Post #40 Flu Vaccine Update 2013-2014 (Quadrivalent vs Trivalent)

How is the flu vaccine formulated?

Flu viruses are always changing. Each year, experts study thousands of flu virus samples from around the world to figure out which viruses are making people sick and how these viruses are changing. With this information, they forecast which viruses are most likely to make the most people sick during the next flu season. These strains are then used to make the flu vaccine for the next flu season.

The 2013-14 U.S. trivalent influenza vaccines will contain:

*an A/California/7/2009 (H1N1)pdm09-like virus
*an A/Victoria/361/2011 (H3N2)-like virus
*a B/Massachusetts/2/2012-like virus

The newer quadrivalent vaccines will include an additional vaccine virus:

*a B/Brisbane/60/2008-like virus

While the H1N1 virus and the H3N2 virus used to make the 2013-2014 flu vaccine are the same viruses that were included in the 2012-2013 vaccine, the recommended influenza B vaccine virus(es) are different from those in the 2012-2013 influenza vaccine for the Northern Hemisphere.

 
When to get vaccinated?

Yearly flu vaccination should begin in September or as soon as the vaccine is available and continue throughout the influenza season, as late as March or beyond. The timing and duration of influenza seasons vary.

In our area, a local pediatrician friend has already reported 2 cases of flu "A" seen in siblings this past week at their office.  A rapid flu test was used, however at this time no further confirmation is available.  If confirmed, this may point towards an early and long flu season.

While influenza outbreaks can happen as early as October, most of the time influenza activity peaks in February or later. About 2 weeks after vaccination, antibodies that provide protection against influenza virus infection develop in the body.


How many shots will my child need?

This year's seasonal flu vaccine will again include the Novel 2009 H1N1 vaccine which was used during the recent global pandemic and which was also included in the past three seasonal flu vaccines. This means your child will only need to get vaccinated with ONE TYPE of flu immunization this year.

If your child is 9 years or older, regardless of what flu immunizations have been given in the past, they will only need ONE immunization this flu season.

However, if your child is under 9 years of age, they may need TWO immunizations this year. See the chart below to assist you in knowing how many shots your child will need this flu season.

If your child needs 2 flu vaccines this year, they should be spaced apart by a minimum of 4 weeks (28 days). There is no deadline by which the 2nd flu vaccine needs to be completed, but once the minimum 4 weeks has passed, the sooner the better as your child will have optimal protection only after the 2nd immunization.

	0 flu shots since July 2010	1 flu shot since July 2010	2 flu shots since July 2010
Under 9 years of age	2 flu shots needed	2 flu shots needed	1 flu shot needed
9 years of age of older	1 flu shot needed	1 flu shot needed	1 flu shot needed

If your child is under 6 months of age, they are too young to receive the flu vaccine.  It is imperative for all surrounding family members (and caretakers) to receive the flu vaccine as soon as possible to create herd immunity.  Essentially, if everyone surrounding the infant is protected, it decreases the risk that the baby will be exposed to the live flu virus.

Quadrivalent vs. Trivalent flu vaccine

Traditionally, the flu vaccine covers 3 different strands of the flu virus (2 "A" strands and 1 "B" strand) and is labeled a trivalent vaccine.  Starting  this year, some of the the flu vaccine products will be expanded to include 4 different strands of the flu virus (2 "A" strands and 2 "B" strands) thus adding 33% more protection.

This means that both the trivalent flu vaccine and the quadrivalent flu vaccine will be available this year.  Within approved indications and recommendations, no preferential recommendation is made for any type or brand of licensed influenza vaccine over another by the CDC (Center for Disease Control).

The manufacturing process for the quadrivalent vaccine is the same as the trivalent vaccine and as such there should be no increased adverse effects in using the newer quadrivalent vaccines.

At our office, the trivalent injection vaccines are shipping out sooner than the quadrivalent injection vaccines (with no shipping date for the quadrivalent injection vaccines given as of 8/17/13).  The quadrivalent nasal vaccines are shipping now.  Unfortunately, children under 2 years of age and those with asthma (and a few other scenarios - please see CDC website) cannot receive the nasal vaccine and must receive the injection vaccine.

It is this author's opinion that when possible, a quadrivalent vaccine is preferable as it protects against an additional "B" strand that the trivalent flu vaccine does not.  However, from a timing standpoint, if the quadrivalent is unavailable, it is probably more important to get the trivalent vaccine as soon as possible, rather than to wait on an unknown availability date.

In the event that a child will need two flu vaccines this year, it is ideal to get as many quadrivalent doses as possible.  The most ideal would be to receive both flu immunizations with the quadrivalent vaccine. 

However, if this is not possible or ideal because of vaccine availability, the next best scenario is to receive at least one quadrivalent and one trivalent, although this is only marginally better than receiving two trivalent shots.  Because of timing and availability, if both shots given are the trivalent vaccine, this is still preferable to waiting on the quadrivalent vaccine, if availability is uncertain.

Children receiving the nasal flu vaccine and requiring two doses do not have to worry about this issue, as all nasal flu vaccines are expected to be quadrivalent this year.

Parents should know that in a child who requires two flu immunizations this year (see chart above), the reason it is recommended to get the second immunization is that in a naive immune system, a single injection of a flu strand does not afford very good protection.  (This is pertinent mostly with the injection as the nasal flu vaccine affords good protection with one dose - however two may still be recommended per the CDC algorithm.)  For ideal protection, a booster of the same strand should be given as soon as possible.

This is why a single injection of the trivalent vaccine (which has 3 flu strands) followed by a booster injection of the quadrivalent vaccine (which has 4 flu strands) or vice versa is only marginally better than receiving two trivalent flu shots. 

In the preceding scenario, the 2nd "B" Brisbane strand (which is only included in the quadrivalent vaccine) would only be received once.  Thus, there would be good protection against 3 strands of flu and only marginal protection against the quadrivalent-only strand of Brisbane "B"  flu.

In the end, practically speaking, timing is probably more important than worrying about quadrivalent vs. trivalent flu vaccine.  When possible the quadrivalent should be received, but when the quadrivalent is unavailable it is probably best to move forward with the trivalent vaccine.   The faster the flu season infects children, the more important timing becomes.

If the quadrivalent vaccine is unavailable, some parents may initially opt to get the readily available trivalent flu shots (once or twice) and then desire to follow-up with two additional boosters of the quadrivalent flu shots as they become available. 

This could possibly lead to a scenario where a child receives 3 or 4 flu shots during this season (1-2 initial trivalent shots followed by two quadrivalent shots).  This would ensure early protection against the 3 strands of flu in the trivalent vaccine followed by addtional protection against the Brisbane "B" strand which is only covered by the quadrivalent vaccine.

As the author of this blog, I am unsure about the safety of receiving 3 or 4 flu shots in a single season.  The flu shot has been historically shown to be very safe with few side effects, but I am unsure of the data regarding this many shots.  

The pediatrician and parents will have to weigh the risk and prevalence of the Brisbane "B" strand vs. the unknown potential side effects of receiving 3 or 4 flu shots.  This author's educated guess is that there is little risk to a 3rd or 4th flu vaccine in a single season, but at this time I have no specific data to support this claim.

At our office, the quadrivalent vaccine will be preferentially given, when in stock, unless otherwise requested by the parent.

Flu Vaccine Egg Allergy Protocol (per CDC)

1. Can the child eat lightly cooked egg (e.g., scrambled egg) without reaction?

If so, the vaccine should be administered per usual protocol

2. After eating eggs or egg-containing foods, does the child experience ONLY hives?

If so, the vaccine should be administered and the child will be observed for reaction for at least 30 minutes following vaccination

3. After eating eggs or egg-containing foods, does the child experience other symptoms such as: cardiovascular changes (e.g., hypotension), respiratory distress (e.g., wheezing), gastrointestinal symptoms (e.g., nausea/vomiting), reaction requiring epi-nephrine, or reaction requiring emergency medical attention?

If so, the child shoud be referred to an allergist with expertise in the management of allergic conditions for further evaluation.

When will the vaccines be available at Blue Fish Pediatrics Memorial?

At Blue Fish Pediatrics Memorial, during regular office hours (starting August 19, 2013), the flu vaccine will only be available at well visits for all patients of Blue Fish Pediatrics Memorial and family members living in the same household with patients under 6 months of age.  Flu vaccine will also be administered during sick visits at their doctor's recommendation.

The flu vaccine will be administered at all well child visits until supplies are exhausted (no additional appointment or phone call is required).

To help accommodate our busy families, we have designated four Saturdays for flu shots (the clinic will still be open on these Saturdays for sick patients).

Because of the high volume, these flu clinics are for BLUE FISH MEMORIAL PATIENTS ONLY. Weekday vaccine appointments will be made for Cypress patients who arrive at these flu clinics. For more information, please see the CYPRESS flu newsletter.

The dates of the Saturday Blue Fish Pediatrics Memorial flu clinics:

Saturday    Sept 14, 2013          8:00 AM—1:00 PM

Saturday    Sept 28, 2013          8:00 AM—1:00 PM

Saturday    Oct 12, 2013           8:00 AM—1:00 PM

Saturday    Oct 26, 2013           8:00 AM—1:00 PM

Any Blue Fish Memorial patient or parent is eligible to receive the flu vaccine on these four specially designated Saturdays.  Also eligible are any family member(s) living in the same household with patients under 6 months of age.  On these specially designated Saturdays you will not need an appointment and can walk-in at your convenience for the flu vaccine.

·        The availability of certain flu products may be limited towards the end of the flu season.

·        The intradermal flu vaccine will NOT be available at Blue Fish.

·        The recombinant flu vaccine will NOT be available at Blue Fish.