tetano
Editor, Senior Moderator
Clin Infect Dis
. 2022 Dec 9;ciac315.
doi: 10.1093/cid/ciac315. Online ahead of print.
Waning Effectiveness of the BNT162b2 Vaccine Against Infection in Adolescents in Israel
Ottavia Prunas[SUP] 1 [/SUP], Daniel M Weinberger[SUP] 1 [/SUP], Virginia E Pitzer[SUP] 1 [/SUP], Sivan Gazit[SUP] 2 3 [/SUP], Tal Patalon[SUP] 2 3 [/SUP]
Affiliations
Abstract
Background: The short-term effectiveness of a 2-dose regimen of the BioNTech/Pfizer BNT162b2 vaccine for adolescents has been demonstrated. However, little is known about the long-term effectiveness in this age group. It is known, however, that waning of vaccine-induced immunity against infection in adult populations is evident within a few months.
Methods: Leveraging the database of Maccabi Healthcare Services (MHS), we conducted a matched case-control design for evaluating the association between time since vaccination and the incidence of infections, where 2 outcomes were evaluated: documented SARS-CoV-2 infection (regardless of symptoms) and symptomatic infection (COVID-19). Cases were defined as individuals aged 12-16 with a positive polymerase chain reaction (PCR) test occurring between 15 June and 8 December 2021, when the Delta variant was dominant in Israel. Controls were adolescents who had not tested positive previously.
Results: We estimated a peak vaccine effectiveness between 2 weeks and 3 months following receipt of the second dose, with 85% (95% confidence interval [CI]: 84-86%) and 90% (95% CI: 89-91%) effectiveness against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19), respectively. However, in line with findings for adults, waning effectiveness was evident. Long-term protection was reduced to 73% (95% CI: 68-77%) against infection and 79% (95% CI: 73-83%) against COVID-19 3-5 months after the second dose and waned to 53% (95% CI: 46-60%) against infection and 66% (95% CI: 59-72%) against COVID-19 after 5 months.
Conclusions: Although vaccine-induced protection against both infection and COVID-19 continues over time in adolescents, the protection wanes with time since vaccination, starting 3 months after inoculation and continuing for more than 5 months.
Keywords: COVID-19 vaccine; SARS-CoV-2; waning of vaccine-induced immunity.
. 2022 Dec 9;ciac315.
doi: 10.1093/cid/ciac315. Online ahead of print.
Waning Effectiveness of the BNT162b2 Vaccine Against Infection in Adolescents in Israel
Ottavia Prunas[SUP] 1 [/SUP], Daniel M Weinberger[SUP] 1 [/SUP], Virginia E Pitzer[SUP] 1 [/SUP], Sivan Gazit[SUP] 2 3 [/SUP], Tal Patalon[SUP] 2 3 [/SUP]
Affiliations
- PMID: 36484301
- DOI: 10.1093/cid/ciac315
Abstract
Background: The short-term effectiveness of a 2-dose regimen of the BioNTech/Pfizer BNT162b2 vaccine for adolescents has been demonstrated. However, little is known about the long-term effectiveness in this age group. It is known, however, that waning of vaccine-induced immunity against infection in adult populations is evident within a few months.
Methods: Leveraging the database of Maccabi Healthcare Services (MHS), we conducted a matched case-control design for evaluating the association between time since vaccination and the incidence of infections, where 2 outcomes were evaluated: documented SARS-CoV-2 infection (regardless of symptoms) and symptomatic infection (COVID-19). Cases were defined as individuals aged 12-16 with a positive polymerase chain reaction (PCR) test occurring between 15 June and 8 December 2021, when the Delta variant was dominant in Israel. Controls were adolescents who had not tested positive previously.
Results: We estimated a peak vaccine effectiveness between 2 weeks and 3 months following receipt of the second dose, with 85% (95% confidence interval [CI]: 84-86%) and 90% (95% CI: 89-91%) effectiveness against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19), respectively. However, in line with findings for adults, waning effectiveness was evident. Long-term protection was reduced to 73% (95% CI: 68-77%) against infection and 79% (95% CI: 73-83%) against COVID-19 3-5 months after the second dose and waned to 53% (95% CI: 46-60%) against infection and 66% (95% CI: 59-72%) against COVID-19 after 5 months.
Conclusions: Although vaccine-induced protection against both infection and COVID-19 continues over time in adolescents, the protection wanes with time since vaccination, starting 3 months after inoculation and continuing for more than 5 months.
Keywords: COVID-19 vaccine; SARS-CoV-2; waning of vaccine-induced immunity.