With your first dose of Pfizer or Moderna vaccine, you probably felt a mild sore hand.
But the second dose is gaining a reputation for packing punches. About 40 to 50 percent of people experience symptoms such as fatigue, headaches, and a cold or fever.
As millions of Californians wait for their shots, they wonder: What’s going on? We asked the experts.
Q: Why do we feel the side effects of the vaccine?
a: “The ‘reactogenicity’ we see – local and systemic reactions – is short-lived and usually occurs between one and three days after vaccination. It is essentially a reflection of the way your body develops immunity. “
Ce Grace Lee, MD, Professor of Pediatrics at Stanford University School of Medicine
Q: Why do more problems occur than the second dose?
a: The first shot teaches your immune cells to identify the virus; It’s over again. With the second shot, there are more immune cells ready and waiting for any major defense to begin. Muscle pain and fever come from inflammation; Your immune cells are sending alarms in the form of chemicals called cytokines.
“Your immune system is ‘prime’ with dose. You’re getting ‘boosted’ with dose two. It reflects your body’s rapid response. Your body is seeing it a second time and remembering it, and it is developing a powerful immune response that is needed to respond to the infection. ”
Ce Grace Lee, MD, Professor of Pediatrics at Stanford University School of Medicine
Q. What can I do to cope with the side effects?
a. Don’t be tempted to skip your second dose. Pfizer-Bioentech shots are 21 days apart; Moderna shots are 28 days apart. While the first dose provides little protection around 12 days, you will not be completely safe for the next two weeks after your second dose.
If possible, schedule another dose when you can get a little more rest. If you experience severe side effects, it is safe to take acetaminophen (Tylenol) or ibuprofen (Advil). Ice can help sore hands. Severe allergic reactions are very rare.
Q: Is there an age difference in response?
a: Older adults have a milder response than younger people because “their immune system doesn’t react as strongly as a young person’s, but they still have 95 percent protection from the virus.”
િયમ William Schaffner, MD, Professor of Preventive Medicine and Infectious Diseases at the University of W વrttemberg School of Medicine
Q: Why doesn’t everyone experience them?
a: Aside from age, experts do not know why some people have more severe reactions than others.
“Everyone responds differently. There really are a series of side effects or reactions and not everyone will have much. And that’s exactly because we have trial data that doesn’t have side effects, but it has a lot of effectiveness. “
Ce Grace Lee, MD, Professor of Pediatrics at Stanford University School of Medicine
Q: I felt fine after the second dose. Does that mean I’m not safe?
a: Think back to your education. You may have fond memories of elementary school. Ledge to high school or college was difficult. It doesn’t matter.
“Elementary vaccination was a simple material to teach the immune system, just like primary school. Sixth standard fractions and all that – it’s very simple, but important.
Does that mean that elementary school education was not really education, because it doesn’t really hurt you? No.
And then there was secondary school or college college education, which is a little tough. He entered into calculus and physics. But still, the immune system went through it, and it was really great.
In the end, you got a full education. That’s how vaccines work. “
Ali Bali Pulendran, MD, Professor of Microbiology and Immunology at Stanford University School of Medicine.
Q: Why other vaccines do not cause these problems?
a: Some do.
“It happens with many, many other vaccines. With the Shingrix Shingles vaccine, people sometimes say: ‘Oh my God, that’s another shot. I had a fever one day. ‘
“This is not something that is specific to the mRNA vaccine. This is a common feature of any vaccine. ”
Ali Bali Pulendran, MD, Professor of Microbiology and Immunology at Stanford University School of Medicine.
Q: If I am exposed to the virus after vaccination, will I also experience these symptoms?
a: Impossible.
“It depends on how many viruses enter your system. If you come in contact, it will penetrate your nasal passages – and hopefully, it will stay there. Which we call ‘mucosal immunity’. It is a local immune response.
“It’s not like a second dose of vaccine, which is injected into your entire system, and so the lymph nodes respond. This is the response of the whole body. ”
ણા Aruna Subramaniam, MD, Clinical Professor of Medicine – Infectious Diseases at Stanford Healthcare
Q: What are “vaccine failures”?
a: “We are learning that both of these vaccines seem to work very well to prevent serious disease and hospitalization. But in clinical trials, some people have developed symptomatic disease. And that’s a sign that the vaccine isn’t working and that’s what we’re looking for. We would all like for her to prevent the disease. ”
C. Anne Lutkemeyer, MD, Professor of Infectious Diseases at UC San Francisco
Q: Is there a chance that I will get infected after getting the vaccine, but do not experience any symptoms?
a: “My guess is that we’ll find out about asymptomatic infections – if and when they occur after vaccination – that there are a few viruses around people.
“It really won’t be enough to set up a strong infection or inflammatory response. I suspect we won’t see ‘long walk’ complications. Is it contagious to others? It remains to be seen. ”
CS Anne Luetchemeyer, MD, Professor of Infectious Diseases at UCSF
Q: How long does the vaccine protect after the second dose?
a: We don’t know yet.
“The data is incomplete because we haven’t had these vaccines for a long time. But the good news is – at the time we got them and were able to study them – we didn’t really see a significant drop in the level of immunity.
“Right now it seems that the ‘half-life’ of antibodies after vaccination is at least a year, and probably longer than that.”
El Joel Ernst, MD, Professor of Medicine and Chief of the Division Exper f Experimental Medicine at UCSF
Q: Is it possible that we need ongoing “booster shots”?
a: If needed, the vaccine “booster” can help in two ways. They can recharge the immune response against the original virus. They can also help prevent new viral variants that may render existing vaccines ineffective. But it could not be ascertained if they were necessary.
“What we don’t know is exactly what level of antibodies is enough to protect us. So there’s a lot of monitoring right now, and an increasing amount of viral sequencing to find out what types are emerging. “
El Joel Ernst, MD, Professor of Medicine and Chief of the Division Exper f Experimental Medicine at UCSF
