Mommy T's adventures; bringing up Baby T

Normal and preservative-free vaccines: what’s the difference

It is said that motherhood transforms women. That isn’t merely a statement; there is a modicum of truth there as the moment we hold the little bundle of joy in our arms, its like the entire wiring in our brains changes. For example, when I was a new mother I was very interested in everything that was related to child care. After all I was in charge of lots of decisions. One such decision was vaccination and the kinds of vaccines deemed the safest and most effective. The kind of research I did, would put an earnest PhD student to shame. Which brings me to the topic I want to talk about today: vaccines that don’t have preservatives.

Have you ever wondered what ingredients are present in a vaccine? Well we know from school level science classes and the time spent at the paediatrician’s office that a vaccine contains antigens for a particular disease. However, the antigen is not the only component present in a vial of vaccine. They also contain additives such as stabilizers, conjugating agents and preservatives. (1)


Like any other consumable product, vaccines are also subject to fungal and bacterial growth. This is especially true in the case of multi-use vials where the vaccine quantity is sufficient to immunize more than 1 person. Examples of preservative containing vaccines are those against diphtheria, tetanus and pertussis (DTP), hepatitis B, Haemophilus influenzae type b (Hib), rabies, influenza and meningococcal diseases. (2)

The preservative that has been used most commonly is Thiomersal. Thiomersal contains ethyl mercury which is used to prevent bacterial and fungal growth in inactivated vaccines most often the ones in multi-dose vials. It is also used during the production of vaccines, both to inactivate certain organisms and toxins and to help maintain a sterile production line. (3) Live vaccines, such as the oral polio drops and the MMR or measles, mumps and rubella vaccines, do not contain thiomersal, because it would kill the immunizing component.

What’s the big deal about Thiomersal?

Mercury is poisonous and extremely harmful to humans. Generally exposure to mercury even in small quantities is considered to be dangerous and more so when the child is in utero (foetus stage) or in its early life. Some researchers have claimed that the presence of thiomersal in vaccines is dangerous and should be avoided at all cost. A small study published in 1998 by a British doctor claimed that kids who had taken certain vaccines were developing autism. Chaos theories sprouted overnight which gave rise to a whole new generation of parents who were refusing to vaccinate their kids at all. (4)

Conspiracy theories apart wouldn’t it be better if the manufacturers eliminated thiomersal from vaccines?

Thiomersal has been used in vaccines since the 1930s and there is little evidence that vaccines or preservatives in vaccines have given rise to new health conditions. Additionally, thimerosal has been given an all clear.

Still, due to rising concerns, manufacturers decided to reduce and start eliminating preservatives in vaccines. This is how we have preservative free vaccines in the market.

As a mother, I would prefer to be extra safe while vaccinating my baby. So, I tell all my friends to go in for these vaccines after discussing with their child’s pediatrician.

What’s #YourCareQuotient? How much do you understand your child when it comes to sleep patterns, feeding and vaccination? Take the easy, interactive quiz that guides you and get the childcare guide now.




  1. Ramya Ravindra Barithaya

    Informative information, helpful ?

    • mommyingbabyt

      thank you

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

© 2024 Mommying BabyT

Theme by Anders NorenUp ↑