The anti Covid vaccines for babies from Pfizer and Moderna under the magnifying glass of American experts

AFP, published Wednesday 15 June 2022 at 19:59

Unsurprisingly, parents of infants and young children should be able to vaccinate against Covid-19 in the United States this next week: American experts on Wednesday examined Pfizer’s and Moderna’s vaccines for the little ones, a crucial first step in their justification.

After waiting months for clinical trials to be conducted, the two companies have submitted their regulatory submission for children ages six months to four years for Pfizer and six months to five years for Moderna.

As in many countries, this is the last age group not to have access to this protection.

The dosage has been adjusted: it is a quarter of that of adults for Moderna (25 micrograms versus 100 for adults) and a tenth for Pfizer (3 micrograms versus 30).

Although the youngest are less susceptible to Covid-19, about 480 children under the age of 4 have died from it in the United States. Hospitalization rates also increased sharply for this age group during the wave associated with the Omicron variant.

“We must be careful not to become indifferent to the deaths of children given the overwhelming number of deaths among elders,” said Peter Marks of the United States Medicines Agency (FDA) at the opening of the meeting. “Every life matters.”

The approval process is carried out in several stages. Independent experts are responsible for reviewing all available data during Wednesday’s live webcast discussions. At the end of the day, they will vote to recommend or not approve these vaccines for the youngest.

In the event of a positive opinion, the FDA, whose decisions are used as a reference worldwide, could then quickly grant its approval.

About 10 million doses would then be immediately sent to all corners of the country before millions more would be administered in the following weeks, the US government said.

The injections could start as soon as next Tuesday, as soon as the Centers for Disease Control and Prevention (CDC) give the green light. The CDC experts will meet them this Friday and Saturday.

– Pfizer in three doses –

The main difference between the two products is the number of vaccinations required: Moderna’s vaccine is still given in two doses a month apart.

Pfizer’s is given immediately in three injections, two doses of which failed to elicit an adequate immune response due to the low dosage. The first two injections of Pfizer will be given three weeks apart, with the third eight weeks after the second.

However, a Moderna representative, Jacqueline Miller, said Wednesday that trials of administering a third dose are already being planned. But “starting the injection series now is crucial to protect children this summer,” she said.

Both vaccines are safe and effective, according to the FDA, which released its own analysis of clinical trials late last week to provide experts with a basis for discussion.

According to a preliminary estimate, the vaccine from the Pfizer-BioNTech alliance proved to be 80% effective against symptomatic forms of the disease. But that number is based on a very small number of positive cases, the FDA qualified.

Moderna’s vaccine has been shown to be 51% effective in babies aged 6 months to less than 2 years and 37% effective in children aged 2 to 5 years. These numbers are consistent with the efficacy observed in adults against the Omicron variant, according to the American agency. However, the vaccine still protects them well against severe cases of Covid-19.

– impatience or skepticism –

In terms of side effects, about a quarter of the toddlers who received Moderna developed a fever, especially after the second dose. It usually subsided after a day.

In Pifzer, the rate of fever observed was comparable between the children who received the vaccine and those who received placebo.

While some parents eagerly await the opportunity to vaccinate their offspring, others will no doubt be skeptical.

According to a survey by the Kaiser Family Foundation in early May, only one in five parents of a child under the age of 5 (18%) wanted to vaccinate them as soon as possible.

Like adults, children infected with Covid-19 can also suffer from long-term symptoms (Covid long). In rare cases, they can also develop severe cases of pediatric multisystem inflammatory syndrome.