Tag: adult-dose

Did Dr. Bob Uncover a CDC Plot to Give Adult Flu Shots to Babies?

Have you heard the news?

Uh, the ACIP can't request a license for a vaccine...
Uh, the ACIP can’t request a license for a vaccine…

Dr. Bob and his new podcasting side kick think that the “CDC wants the FDA to approve adult doses of the flu vaccine for babies, because the normal half-doses approved for babies don’t work well enough.”

Did Dr. Bob Uncover a CDC Plot to Give Adult Flu Shots to Babies?

This is likely going to surprise Dr. Bob, but many infants already get the same dose of flu vaccine as adults.

Both FluLaval and Fluarix are given at the same 0.5ml dose, containing 15 µg of HA per vaccine virus, to infants, older children, and adults.

Fluzone, on the other hand, is still given at a 0.25ml dose, containing 7.5 µg of HA per vaccine virus, to children between the ages of 6 months to three years, and a larger 0.5ml dose to older kids and adults.

Why the differences?

“In a randomized trial comparing immunogenicity and safety of 0.5 mL FluLaval Quadrivalent with 0.25 mL Fluzone Quadrivalent, safety and reactogenicity were similar between the two vaccines.”

Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices—United States, 2018–19 Influenza Season

Because they are just as safe at the lower doses and might actually work better.

Then why did we ever use a lower dose for infants?

That recommendation was based on the older, whole-virus version of the flu shot, which did cause more side effects for infants when given at a full dose. We now use split-virus flu shots that don’t have this problem.

And now, the manufacturer of Fluzone has done a study, and not surprisingly, they have also found that “safety profile of a 0.5 ml (full-dose) is similar to 0.25 ml (half-dose) and may be more immunogenic.”

So they are submitting a BLA to the FDA for the use of the 0.5ml dose of their flu vaccine for infants.

What about the idea of an “adult dose of mercury” for infants?

Over 80% of flu vaccines were thimerosal free this year. You almost have to go out of your way to get your kids a flu vaccine with thimerosal, so no, this won’t mean an “adult dose of mercury” for your infant.

Most importantly though, if you understand how vaccines work, you know that the dose of vaccines for kids and adults is not calibrated by weight or age, so none of this really matters. The immune reaction that helps antibodies travel all through your body starts locally, near where the vaccine was given, so a 20-pound infant and a 200-pound adult can get the same dose of flu shot and both can be protected.

More on Dr. Bob’s CDC Plot to Give Adult Flu Shots to Babies

Vaccines for Adults

Adults need to get vaccines, just like kids.

Vaccines for Adults

Of course, they don’t get as many vaccines as kids, since many adults are either already immune or are no longer at risk to many vaccine-preventable diseases.

The adult immunization schedule can help adults figure out which vaccines they need.
The adult immunization schedule can help adults figure out which vaccines they need.

Adults do get:

They can also get most other vaccines, except Rotavirus and DTaP (they get Tdap instead), that they need because they lack immunity. Although it is not on the immunization schedule, adults can get the polio vaccine if necessary.

Another question that comes up concerning adult vaccines is why do adults and children get the same vaccines. In other words, are vaccines calibrated taking into account a child’s weight and age?

Donald Trump often says that he is against vaccines because we give “one massive dose for a child,” going on to say that they should get smaller dosages in a more spread out schedule. Some others agree, claiming that infants shouldn’t get the same dose of vaccine as an adult.

But do they?

Not always. There are pediatric versions of the influenza, hepatitis A, hepatitis B, and DTaP (vs Tdap) vaccines.

It doesn’t necessarily matter though. Unlike medications you take, like Tylenol or an antibiotic, vaccines don’t go through your whole body to work, so your size doesn’t matter.

More on Vaccines for Adults