by Samantha McKinnon, PharmD Candidate 2019
University of Arizona College of Pharmacy
With flu season right around the corner, what better time to talk about vaccines than right now? We talk and hear about vaccines a lot, but what exactly is a vaccine, and which vaccine is right for you?
What is a vaccine?
In the simplest terms, a vaccine is medicine created from weakened or dead disease-causing germs given to you to help prevent you from getting sick or prepare your body in case you are infected.1 Vaccines can be created using different strategies, depending on who the vaccine is intended for and what disease is trying to be prevented. There are live, inactivated, recombinant and toxoid vaccines; each serves a different purpose and treats a different germ.1 The way they work is to expose you to a small and safe amount of the germ so your body will recognize it in the future by creating antibodies. Antibodies are what allow your body to fight off infections or you experience a much milder version of the illness.2 You may sometimes see terminology like “trivalent” or “quadrivalent” when you’re looking at different flu vaccines.3 Trivalent vaccines contain three different strains of virus whereas quadrivalent vaccines contain four different strains of virus. There also “high-dose” flu vaccine formulations, these formulations contain extra amount of virus material to help people create more antibodies.1
Live vaccines are also called sometimes called “attenuated” – which is a fancy term for “weakened”. Some examples of live vaccines you or children may have received would be measles, mumps, rubella (MMR), chickenpox or even smallpox. Live vaccines take the entire virus and weaken it so that it can’t get you as sick as the regular beefed-up virus. Imagine you have two runners getting ready to run a marathon, but one of the runners has 20-pound boots on, who will win the race? It’s going to be much harder for the runner with boots to cross the finish line, this is essentially what attenuating viruses do. Live vaccines do come with some risks, especially to people with weaker immune systems such as someone that had an organ transplant or someone with cancer.
Vaccines that inactivate the virus also use the entire virus but instead of being weakened like a live vaccine, it is completely dead. Inactivated vaccines are the typical flu shots, polio and rabies. Because these germs are completely dead you will not get sick, but this means you will also not be immune and need more frequent shots.3 This is one reason for an annual flu shot.
Recombinant is technical term that basically means mixed up, it would be like switching some letters around in the alphabet to be CBADEFG instead of ABCDEFG, it’s still the alphabet but not in the exact order it used to be. These vaccines use only very specific pieces of the germ, a “target”, which will create a strong response in the person receiving the shot. The bonus is that the vaccine does not have the entire germ, so you won’t get sick and they can be used on more people than live or inactivated vaccines – a big plus for patients with weaker immune systems. Some recombinant vaccines currently used are for Hepatitis B, meningitis, shingles and whooping cough.
What changed for this year?
Now that you know about all the different kinds of vaccines we can talk about the new changes for this year. Besides the World Health Organization (WHO) and the Centers for Disease Control (CDC) there is also another government body called The Advisory Committee on Immunization Practices (ACIP) that provides recommendations for what immunizations are needed and when. Previous flu seasons did not have very good coverage against H1N1 so live viruses were not recommended for children. That has changed this year, ACIP has recommended that eligible patients receive the FluMist intranasal spray, a live attenuated vaccine, this is good news for parents and kids as there is no needle and no shot.4 The recombinant flu shot called Flublok is recommended for pregnant women. For the older population there has been a change to the zoster vaccination recommendation. ACIP recommends the recombinant Shingrix vaccine for prevention of shingles in adults over the age of 50.4 Shingrix is a two-dose vaccine just like the previous shingles vaccination Zostavax but has been found to be more effective than Zostavax, most especially in patients over the age of 80.5 The final changed recommendation is in regard to the live MMR vaccine. Traditionally it has been a two-dose vaccine and that covered you for life. With recent measles outbreaks, patients living in an area with an outbreak are recommended to receive a third dose of MMR.5
What vaccine is right for you?
The CDC releases an immunization schedule for all patient populations and revises it as new evidence comes to light. The recommendations from ACIP have allowed the CDC to release a newly revised immunization schedule effective for 2018. Based on your age and your health you may get different versions of vaccines or vaccinated at different times in your life than other people. Your provider or pharmacist would be happy to let you know which vaccines are right for you and when, since some vaccines are age-specific. It is especially important to let health professionals treating you know your health status and social history such as if you smoke tobacco or drink alcohol, if you’ve recently been sick or had a fever, what kind of environment you work in, if you’ll be around newborns or elderly people, your HIV status or if you have liver problems or blood factor issues as well as any allergies. If you travel outside of the US, especially to an area that requires you to use antivirals, let your prescriber know as this may affect your vaccinations. Some countries also require special immunizations before you may be allowed to enter, be sure to check these recommendations on the CDC website.
The importance of getting vaccinated
Diseases like polio, measles, whooping cough, flu can be prevented with vaccines. Without vaccines people that caught these viruses could be paralyzed, blinded, lose their hearing, or even die. In 2015 there were 710,000 people hospitalized for flu and over 56,000 of them died. There are some patients that can not be vaccinated and depend on others to be vaccinated so they do not get sick. This is called “herd immunity,” the more people that are vaccinated, the healthier everyone will be. So don’t wait, get vaccinated today!
- Felicilda-Reynaldo RF, “Types of flu vaccines for yearly immunization.” MedSurg Nursing, July-Aug. 2014, p. 256
- Grohskopf LA, Sokolow LZ, Broder KR, et al. Prevention and control of seasonal influenza with vaccines: Recommendations of the Advisory Committee on Immunization Practices United States 2018-2019 influenza season. MMWR Morb Mortal Wkly Rep 2018.
- Kim DK, Riley LE, Hunter P. Advisory Committee on Immunization Practices Recommended Immunization Schedule for Adults Aged 19 Years or Older – United States, 2018. MMWR Morb Mortal Wkly Rep 2018; 67:158.