CLEVELAND, Ohio – Readers have questions regarding the second injection of the COVID-19 vaccine, especially whether people who have recovered should take the second injection, and about allergic reactions and side effects.
We are providing answers from health experts.
If you have specific questions about how a pre-existing condition or pregnancy can affect your ability to get the COVID-19 vaccine, ask your primary care physician. Find out if you can ask questions by email or arrange a telehealth visit to answer your questions.
Q: Should individuals who have recovered from COVID-19 get the vaccine? Do they need both doses?
A: Health experts say it is beneficial and safe for people who have taken COVID-19 to also receive the vaccine.
The protection that comes from recovering COVID-19 is called natural immunity, according to the Centers for Disease Control and Prevention. This is because the body has created antibodies against the coronavirus, and these antibodies help protect against subsequent infections.
The vast majority of people infected with COVID-19 produce at least some antibodies. The vaccine will increase the natural immune response that already exists after recovery from the disease, health experts say.
The immune response to natural infection has a variety, while the vaccine produces a measurable and predictable immune response. This is another reason why people with natural immunity should still be immunized.
Here is an explanation of why both doses of the Moderna or Pfizer vaccines are important.
People with COVID-19 antibodies may have a low risk of being reinfected, suggests a new study by the National Cancer Institute.
Single vaccine for survivors?
A new study suggests that those who have had COVID-19 may need only one injection of the vaccine to protect against future infections. The Pfizer and Moderna vaccines require two injections, given a few weeks apart.
The study, published in January, found that coronavirus survivors had much higher levels of antibodies after receiving two doses of the vaccine, compared with those who did not contract COVID-19. The study also found that people who already had coronavirus were more likely to experience side effects, including headaches, muscle pain and chills, after receiving the first vaccine.
A new study suggests that an injection of the Pfizer vaccine provides significant protection after a dose.
Q: How long after recovery can people who took COVID-19 receive the vaccine? Should they wait 90 days?
A: The CDC recommends waiting 90 days to receive the COVID-19 vaccine if a person has recovered from a COVID-19 infection and has been treated with monoclonal antibodies or convalescent plasma.
The interactions between these treatment methods and the COVID-19 vaccines have not yet been studied, said the CDC.
People who test positive for the disease, showing only mild symptoms and without treatment for the coronavirus, should wait until the period of isolation recommended by the doctor ends before receiving the vaccine.
P: If you took the first dose of the vaccine without any allergic reaction, can you have an allergic reaction with the second dose?
A: There is a difference between an allergic reaction and side effects. A severe allergic reaction requires treatment with epinephrine or hospitalization, according to the CDC.
Some people experience immediate, non-serious allergic reactions, such as wheezing, hives and swelling, four hours after vaccination.
People who experience a severe or non-severe allergic reaction with the first dose of the vaccine should not take the second injection, according to the CDC.
A CDC study published in January showed that between 14 and 23 December 2020, there were 21 cases of anaphylaxis after the administration of 1,893,360 first doses of the Pfizer-BioNTech COVID-19 vaccine (11.1 cases per million doses) . Of these cases, 71% of them occurred within 15 minutes after vaccination.
This Cleveland Clinic article gives more details on vaccines and allergic reactions.
If you get one red, itchy, swollen or painful rash on the arm where you received the injection, you have “COVID arm”. If the first injection causes a skin rash, you should still give the second injection at the recommended time, recommends the CDC. Try to hit the second shot on the opposite arm.
Here is a story discussing why the “COVID arm” is not dangerous and why people who receive it must receive the second dose of the vaccine.
Side effects vs. allergic reactions
The side effects of vaccines – pain at the injection site, fatigue, muscle pain, joint pain, headache and redness at the injection site – are expected in people who have had and have not received COVID-19.
The clinic’s website addresses the side effects of the vaccine and whether the side effects are worse if a person has recovered from COVID-19.
P: Does the lack of a significant reaction with the second dose of the vaccine indicate that the vaccine is less effective?
A: Many people experience mild side effects, such as pain at the injection site and low fever, after receiving the vaccine. But the lack of side effects is not an indication that the vaccine is not working for you
Q: Should I have a PCR or antigen test to determine if the vaccine was effective?
A: The CDC does not promote antibody testing to find out who has immunity after receiving the COVID-19 vaccine. Commercial antibody tests may not screen for the same antibodies that the vaccine produces. Someone who has been immunized and is immune to the virus may still have negative results for certain antibodies, health experts said.
In clinical trials, the Pfizer-BioNTech and Moderna vaccines protected against the coronavirus 95% of the time and 94% of the time, respectively. But that does not mean that all vaccinees will be tested positive for antibodies, health experts said.
Here’s another story discussing why you shouldn’t have a COVID-19 antibody test after vaccination.
Answers to your questions about the coronavirus vaccine:
How will local pharmacies keep the coronavirus vaccine in place if it needs to cool? How will they avoid waste?
If Pfizer and Moderna vaccines are for people aged 16 and over, what does this mean for children? What about minors with pre-existing illnesses?
Should cancer patients receive the coronavirus vaccine?
Can you order a coronavirus vaccine if you have questions about the other?
Should you get the coronavirus vaccine if you have had a negative reaction to the flu vaccine?
Are you contagious if you have side effects from the COVID-19 vaccine?
Can you mix and match two doses of coronavirus vaccine from different manufacturers?
Can I still get my second dose of coronavirus vaccine if I develop COVID-19 symptoms after the first one?
Should you get the second vaccine if you get COVID-19 after the first dose of the coronavirus vaccine?
Will your COVID-19 vaccine be less effective if you need to wait longer for the second dose?
If the coronavirus vaccine is 95% effective, how will you know if it is in the other 5%?
Why do I need to keep a mask on if I have been vaccinated against the coronavirus?