The pandemic caused by Covid-19 brought the flu out of focus. But this year it has come back stronger. Since the outbreak of SARS-CoV-2, respiratory viruses have altered their patterns, to the point that this season the incidence of all of them has registered abnormally high values, such as influenza A and B. However, experts They are seeing that the season does not seem to have ended.
Raúl Ortiz de Lejarazu, scientific adviser and director emeritus of the National Flu Center of Valladolid, explains that last year, 21-22, we had the flu even though there was officially no flu. “It was the longest flu that Europe has had in the entire 20th and 21st century, even if it was of low intensity. And the worst part is that it’s not over yet.”
The problem is that it seems that there is permanent flu, it has remained endemic or it has “covitalized». Before the flu season began with Santa Claus or the Three Wise Men and the trend is that this situation will continue the same next year.
The flu virus is a syndrome caused by different types, A, B, etc. “This is an indistinguishable virus from a clinical point of view that, due to its reservoir in animals, does not need humans to live and, from time to time, jumps to humans,” says Ortiz de Lejarazu.
In the last century, he recalls, “we have had major pandemics such as the 1818 flu, the Asian flu, the Hong Kong flu, and in this century, the influenza A pandemic. With the flu, we know that a new virus will regularly appear before the which we will not have many defenses ».
Fortunately, says Jordi Reina, head of Virology at the Son Espases Hospital in the Balearic Islands, these pandemic-causing viruses are not as frequent as the variations that year after year force us to make changes to the vaccine. “The virus goes at its own pace and follows its normal evolutionary process and, sometimes, the circulating flu virus is discordant with that of the vaccine, because the vaccine composition is decided in February and it begins to be introduced in October. Not like in others, like measles, which is always the same strain.
It makes no sense to only vaccinate children at risk
Jordi Reina
Head of Virology at the Son Espases Hospital in the Balearic Islands
In 2011, the World Health Organization advised flu vaccination for all children. Countries like England began to vaccinate from that year, but Spain, despite being a model in vaccination, has not done so until this year. This past season they have already begun to vaccinate children only in three autonomous communities: Andalusia, Murcia and Galicia.
First it was the recommendation of the Vaccine Advisory Committee of the Spanish Association of Pediatrics and this same year the Ministry of Health has included it in the official vaccination schedule for children between 6 months and under 5 years of age. However, points out Fernando Sánchez Perales, medical director of the Vithas Madrid La Milagrosa University Hospital and president of the Pediatric Society of Madrid and Castilla-La Mancha, “children have been vaccinated for the flu all their lives. But until now only the most vulnerable were vaccinated, barely 30% of the 10% of all children, who are those at risk.
We are late because in countries like the US they are vaccinating those under 18 and Ireland up to 17. “That is, we are going with minimums and 10 years behind,” insists Lejarazu.
We are late, other countries are already vaccinating their children
Raul Ortiz de Lejarazu
Scientific adviser and emeritus director of the National Influenza Center of Valladolid
Fernando Moraga-Llop, a pediatrician and spokesman for the Spanish Vaccinology Association, shares a similar opinion. “The Spanish Association of Pediatrics could consider universal vaccination under 18 as the best strategy to control this disease.”
The positive thing, says Reina, “is that for the first time the Ministry officially recommends it, and finances it for this age segment.” Until now, the vaccine was only recommended for children with risk factors. This was a bit of a contradiction, Reina acknowledges, “since we know that 60% or 70% of children who get sick with the flu are not at risk.” And Moraga-Llop adds a piece of information: two out of three children who are admitted with the flu do not have risk factors and more than half of those who die do not either. And another one: the flu kills every season between 14 and 20 healthy children in Spain.
The four experts agree that the problem is that there is no feeling that the flu is a deadly disease. “We have to convey that it is a risk disease and preventive measures must be taken, such as vaccination. And especially if they finance it for you, ”reina emphasizes. “There’s no real reason not to get vaccinated.”
To better understand the impact of the flu in the world, Ortiz de Lejarazu gives the following example: «Each year the equivalent of the population of China is infected with the flu; those hospitalized would be equivalent to the entire Community of Madrid, while mortality would be similar to the population of Seville, if it is more lethal, or like Valencia or Zaragoza, if it is less serious» .
Pediatricians are vaccination enthusiasts
Fernando Sanchez Perales
Medical Director of the Vithas Madrid La Milagrosa University Hospital and President of the Pediatric Society of Madrid and Castilla-La Mancha
For this reason, vaccinating children, in addition to the individual effect, has a collateral consequence. As a public health measure: protect the elderly.
Moraga explains that children are the most important actors because they are the most infected, between 20 and 40%. They are the main transmitter and are difficult to diagnose. And finally, “they are in contact with more people.” In other words, Queen’s note, «they are introducers, disseminators and maintainers; but also sufferers».
In a flu season in Spain, according to the surveillance system, those under 15 years of age have the highest incidence of flu per 100,000 inhabitants. For Ortiz de Lejarazu, “the flu is a systemic disease that infects children and young adults and kills the elderly or those with vulnerabilities.”
Pediatricians now have the role of convincing parents of the importance of vaccinating their children. “Pediatricians are enthusiastic about vaccination in general and we must encourage parents,” says Sánchez Perales. For this they have help: the different vaccines. “That’s how we’re going to recommend it.”
Vaccinating those under 18 is the best strategy
Fernando Moraga-Lop
Pediatrician and spokesperson for the Spanish Vaccinology Association
Some autonomies have already chosen to include some new childhood vaccines in their official vaccination schedules for the following season (2023-2024). Others are evaluating it. This year the Community of Murcia has used new options for the next season, Castilla y León has already announced it; which suggests that the other autonomies can follow this path.
biological opportunity
Ortiz de Lejarazu adds another relevant fact. “The first time a child is infected marks their immune system for life as it produces an immune footprint that allows them to respond better to a virus.”
Experts believe essential campaigns for the dissemination of vaccines to families. “It is very important that families know that flu vaccination is recommended for children under 5 years of age, and that the vaccines are financed by the National Health System so that they can take them to be vaccinated.”
Finally, Moraga-Llop does not want to overlook the fact that the vaccines must be administered by health personnel. “You don’t have to self-vaccinate.”