Flu vaccine spray: what it is and how it works

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This year, more than ever, the flu vaccination is important in order to be able to recognize the symptoms of Covid-19 more easily and to protect children from the complications of 'seasonal flu. In Lombardy, to ensure effective coverage among children, spray flu vaccines have been purchased to be administered to children between 2 and 10, and this type of vaccination can then also be extended to children up to 18 years of age. For the This new type of vaccine will be used for the first time in the country. Let's see how it works thanks to the help of Maurizio Bonati, Head of the laboratory for maternal and child health of the Mario Negri Institute of Pharmacological Research.

In this article

  • What it is and how it works
  • How it is administered
  • Up to what age
  • When it is not recommended
  • False contraindications
  • Safety and side effects
  • The classic flu shot
  • Influenza vaccine spray in Lombardy

What it is and how it works

The experience of vaccination is not always pleasant, especially for younger children. Thus, at least for the flu vaccination, a vaccine has already been patented for 10 years that does not require needles and syringes, but only one nasal spray. In Del Paese, however, it had never been used until now, although the European Center for Disease Control and Prevention includes it among the usable flu vaccines.

Unlike the classic flu vaccine, the spray contains inside still live influenza viruses attenuated, but less aggressivi compared to those that normally circulate in autumn and winter. The flu strains contained are treated to resist the temperature of the nasal mucosa so that they can multiply inside it without affecting the lower respiratory tract.

How it is administered

"This type of vaccine works like a common nasal spray, you make it two sprays, one per nostril "explains Dr. Maurizio Bonati. No needles and syringes therefore and no pain due to the sting so hated by the little ones." Usually they are necessary two doses of the vaccine to be carried out one month later to guarantee coverage, but only one will be carried out in Lombardy after the positive opinion of AIFA ". 

Indeed, just recently the Ministry of Health in a note (0038627- 26/11/2022-DGPRE-MDS-P) specified that "AIFA considers adequate protection provided by the first dose of vaccine, so he believes that a single dose could be given to children who have never been vaccinated against the flu. In analogy to what is already in place in some countries (…) this strategy would make it possible to double the vaccination offer with materially available doses ".

Up to what age

"It depends - says Dr. Bonati - in Del Paese the spray flu vaccine can be administered starting from two years of age up to 18 years of age, while in other countries, such as the United States, the spray vaccine is used up to the age of 49 ".

When it is not recommended

Absolutely not earlier than 24 months of age. The use of the spray flu vaccine is not recommended in children under the age of two because it may cause temporary breathing problems.

For the spray flu vaccine then, more or less the same rules apply as for the classic flu vaccine. It must therefore not be administered to subjects who have manifested anaphylactic-type reactions a previous vaccination or one of the components of the vaccine. Even if the child was sick, it is advisable to postpone the vaccination after recovery.

False contraindications

However, it is not true that the flu vaccine cannot be carried out in the case of:

  • egg protein allergy
  • minor acute illnesses

Safety and side effects

But this new vaccine it's really effective against the flu? In the past, the effectiveness of the spray flu vaccine had been questioned. In 2022, the United States Center for Disease Control advised against this type of vaccination as it proved less effective than the classic flu shot. A later study also showed that the results obtained with the administration of the spray flu vaccine were below expectations for some age groups.

In 2022, however, after the publication of new efficacy data, several health authorities resumed recommending the spray flu vaccine.

Let's see what Dr. Bonati of the Mario Negri Institute for Pharmacological Research.

"To date we do not have many studies on the use of the spray flu vaccine, but we know that it has been patented for 10 years now and that it is used without problems in other countries. The studies available are positive and large reports of adverse reactions have never been received. . There may be a greater fear because they are attenuated live viruses and this could lead to an increase in side effects, but so far the accessible data show that we need to rest assured. "

Some may still occur following a vaccine side effects. Regarding the spray flu vaccination we find:

  • nasal congestion
  • migraine
  • decreased appetite

The classic flu shot

What changes between the classic flu vaccine and the spray one? There are essentially two differences, in addition to the method of administration, which concern the content of the vaccine andage of the little patient.

Classic flu vaccines are administered through aintramuscular injection and they contain a inactivated version of the virus which elicits an immune response, but without making the recipient of the vaccine sick. While as regards that spray, as we have seen it is simply inhaled and inside we find live attenuated viruses. Thanks to the vaccine, of whatever type it is, our immune system recognizes the flu virus and "fights" it, thus preventing the development of the infection and any disease.

If for the spray flu vaccine it is necessary to wait until the child has 2 years, with the classic vaccine it is also possible to vaccinate infants starting from 6 months of age.

Influenza vaccine spray in Lombardy

At first, the flu shot, Fluenz Tetra Spray, had been bought for children between 2 and 6 years, but the Lombardy Region has decided to expand the audience of possible beneficiaries. The Councilor for Welfare of the Lombardy Region has in fact announced that "the flu spray vaccine can be used in a single administration and will be extended to children up to 10 years"The doses purchased by Lombardy amount to about 500 thousand units and should they advance, starting from 7 December it will be possible for the territorial social welfare agencies and for pediatricians in the region to offer for free the vaccine also for children up to 18 years and while stocks last. Lombardy is the first Del Paesena region to use the spray flu vaccine, used until now in Great Britain and the United States.

It must have been one good choice? Dr. Maurizio Bonati has some doubts "it would seem a bit like one improvised move, then we hope it is a correct move, but at the moment it is not clear what the region's strategy is for vaccination campaign. If the vaccination is extended to children over 6 years - continues Bonati - it means that many doses of the vaccine have not been used and therefore it has been a bit of a flop. At the moment, therefore, it seems more a move dictated mainly by politics and not by public health ".

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