The influenza vaccine: What you need to know.
Which flu vaccine is best to give this year for little ones? Flu Mist is back and is it better?
Thanks to Sara Lattanzio Triglia from Youngstown for the excellent question and topic idea!
Flu season is upon us and now is the time for everyone older than 6 months old to be vaccinated against influenza. Vaccines save lives—and vaccination against influenza is no exception.
Before I discuss the details of the differences between the types of vaccines available and who should get which one, let’s review some background on influenza and the creation of the flu vaccines. (If you want to skip ahead, I summarized the take home points at the end!)
A BIT OF BACKGROUND ON THE FLU VACCINE
The influenza vaccine has always been a bit more complex than other vaccines for a variety of reasons. Unlike other vaccines such as MMR which, in most cases, only requires 2 doses for lifetime protection, vaccination against influenza is necessary on an annual basis.
Influenza is a particularly tricky and challenging virus. Unlike most viruses, influenza has a rapid rate of mutation. Small changes are continually made to the virus as it travels around the world and infects people. The virus, by constantly changing, makes it much more difficult for a person’s body to respond quickly and stop the virus from continuing to be spread. Thus, every year, there is slightly different version of the influenza virus that arrives in the United States. So, a new version of the vaccine is needed to be effective against the new version of the influenza virus.
The other tricky part is that development of the vaccine is essentially educated guessing. If researchers waited to make the vaccine until we knew exactly which form of the virus had arrived in the US, it would be too late and lots of people would get sick and could potentially die. So, instead, a version of the vaccine is made based on which strains of influenza are isolated about 6 months prior, on the other side of the world. The expectation is that similar versions will be headed to the US for our winter season. Many times, our scientists are right but sometimes, less so. This means that sometimes the influenza vaccines is excellent at protecting against the flu, and other times it is not quite as good.
Remember that no vaccines is perfect and it is still possible to get the flu even if you were vaccinated.
THE FLU VACCINE DID NOT GIVE YOU THE FLU.
This is simply not possible based on the way it is made. The injectable form is made from a dead part of the virus. A dead virus CANNOT give you the disease. The nasal mist is a live virus, but is so weak it is basically helpless against the massive army of your immune system. Sure, you might get some unpleasant symptoms from getting your flu shot, but this is not the same as getting the actual disease caused by the flu virus.
WHICH ONE SHOULD I CHOOSE FOR MY CHILD??
Now, let’s talk about your options and which vaccine to get and give your children this year.
The influenza vaccine comes in two general forms, the nasal mist and the injectable form. In past years, both the nasal mist and the injection were able to be given interchangeably, with some exceptions based on age and certain specific medication conditions.
However, a review of the effectiveness of each of the vaccine form during a 6 season span from 2010-2017 showed that the nasal mist was less effective than the injection against protection from the H1N1 strain of influenza. Due to this difference, the nasal flu was not strongly recommended in the 2017-2018 season but after a few tweaks, the nasal form was reintroduced and given in 2018-2019 season. Due to the changes made for last year’s vaccine, it is expected that the nasal mist is more effective than it was previously and the CDC is now (i.e, for the 2019-2020 season) recommending both the mist and the injectable form without preference of one over the other.
The injectable influenza vaccine is indicated for children 6 months and older. The nasal mist can now be given as an alternative to the injectable vaccines and is available for children 2 years and older.
A few important notes:
1) The flu mist uses a live but weakened version of the influenza virus. The injectable version is made with an inactivated, i.e., dead, version of the virus. Both are preventative again the flu. NEITHER VERSION CAN CAUSE THE FLU.
2) If your child has an ALLERGY TO EGG, she/he CAN SAFELY get ANY of the flu vaccines. This includes children who have a history of anaphylaxis to eggs. These children, should, however, receive their vaccines under a doctors supervision.
3) Children aged 6 months through 8 years old getting their first flu vaccine ever need TWO influenza vaccine doses, 1 month apart. The following year, and every year after that, only one vaccine is needed. Note that if your child is given a flu vaccine at 8 and then turns 9 during that same flu season, a second vaccine should still be given. However, If your child is 9 years old at the time the first flu vaccine is given, only one vaccine is needed.
4) Since the NASAL FLU MIST is a live vaccine, the following, unique rules apply. Please make sure to talk to your doctor if any of these apply to your child.
Children who should NOT receive the NASAL FLU MIST:
- age is less than 2 years old
- diagnosis of wheezing or asthma under age 4 years and with caution in kids 5 and older
- the child is immunosuppressed (unless approved by your doctor)
- the child is in close contact with severely immunosuppressed persons
- history of severe allergic reaction to the vaccine
- the child is currently using aspirin. Children should only ever be taking aspirin if specifically directed by a doctor. Otherwise, never give aspirin to a child (could have a whole other post on this).
- if the patient is pregnant
- use with caution in children with a history of Guillain-Barre syndrome within 6 weeks of a previous flu vaccine
- if they have received the injectable influenza vaccine in the past 48 hours
- with caution if your child is sick and has a fever. It may be worth waiting for a few days until symptoms have resolved and then giving the vaccine. Please talk to your doctor to discuss the right time.
5) Even if you do still get the flu: Studies from recent flu seasons showed that people who were vaccinated had a less severe course and were less likely to be hospitalized, less likely to require ICU level care, and less likely to die from the flu than those who contracted influenza and were NOT vaccinated.
6) Know that there are a few different manufacturers of the injectable forms of the injectable flu vaccines. Other than one specific version that is grown on cell culture instead of egg and only available for kids older than 4 years, the injectable flu vaccine are essentially the same, other than dosing. One manufacturer has a different dose for kids 6-35 months, but the others use the same dose for everyone. Your pediatrician’s office will generally just choose one.
Whew! That was a lot of information. IMPORANT TAKE HOME POINTS:
1) Except under very special circumstances ALL children older than 6 months should get vaccinated against influenza. Influenza can be deadly, even in otherwise healthy children. Please remember that vaccines save lives.
2) Children aged 6 months though 8 years old getting vaccinated for the first time need TWO influenza vaccines, 1 month apart. Again, this is only necessary the first season they receive the flu vaccine.
3) The flu mist is again available for children older than 2 years of age. According to the CDC, there is currently no preference between the mist compared to the injection. We are told that the flu mist is better and more effective than before, however, researchers are continually gathering data to evaluate this recommendation. The improved nasal mist has only been used for one season (2018-2019), so strong data to support its improved efficacy are not yet available. Because of this, some pediatric offices are only offering the injectable form and not offering the nasal mist until more robust data are available.
4) There are some special circumstances in which children are NOT eligible for the flu mist, so please check with your doctor to make sure it is safe. When in doubt, give the injectable flu vaccine.
5) You can still get the flu even if you get vaccinated. Don’t be discouraged!! Studies done looking at the last two flu seasons show that people who are vaccinated have a less severe course and are LESS LIKELY to get hospitalized, need ICU level care, or die from the flu. In other words, if you get vaccinated, you might still get the flu, but it won’t be nearly as bad.
References:
1)Frequently asked influenza questions 2019-2020 season. https://www.cdc.gov/flu/season/faq-flu-season-2019-2020.htm?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fflu%2Fseason%2Fflu-season-2019-2020.htm#anchor_1568639330820
2) Influenza vaccine for the 2019-2020 season. https://www.fda.gov/vaccines-blood-biologics/lot-release/influenza-vaccine-2019-2020-season
3) AAP updated vaccine recommendation for 2019-2020 flu season. https://www.aap.org/en-us/about-the-aap/aap-press-room/Pages/AAP-Updates-Vaccine-Recommendations-for-2019-2020-Flu-Season.aspx
4) Thompson, MG et al. Influenza vaccine effectiveness in preventing influenza-associated intensive care admissions and attenuating severe disease among adults in New Zealand 2012–2015. Vaccine. Volume 36, Issue 39, 18 September 2018, Pages 5916-5925 https://www.sciencedirect.com/science/article/pii/S0264410X18309976?via%3Dihu
