Beyfortus (Nirsevimab) – a new vaccine for RSV for infants
It is always exciting to learn about the arrival of a new vaccine to the world.
As a pediatrician and specialist in pediatric infectious diseases it is fascinating to watch the change in the effects a certain infection has on children, after the introduction of a new vaccine.
But not every single new vaccine significantly alters the face of the infection it is trying to prevent, and naturally, every time a new vaccine is introduced, questions are raised about its benefits as opposed to its cost and disadvantages.
And this is the goal of this chapter. To teach you a little about this new vaccine named Beyfortus..
But promise me that before you read this chapter (which has been written for my advanced readers!), you have read and understood the important post I have on this website about RSV (link here).
What is the illness that this vaccine is given for?
This is a viral infection caused by the RSV virus. Catching this virus causes different clinical manifestations, including bronchiolitis – an infection in the lower respiratory tract (yes, you can call this a viral pneumonia if you really want to).
In most parts of the world, this virus is most dominant during the winter season.
Anyway, if you’d like to read more about RSV – follow the link I mentioned above.
What is the name of this new vaccine and which group of vaccines does it belong to?
Its trade name is Beyfortus and the generic name is Nirsevimab.
It is a monoclonal antibody against the virus. That is, it is a passive vaccine.
The difference between a passive vaccine and an active vaccine is as follows:
Active vaccine – this is when the body is given an antigen, produces antibodies against it and by doing so actively develops immunity.
Passive vaccine – this is when the body is given antibodies directly and becomes immune to the disease passively.
What is the purpose of the Beyfortus vaccine?
The purpose of the Beyfortus vaccine is to prevent the severe lung infection that RSV causes in the lower respiratory tract, and this has also been proven in the clinical trials that have been conducted.
How does the vaccine prevent RSV infection?
As mentioned above, this is a passive vaccine. The antibodies it provides protects the baby from the pathogen for a certain period of time after the vaccine has been given.
How effective is this vaccine?
According to the scientific trials, Beyfortus decreases the risk of developing severe RSV by about 80%. A new article shows an efficacy of 83%, read more here.
But we already have a vaccine for RSV, isn’t that right?
Correct. There is a vaccine called Palivizumab (Synagis) that is given to infants that are at high risk of developing severe vaccine. It is administered once a month, for 5 months, during the winter season. Beyfortus is administered completely differently:
1. Beyfortus is available for all babies, and not just those who are at high risk of developing severe disease.
2. One dose of Beyfortus suffices and provides protection for at least 5 months, which is the duration of one RSV season.
How long does it take for Beyfortus to start working?
Beyfortus starts working immediately. Afterall, the child’s body will have received antibodies passively.
Keep in mind that the immunity it provides fades within several months.
Therefore, Beyfortus does not provide permanent protection from RSV but protects babies and covers them for the duration of the first RSV season of their life, when they are at the highest risk of developing a severe infection.
Keep in mind that children and adults are prone to recurrent infections, but the chance of getting a severe infection decreases with age.
Who was this vaccine developed for?
The vaccine is intended for use in neonates and infants under the age of 1, who were born during or just before RSV season.
It is also intended for use in infants under the age of 24 months who are at risk of developing a severe infection also during the second RSV season in their life, such as children with chronic lung disease.
Has this vaccine been tested around the world? Where is it available?
Beyfortus was approved by the American FDA and the EMA (the European Medicine Agency) and is available in North America, EU countries and Great Britain as well as several other countries around the world. As of now, two million babies in countries around the world including the US, Spain and France have already received the vaccine.
How is this vaccine administered and what is the correct dosage?
Beyfortus is administered intramuscularly as a single dose:
A single dose of 50mg is administered to babies under 5kg.
A single 100mg dose is administered to babies that weigh over 5kg.
What are the side effects of the Beyfortus vaccine?
Common side effects include local tenderness, rash, redness or local swelling around the area of the injection. Severe allergic reactions were not reported in the clinical trials that were conducted. Nonetheless, I advise anyone who is taking their child to get vaccinated to ask the healthcare worker giving them the vaccine about any potential side effects.
Can the Beyfortus vaccine be given together with other scheduled vaccinations?
Yes, Beyfortus can be given concomitantly with other vaccines, and this is actually recommended. It is a good idea to administer this vaccine at the same appointment with other vaccines and by doing so to avoid the need for an additional appointment.
Beyfortus is not expected to interfere with the immunogenic reaction of other vaccines.
Where can I get this vaccine? Do children born during RSV season receive the vaccine at the hospital?
In some countries around the world, babies born during the winter season receive the RSV vaccine at the hospital, prior to their discharge after birth.
Refer to your local doctor’s office to learn more about where you can receive this vaccine, this may differ depending on where you live.
In summary, this is a new vaccine, that carries new challenges and raises lots of new questions (for new parents). Make use of this post to help you make the very best decisions for your fresh baby.
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