We have been asked many questions about vaccines over the years and we wanted to share some of them with you, in case you or a loved one might have similar inquiries. Given that each person’s situation is unique, the answers here are intended to provide general information and guidelines.
Please feel free to call or drop by to talk with one of our knowledgeable pharmacists about your specific situation. We are more than happy to discuss your circumstances with you.
Q&A about Influenza and COVID vaccines
What is the best time to get a flu vaccine? What if I have just had the flu? How effective is it?
If you have just been sick from COVID, you may wait up to 4 months after the end of your infection before getting the updated COVID vaccine. You may be vaccinated sooner if you choose. Just make sure you are fever free with significant symptom improvement before being vaccinated. If you recently received last year’s vaccine, you should wait a minimum of two months after receiving the Pfizer vaccine or three months after receiving Moderna’s mNexSpike before receiving this year’s vaccine.
Influenza is caused by a virus that affects our respiratory system. The flu virus mutates and changes over time, which is why an updated flu vaccine is developed every year to match the strains anticipated for the upcoming flu season. Getting a flu vaccine annually also helps because the level of flu antibodies that our system produces (as a response to the vaccine or to getting the illness) may diminish over time. Finally, an annual flu vaccine is protective because our antibodies from the previous year might not be as effective for upcoming strains.
Depending on your age, vaccine method preference, and/or health condition, you may have choices for the type of flu vaccine you get. Drop by, call us, or check out the vaccines page of our website for more information:
What is the best time to get a COVID vaccine? What if I have just had COVID? How effective is it?
If you have just been sick from COVID, you should wait 4 to 6 months after the end of your infection before getting the updated COVID vaccine. People who have had a COVID vaccine recently should wait at least 6 months before getting this season’s version.
If you take medications or have medical conditions that can be affected by the COVID vaccine (or vice versa), please feel free to discuss with one of our pharmacists.
The bottom line is that COVID vaccines continue to be effective. They are associated with lower risk of critical COVID-19 illness (intensive care unit “ICU” admission or death).
General Q&A
Here is a general explanation of how vaccines work. More Q&A follow afterwards because understanding the mechanism helps with understanding the answers to the questions.
Vaccines work by triggering an immune response by our bodies without our having to get sick with the illness. Getting vaccinated means introducing an element into our bodies that makes us produce antibodies to fight the specific illness or pathogen (disease-causing organism).
Traditional vaccines work by introducing weakened or reconstituted, non-dangerous fragments or versions of the pathogen into our body. mRNA vaccines contain the blueprint that tells the body to produce the specific antibodies. (Read more about how mRNA vaccines work in a previous blog we wrote, here: https://thepharmacyatwellington.com/not-all-vaccines-are-created-equal/) Our body reacts to the fragments or the blueprint by producing antibodies.
It takes approximately two weeks for a vaccine to become fully effective. After that, if we are exposed to that illness, the new antibodies we have circulating can help fight the illness and keep us healthy.
Why do some vaccines require multiple doses?
Sometimes our bodies need a repeat reminder, spread out over weeks, months, or years, for how to fight off certain infections.
Also, sometimes the amount of antibodies we have against a particular illness becomes reduced over time and a second trigger to produce sufficient antibodies is needed.
Some vaccines are needed on an annual basis because the pathogen mutates and we need an updated vaccine to fight the latest strain(s).
Why aren’t vaccines 100% effective?
Many factors can affect vaccine efficacy and they can vary from person to person:
- age, health conditions, medications
- strength of immune system
- exposure to the pathogen
- pathogen changing over time
- etc.
Why are there so many vaccines?
Each vaccine is developed to fight against a specific illness, and there are quite a few illnesses that are dangerous to humans in circulation. Having said that, certain vaccines are combination ones, for example, Measles-Mumps-Rubella (MMR).
Are vaccines safe? Do they cause autism, HIV, diabetes, or cancer?
Vaccines are safe and do not cause autism, HIV, diabetes, or cancer. All vaccines undergo careful and thorough testing and assessment, including laboratory testing, and clinical trials bound by strict regulations at each of three phases. These procedures are established to evaluate the safety of a vaccine candidate and how well it prevents the disease it targets. Regulators monitor the trials, review results, and decide whether to approve the vaccine or not.
Even after a vaccine is approved, it continues to be subject to continued monitoring over a longer timeframe.
We might hear about certain personal experiences with vaccines from friends, family, and/or acquaintances and it would be prudent to keep in mind that while their experiences are valid, it is relevant to rely on results of studies and clinical trials performed on more than a handful of people. In other words, a sufficient sample size will provide more accurate and reliable results and recommendations.
Image credit: Liza Summer on Pexels
Is it better to rely on natural immunity, rather than being immunized using a vaccine? Can I just ensure that I have good hygiene and nutrition rather than having to get vaccines? Should my child get chickenpox/measles at a chickenpox/measles party? That would provide exposure to my child’s immune system so that it can produce antibodies.
Being immunized using a vaccine gives your body the chance to put up an immune response so that it is ready before you are exposed to a particular illness. Thus, when the illness comes along, your body has a higher chance of being able to fight it off.
Where a person relies on fighting off the illness the very first time their body encounters it, it is possible to overcome the illness, but since the immune system hasn’t encountered the pathogen before, it takes a bit of time to produce the necessary specific antibodies. Sometimes the immune response isn’t strong enough or it doesn’t happen quickly enough, or other reasons can prevent it from being able to overcome the illness. Again, vaccines are developed to help prevent people from catching illnesses that can have serious medical consequences.
While chickenpox can cause just mild symptoms in kids, it is also possible for the symptoms to be quite serious. Once a person has had chickenpox, s/he can get shingles later on in life. We know that shingles can come with debilitating pain. (Here’s a link to a blog that we wrote about measles and shingles, which are related: https://thepharmacyatwellington.com/chickenpox-and-shingles/)
Measles, on the other hand, can lead to serious complications, up to death. A person who overcomes measles in childhood can still develop subacute sclerosing panencephalitis (SSPE), a fatal disease of the central nervous system, 7 to 10 years later. Getting the measles vaccine and not exposing a child to a measles party is preferred.
While good hygiene and balanced nutrition help with overall health, they do not cause our immune system to produce specific antibodies to fight specific pathogens.
Getting vaccinated increases the chances of overcoming specific illnesses.
What is herd immunity?
Most people can be vaccinated, but some people have health conditions that do not permit them to be vaccinated. For example, they may have cancer or HIV or other illnesses that weaken the immune system. Or, they may be allergic to a vaccine component.
When a sufficient percentage of the community is vaccinated, the pathogen has a hard time circulating because most of the humans it encounters are immune. This means that the people who cannot be vaccinated end up with less exposure to the pathogen. This is herd immunity.
So, the more that people who can get vaccinated do, the better protection for the whole community.
For the following questions, because they are so specific to individual circumstances, we encourage you to talk with one of our pharmacists:
- If I’m allergic to things such as eggs, how does this affect what vaccines I can get?
- Are there age restrictions for getting vaccines?
- If I get a vaccine during pregnancy, is my baby protected?
- Which vaccines do I need? I don’t remember or know which vaccines I’ve had — do I have to get them again?
- Can I get multiple vaccines at the same time? Will doing so overwhelm my body?
- I am currently sick. Should I wait until I’m 100% again before getting any vaccines at all?
Please feel free to discuss further with any of our caring pharmacists. Each situation is unique and we are available and happy to answer questions.
References and Resources
Mayo Clinic on more vaccine questions – https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-myths/art-20485720
Journal of the American Medical Association (JAMA) on COVID vaccine efficacy 2026-27 – https://jamanetwork.com/journals/jama/fullarticle/2853778
World Health Organization on vaccine safety – https://www.who.int/news-room/questions-and-answers/item/vaccines-and-immunization-vaccine-safety