The 'enigma' Of Children And Covid: Is It Necessary To

The ‘enigma’ of children and Covid: is it necessary to vaccinate them to achieve group immunity?

A new study published in the journal ‘JAMA Network Open’ suggests that it would not be essential as long as some variables were considered.

Until now, there are no vaccines for Covid-19 authorized in children.

As the vaccines against Covid-19 are deployed in Spain, the composition of the groups with priority to receive the sera from the different manufacturers is unraveling, at least from those who have their product authorized by the European Union.

Among the 15 groups originally specified, there is one for which there is still not a single proven vaccine: the child population. All the preparations that are currently available are aimed at the population over 18 years of age.. Only one of them, Comirnaty, developed by Pfizer and BioNTech, has lowered the age to 16.

Obviously, it was something that the pharmaceutical companies had to solve and, at present, there are several trials underway to check the efficacy and safety of the vaccines in more or less large groups of minors. for now, only Pfizer requested the authorization of its vaccine in the United States for adolescents between 12 and 15 years of age at the beginning of the month, and will do the same this Wednesday before the European Medicines Agency. For the rest, it will still be a few months before results are presented and the indications of these products may include them.

But it is necessary? This is the question posed by a study published in JAMA Network Open, Journal of the American Medical Association. In it, it is stated that a moderately successful screening strategy for asymptomatic infections in children can control the spread of the virus although vaccination coverage among adults does not reach 50% of the population. In other words, an effect similar to that of group immunity would be achieved.

It is a theoretical model that, however, has taken into account numerous variables: from the effective reproductive number of the virus to the efficacy of vaccines against severe Covid-19 (95%) and their ability to prevent contagion ( fifty%).

Screening of asymptomatic infections

The researchers, led by Alison P. Galvani of the Yale School of Public Health, took the United States census as a reference to stratify and determine the breadth of different age groups and analyzed various hypotheses of the vaccinated population, from none at all up to 60% coverage. They also calculated that 10% of the population would already have pre-existing immunity from having passed the disease.

Thus, with a vaccination coverage of 40% of adults (since the older groups were priority groups, they accounted for 80% of those vaccinated among those over 50 and 22% among adults up to 49 years of age) it would only be necessary to detect one of the every 10 asymptomatic infections in children within two days of infection to keep the attack rate (ie, the population infected in an entire year) below 5%. If it takes three days to detect them, the number of identifications would have to be raised to one in 7.

In the case of increasing coverage to 60% of adults, it would only be necessary to detect 6% of asymptomatic infections within three days of infection.

“In a scenario where vaccines are only available for adults, our results show that if just one in 10 infected children were identified within two days of infection,” the authors note, “the global attack rate could be reduced to less than 5%.

Vaccinating children is not essential

With 70% of people vaccinated in Spain at the end of summer, as the Government has repeatedly announced, there will still be months before results are presented on the efficacy of preparations against Covid-19 in children, so the strategy proposed in the study “may be a good option”, reflects Angel Hernandez Merino, member of the Vaccine Advisory Committee of the Spanish Association of Pediatrics.

“Childhood vaccination will depend on three things,” he says. “That there are safe and effective vaccines; that the control of the transmission of the virus in the community needs to control and reduce childhood transmission, and that it be possible to demonstrate that vaccination stops this transmission”.

The important point is the second. “In September it will be time to reflect on how community transmission is, if we have achieved the goal of reducing it. Then, it will not be necessary to vaccinate children“.

This does not mean that trials are stopped. “Childhood vaccines must be done and have them prepared. If the case arises, if not necessary, you have to save them”.

As is the case with the adult population, Hernández points to possible vulnerable groups of children who may need this vaccine, such as those who are immunosuppressed. “If there is vulnerability and risk of infection, selective vaccination can be considered.”

The pediatrician points out that, beyond the Pfizer vaccine for adolescents, the rest of the preparations and ages will not have their results before the end of the year, so the health authorities will have several months to make their final decision.