The safety and effectiveness of young people's vaccination exceeds 90%, the results of Phase 3 of Moderna's new crown vaccine are published

Today, the "New England Journal of Medicine" published the results of an important clinical trial of the new crown vaccine mRNA-1273 (developed by Moderna) for adolescent vaccination
.

This placebo-controlled trial covering more than 3700 people showed that the safety of two doses of mRNA-1273 vaccine for adolescents aged 12-17 years is acceptable, and the response after vaccination is similar to that of other age groups; the immune response is similar to that of young adults (18-25 years old) Similarly, high levels of neutralizing antibodies are produced, and two doses of mRNA-1273 vaccine can also effectively prevent the new coronavirus disease (COVID-19) in adolescents

Screenshot source: The New England Journal of Medicine

This phase 2-3 trial randomly assigned 3732 healthy adolescents (12 to 17 years old) 2:1 to receive two doses of mRNA-1273 vaccine (100 μg each time) or placebo, with an interval of 28 days
.

The average age of the subjects was 14.

The main goal of the trial is to evaluate the safety of mRNA-1273 in adolescents and compare the immune response of adolescents with the data of young adults (18-25 years old) in the previous phase 3 trial of COVE
.

The data published this time are interim analysis data.

The results show that the mRNA-1273 vaccine has acceptable safety in adolescents
.

In the mRNA-1273 vaccine group, the most common adverse reactions after the first or second dose were injection site pain (93.
1% and 92.
4%, respectively), headache (44.
6% and 70.
2%, respectively) and fatigue (respectively) Are 47.
9% and 67.
8%)
.

In the placebo group, the most common adverse reactions after the first or second injection were pain at the injection site (34.
8% or 30.
3%, respectively), headache (38.
5% and 30.
2%, respectively) and fatigue (36.
6, respectively) % And 28.
9%)
.

No serious adverse events related to mRNA-1273 vaccine or placebo were found
.

The local or systemic reaction caused by the vaccine usually lasts for an average of about 4 days
.

Overall, the incidence of adverse reactions in subjects aged 12-15 and 16-17 were roughly similar
.

In the mRNA-1273 group, the incidence of local or systemic adverse reactions in adolescent subjects and young adults was roughly similar

The two doses of mRNA-1273 vaccine elicited immune responses in adolescents similar to those in young adults and reached the standard of non-inferiority
.

After adolescent subjects received two doses of mRNA-1273 vaccine, the titers of pseudovirus neutralizing antibodies in their bodies were 1.

The secondary objectives of the trial include the effectiveness of the mRNA-1273 vaccine in preventing COVID-19 or asymptomatic infections
.

According to the strict definition of COVID-19 by the US Centers for Disease Control and Prevention (nucleic acid positive + at least two systemic symptoms or at least one respiratory symptom), in the mRNA-1273 group, no COVID-19 cases occurred 14 days after the second dose, placebo Four cases occurred in the group, and the effectiveness of two doses of mRNA-1273 to prevent COVID-19 was 100%
.

However, the paper pointed out that due to the low incidence of COVID-19, this data is difficult to accurately assess

For example, according to the more relaxed definition of COVID-19 by the US Centers for Disease Control and Prevention (nucleic acid positive + at least one systemic or respiratory symptom), 14 days after the second dose of vaccination, the effectiveness of the mRNA-1273 vaccine to prevent COVID-19 is 93.
3%; The effectiveness of one dose 14 days after vaccination is 92.
7%
.

14 days after the second dose of vaccination, the effectiveness of the mRNA-1273 vaccine in preventing infection is estimated to be 55.
7%, and the effectiveness in preventing asymptomatic infection is estimated to be 39.
2%
.

The research team also pointed out that the study has certain limitations
.

In this trial, efficacy analysis is the secondary goal, because the incidence of young people infected with the new coronavirus is lower than that of adults, and the symptoms are also milder

The paper concluded that the results of the interim analysis of this trial showed that the overall benefits of mRNA-1273 in adolescents outweigh the risks.

Reference

[1] Kashif Ali, et al.