Short-term immunity conferred by COVID-19BNT162b2 vaccination in adolescents and children

In a recent article posted on medRxiv* Preprint server, researchers have demonstrated short-term protection provided by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) BNT162b2 vaccination in adolescents and children.

Background

The Coronavirus Disease 2019 (COVID-19) Pfizer-BioNTech (BNT162b2) vaccine is less efficient against the SARS-CoV-2 Omicron variant than the Delta and other variants. In addition, the actual efficacy of the BNT162b2 vaccine against Omicron infections in children and adolescents is limited.

Shortly before the outbreak of SARS-CoV-2 Omicron, Israel approved a BNT162b2 double vaccination for children and a third BNT162b2 shot for adolescents. BNT162b2 vaccination was approved in Israel on June 2, 2021 for adolescents aged 12 to 15 years, and booster vaccination was given to those who received a second vaccination at least 5 months ago in 2021 8. Approved on the 29th of March. Since November 23, 2021, children aged 5 to 11 have been vaccinated twice with BNT162b2 using one-third of the amount provided to children aged 12 and over. However, the impact of these vaccinations on the observed SARS-CoV-2 infection rate in Omicrons in these populations remains unclear.

About research

In the current study, researchers analyzed data from Israel to investigate. Effectiveness of A double-dose BNT162b2 schedule for children aged 5-11 and booster shots for adolescents aged 12-15. .. They state that reliable estimates of efficacy after January 8, 2022 are difficult to obtain due to significant policy changes in COVID-19 testing, contact isolation, and quarantine at schools. I did.

Scientists have analyzed data from the Israeli Ministry of Health’s database, including information on all vaccinations and tests performed in Israel. The study cohort includes children (5-10 years old) and adolescents (12-15) who have been vaccinated with the COVID-19 vaccine or at least one state-regulated vaccine. antigen Alternatively, a polymerase chain reaction (PCR) test prior to December 1, 2021. The team omitted the 11-year-old age group because the current data only includes age and the vaccination eligibility dates differ between 11 and 12 years old.

Researchers have found that children aged 5 to 10 years 14 to 35 days after receiving a second dose in the internal control cohort 3 to 7 days after receiving the first shot while vaccination is still taking place. The confirmed SARS-CoV-2 infection rate in was assessed ineffective. Similarly, they compared the confirmed COVID-19 rates in adolescents aged 12 to 15 years 14 to 60 days after receiving a booster shot with a control cohort of adolescents 3 to 7 days after receiving a booster dose. Did. The authors used Poisson regression to control gender, age, calendar week, exposure, and socioeconomic levels.

Results and conclusions

Overall, study results showed that COVID-19 BNT162b2 vaccination provided nearly a two-fold improvement in immunity to SARS-CoV-2 infection in children aged 5 to 10 years. The age category was 2.3-fold lower in the second-dose cohort compared to the internal control population.

In addition, current analysis found that recent adolescent BNT162b2 booster doses reduced SARS-CoV-2 infection by 3-4 fold compared to internal controls. Specifically, the third dose reduced the confirmed adolescent COVID-19 rate over 3.3 hours.

The authors found that different testing habits did not explain the reduced SARS-CoV-2 infection rates found in the vaccinated group compared to the unvaccinated group. Did. In all age categories, unvaccinated cohorts are tested less frequently than vaccinated groups and may underestimate the expected protection compared to unvaccinated individuals. It means that there is sex.

The unvaccinated cohort had a lower test rate than the vaccinated group, but internal control subjects showed slightly higher test rates than the second vaccinated group in the 5-10 year range. This can contribute to overestimating vaccine protection. Internal control subjects had lower test rates than the booster group in the vaccinated range of 12 to 15 years. This shows that booster shots provide better protection than expected in this study.

In summary, the current study shows an assessment of the transient protection of the COVID-19BNT162b2 vaccine against SARS-CoV-2 infection confirmed in adolescents and children. Recent two doses of BNT162b2 vaccine in children and the latest booster immunization in adolescents have reduced the risk of confirmed SARS-CoV-2 infection compared to the corresponding internal control cohort. The authors show how long this protection lasts, and how well from the results of other COVID-19, including long-COVID and pediatric inflammatory multisystem syndrome, which are temporarily associated with SARS-CoV-2 (PIMS-TS). He said future research is needed to decide whether to protect.

*Important Notices

medRxiv publishes unpeer-reviewed preliminary scientific reports and should not be considered definitive, guide clinical / health-related behaviors, or be treated as established information.