How Do the Vaccines Work?
This Page’s Contents
What is a Vaccine?
Quick Summary: Vaccines help your body fight off certain kinds of diseases so that you’re less likely to get sick from them, and if you do get sick, it’s probably not going to be as bad.
Vaccines are shots that can help prepare your body to fight off different kinds of infections, including from viruses like the one that causes COVID-19. Most viral vaccines work by exposing your body to a harmless part of the virus so your immune system can learn to recognize and fight it without you actually having to get seriously sick. Check out this video for a fun visualization! When you feel sick or sore after getting a vaccine, it’s because your body is preparing for future fights. We have vaccines for many different kinds of bugs, including smallpox, measles, the flu, and now COVID-19.
Thanks to vaccines, we have prevented millions of deaths and helped millions of people live healthier lives. In fact, it was thanks to vaccines that we eradicated polio and smallpox!
What are mRNA Vaccines? (Pfizer and Moderna)
Quick Summary: Pfizer and Moderna vaccines use a harmless bit of material called mRNA to teach your body about COVID-19, but they don’t change your DNA, and you can’t get COVID-19 from the vaccine.
Vaccines can be created in a number of ways, with the end goal being to teach your body how to identify the bug and fight it if you ever come in contact with it. One way to do this is through an mRNA vaccine, like the Pfizer and Moderna COVID-19 vaccines. These types of vaccines use a kind of genetic material called “mRNA” that can be used to identify the virus, and provide a copy of it to the parts of your body that fight infections, called immune cells. These cells will make a record of the important parts of the mRNA, and if they ever come in contact with it again, they will already know that it's something they need to fight before it can seriously infect you.
Though mRNA is a type of genetic material, it doesn’t change your DNA at all, and isn’t the actual virus (but is a way to identify the virus). You can check out this TikTok we linked earlier to get an idea of how this works! To say it another way—the COVID-19 vaccine cannot give you COVID-19 and doesn’t change your genetics.
The most common side effects of the vaccine are pain, redness, and swelling where you get the shot. You may also feel tired, have a headache, muscle aches, chills, fever, or feel nauseous. Allergic reactions to the vaccine are very rare and are typically caught and treated immediately, and those who have an allergic reaction to one COVID-19 vaccine can get their future doses using one of the other vaccines.
What are Viral Vector Vaccines? (Johnson & Johnson)
Quick Summary: The Johnson & Johnson vaccine uses a harmless virus that looks a bit like COVID-19 (but isn’t COVID-19!) to teach your body about COVID-19, but it doesn’t change your DNA, and you can’t get COVID-19 from it.
Another way to create vaccines is by using a viral vector, which is a modified and harmless version of a virus that can’t infect you. The harmless virus has a little part on it that looks like a part that’s on the real COVID-19 virus so your body learns what to look for and is ready to fight the real thing. It is not the same virus as the one you are getting the vaccine against. In fact, the Johnson & Johnson vaccine uses a harmless virus, but not the COVID-19 virus, to teach your body how to fight against COVID-19. Like mRNA vaccines, viral vector vaccines don’t change your DNA at all, and you can’t get COVID-19 from them.
Vaccine Side Effects
Quick Summary: The vaccines can make you feel a bit sick for a day or two, but that’s not COVID-19—that’s just the process of your body getting ready to fight COVID-19 in the future.
Because your body will be building an immune response to the vaccine, you might experience some symptoms that make you feel sick. Some people don’t experience any symptoms, and others have symptoms that last a few days and can make them feel quite crummy! Although you might feel sick, you don’t actually have COVID-19 and aren’t having side effects of COVID-19. You’re just having side effects of your body building up immunity to it. Better to feel sick for a day or two now than spend weeks feeling much much worse. Think of it like practicing for a marathon. You go on several runs that can be quite hard at first until you build up your endurance. Then, when you run the marathon itself, it’s much more doable because you’ve prepared!
Do the Vaccines Interfere with GAHT/HRT?
Quick Summary: COVID-19 vaccines don’t interfere with GAHT/HRT.
The COVID-19 vaccine does not interfere or interact with Gender-Affirming Hormone Therapy (GAHT)/Hormone Replacement Therapy (HRT)—either with estrogen, testosterone, spironolactone, or other medications part of an GAHT/HRT regimen. GAHT/HRT is used by many trans and nonbinary folx who are medically transitioning, as well as some people with other conditions. So, it’s safe to get vaccinated if you’re on GAHT/HRT!
Do the Vaccines Work for People Who are Immunocompromised?
Quick Summary: Yes, they should work for most people who are immunocompromised, but an additional dose is needed.
The COVID-19 vaccines should provide protection for most people who are moderately or severely immunocompromised, including people with advanced or untreated HIV, but an additional dose is needed. While some people who are immunocompromised may not get as much protection from the vaccines as people who aren’t immunocompromised, the increased risk COVID-19 poses to people with a compromised immune system makes getting the vaccine even more important.
Do the Vaccines Interfere with PrEP or HIV Treatments?
Quick Summary: COVID-19 vaccines don’t interfere with PrEP or HIV treatments.
If you are living with HIV, you are strongly urged to get the COVID-19 vaccine because you are at increased risk of infection in general. The COVID-19 vaccine does not interfere or interact with HIV or PrEP medications, so you should not stop or change your HIV medications to get the vaccine. If you're on PrEP, you should know that it only protects you against one virus: HIV. You might have heard that Truvada, which is made up of drugs that fight HIV, helps against COVID-19 because HIV and COVID-19 are both retroviruses, but that’s not true. The vaccine is currently the best medical treatment to prevent COVID-19 infections. So, if you are interested in being protected against COVID-19, you should get the vaccine!
If you have HIV and have been treating it, you’ve already been working so hard to take care of yourself and your loved ones by taking those medications—getting this vaccine is simply another step in doing that work!
What About COVID-19 Variants Like Omicron?
Quick Summary: The COVID-19 vaccines do work against the omicron variant and should also work against other new variants that emerge.
The COVID-19 vaccines are effective and safe at preventing severe disease and death from all known types of COVID-19, including from the omicron variant and subvariants like BA.2, but a booster shot is needed for maximum protection.
Why Do We Need Booster Shots?
Quick Summary: A booster is needed to make the COVID-19 vaccine more effective against variants, and because the protection from vaccines doesn’t last forever, we need booster shots to keep it working.
We need boosters for two reasons: First, because some vaccines don’t work forever—the immunity can fade over time, so getting a booster keeps you protected. Second, boosters increase the effectiveness of the vaccine against variants like omicron.
How Long Does it Take the Vaccine to Work?
Quick Summary: It takes about two weeks for the vaccines to work after you get vaccinated.
If you get a vaccine that requires two shots (Moderna or Pfizer), you are considered fully vaccinated two weeks after your second shot (or third shot if you’re immunocompromised), but you’ll need a booster shot to have maximum protection against variants like omicron.
If you receive a vaccine that requires one shot (Johnson & Johnson) you are considered fully vaccinated two weeks after that shot (or after your follow-up shot of Pfizer or Moderna if you’re immunocompromised), but you’ll need a booster shot to have maximum protection against variants like omicron.
This is very similar to other vaccines we have, like the flu shot. Your body needs time to react to it and build up your immune system. You’re not protected immediately, but you will be two weeks after being fully vaccinated. So, if you’re social distancing, masking, and isolating because you are unvaccinated, you’ll want to continue that during the two-week period following your vaccination. Of course, you’ll want to keep yourself safe in these ways even after you’re vaccinated, until the spread of COVID-19 is reduced and we learn more about the variants.
We Got Vaccinated!
Quick Summary: We all got vaccinated, and we’re doing fine. We even posted online about our personal experiences getting vaccinated.
All of us at Queering Medicine have already gotten the vaccine, and now we’re getting boosters! If you want to know what it was like for us, take a look at our QM Vaccine Experiences page to read what QM members experienced. Spoiler alert: not much happened beyond some soreness! In fact, that’s really what you can expect in terms of side effects from the vaccines in the United States. Many of the side effects that have been reported—pain, redness, and swelling at the injection site—are common in vaccinations, as are other minor side effects such as fever and headache for a day or two. These side effects are regular ways that our body’s immune system responds when introduced to something unfamiliar. So that’s often one way you know the vaccine is working!
What’s in the Vaccines and Boosters?
Quick Summary: The COVID-19 vaccines don’t have anything harmful in them and do not contain any metal, magnets, mercury, microchips, stem cells, or egg products.
During the pandemic there has been an issue with the spread of misinformation regarding the COVID-19 vaccine. Vaccines, including mRNA vaccines, do not rewrite our DNA. They do not have the components needed to do that, and there is never any contact between the contents of the vaccine and our own DNA. There are also no metals, magnets, microchips, mercury, stem cells, or egg products in the vaccine. Really, what’s in them is standard for any vaccine:
The Pfizer and Moderna vaccines are made of mostly the same things:
mRNA, which is the part that your body will learn from to fight off COVID-19; it cannot infect you in any way.
Special fats (also called lipids) to help your body interact with the mRNA.
Both vaccines also contain salts and sugar, and the Moderna contains additional acids to keep the other parts of the vaccine fresh while it’s being shipped to you (so that it still works when you get it!).
Think of the vaccine ingredients like shipping a crystal vase: The mRNA is the fragile contents, the lipids are the bubble wrap, and the salts/sugars are the packing tape. Basically, everything is designed to help the vase get delivered without breaking!
The Johnson & Johnson vaccine is made of two parts:
Harmless bits of a virus, which is not COVID-19 but is made to look like it to your immune system; your body will learn from this virus to fight off COVID-19, but it cannot infect you in any way.
Salts, sugars, and acids to keep the other parts of the vaccine fresh while it is being shipped to you (so that it still works when you get it!).
When it comes to boosters, the overall ingredients are the same, just different amounts.
If you want to read the detailed list of the ingredients, you can read them here: Pfizer ingredients, Moderna ingredients, and Johnson & Johnson ingredients.