that peaked at 40.9 degrees after she received her second injection last year. But the effects passed quickly – and the much-needed protection against the pandemic was well worth it, she said.
“I am very grateful to have received the vaccine and to be able to have this protection, and I really want to see this opportunity available to everyone,” said Choi.
As more Americans line up for the COVID-19 vaccine, some are concerned about the side effects of the second dose, which tend to be stronger than the first. But experts say the symptoms, which range from a sore arm to headaches and nausea, are a sign that the second dose is doing its job: boosting the immune system’s response to the initial dose, thus providing more vigor and longevity. duration. lasting protection against the virus.
Two of the three vaccines authorized for use in the United States – one from Pfizer and BioNTech and the other from Moderna – require two doses, with an interval of three and four weeks, respectively. (The Johnson & Johnson vaccine is a unique business.)
There is no special secret for the second dose: the first and second doses are exactly the same. The first simply prepares the immune system so that it is ready to launch a more robust response when it comes time to roll up its sleeves again.
“It’s just an amplification, basically, of the same process that happens the first time,” said Dr. Diane Griffin, an infectious disease specialist at the Johns Hopkins Bloomberg School of Public Health.
Common side effects include pain, redness and swelling in the arm receiving the injection, according to the Centers for Disease Control and Prevention. Typical side effects in other parts of the body include tiredness, headache, muscle pain, chills, fever and nausea.
And if you don’t experience side effects, “that’s okay,” said Grace Lee, a specialist in pediatric infectious diseases at Stanford Children’s Health. Your body is still doing its job.
“The good thing is that not everyone gets a reaction,” said Lee.
The Pfizer and Moderna vaccines work by giving the body’s cells a design to replicate the virus’s spike protein. Before an immune cell responds to the offensive replica by destroying it, the defender develops a memory of the protein so that it can attack again in the future.
“The fever, headache, etc., that you experience is due to the inflammatory proteins that do their job in the body to get rid of what it believes to be a stranger,” Dr. Jasmine Marcelin, an infectious disease specialist at the University of Nebraska Medical Center, explained in an email.
Choi experienced this first hand. She volunteered for a clinical trial testing the Pfizer-BioNTech vaccine and received her first injection in August. There were practically no side effects – just a sore arm.
But after the second dose of Choi, his arm quickly started to hurt a lot more at the injection site. At the end of the day, she was suffering from chills, nausea and a terrible headache. Around midnight, she woke up with an arm so sore that she could barely lift it. At 5:30 am, she had a frighteningly high fever.
She took Tylenol and drank water. Her fever hovered around 99.5 degrees for the rest of the day. By the next morning, her symptoms had disappeared (except for a sore and swollen lump at the point of injection).
Choi described his experiences in an essay published in December in JAMA Internal Medicine. Since then, she has said she has received emails from hundreds of people, many of whom said they came across her account and said it was comforting to know that these reactions were common, and okay. (Choi learned after the publication that she had actually received the vaccine and not a placebo.)
To be clear, it is rare to have symptoms as intense as the ones Choi experienced: only 4 of a subset of 8,183 participants in the larger clinical study had a fever above 104 degrees (and two of them were in the placebo group), according to published data. in the New England Journal of Medicine and posted on the CDC website.
In fact, in addition to the pain in the arm, the most common side effects after the second dose were fatigue and headache.
Although there have been some cases of severe allergic reactions with the Pfizer-BioNTech and Moderna vaccines, they are extremely rare. For safety, the CDC recommends that people be monitored for 15 to 30 minutes after receiving the injection, so that they can receive immediate treatment, if necessary. Anyone who experiences symptoms such as swelling in the throat, itching, hives or difficulty breathing after leaving the vaccination site should seek emergency medical attention immediately, experts said.
Those who have an “immediate allergic reaction” to a first dose of the Moderna vaccine or the Pfizer-BioNTech vaccine should not receive a second dose, says the CDC. But for everyone else, the experts agree: get the second chance.
Compared to the suffering due to a real fight with COVID-19 – not to mention the possibility of dealing with long-term complications of the disease – there is really no challenge, said Lee, the specialist in pediatric infectious diseases.
“Vaccines are a much safer way to develop immunity,” she said.
And if you’ve never been infected with this coronavirus, you need that second dose of the vaccine to ensure that your immune system’s response is strong and will last over time, experts say.
Choi noted that people aged 55 and under seem to suffer more from the side effects than the elderly. There is a reason for that, she said: “If you are younger, your body has a stronger immune system and a little more capacity to mount that immune response.”
Therefore, as more vaccine becomes available and younger people prepare to get vaccines, it is important that they know what to expect and that side effects are a completely normal part of the process.
“It is a sign that the vaccine is working,” she said.