Updated SAGE/WHO recommendations for use of the Pfizer-BioNTech, Moderna, and Janssen COVID-19 vaccines
17/06/2021
On 15 June 2021, WHO's Strategic Advisory Group of Experts on Immunization (SAGE) reported that the interim recommendations for use of COVID-19 vaccines from Pfizer-BioNTech, Moderna, and Janssen had been updated, based on the latest relevant evidence. The main findings were as follows:
Pfizer-BioNTech:
- Indication: Indication for use was extended to individuals ages 12 and older. WHO recommends that countries consider vaccinating children ages 12 to 15 only when there is high vaccination coverage in high-priority groups.
- Considerations for postponing the second dose in settings with a limited supply of vaccines: Post-vaccination studies in countries that have implemented a longer interval between doses, along with additional immunological data, suggest that delaying the second dose of vaccine for up to 12 weeks in countries with a high incidence of COVID19 combined with severe vaccine shortages could be considered in order to achieve higher first-dose coverage in high-priority populations.
- Interchangeability of vaccines: Preliminary results from heterologous vaccine administration studies, in which the Pfizer-BioNTech vaccine was administered as a second dose, following an initial dose of the AstraZeneca vaccine, showed slightly increased, but acceptable levels of reactogenicity, with similar or higher immunogenicity, thus supporting use of a heterologous vaccine regimen.
- Precautions: A possible causal association of the vaccine with very rare cases of myocarditis in young men (ages 16 to 24) is being investigated.
- Pregnancy: Completed studies of reproductive toxicity and development in animals showed no harmful effects of the vaccine on pregnancy. Data from small studies have shown that mRNA COVID-19 vaccines are immunogenic in pregnant women, and that vaccine-elicited antibodies are transported into umbilical-cord blood and breast milk, suggesting possible neonatal as well as maternal protection. As data become available from additional studies currently being conducted, these recommendations will be updated.
- SARS-CoV-2 variants: Preliminary results indicate that after 2 doses of the PfizerBioNTech vaccine, effectiveness against symptomatic SARS-CoV-2 infection with the Beta variant (B.1,351) is 75.0% (95% CI 70.5%-78.9%); for the Delta variant (B.1,617.2), effectiveness was estimated to be 88% (95% CI 78.2%-93.2%), with 93% effectiveness (95% CI 90.4%-95.5%) against the Alpha variant (B.1.1.7).
- Storage temperature: The length of time that the undiluted vaccine can be kept between 2°C and 8°C was extended from the initially authorized five days to up to one month (31 days).
- Safety surveillance and monitoring: The Group of Experts recommends monitoring the following serious adverse events: myocarditis, thromboembolic events, thrombosis with thrombocytopenia syndrome (TTS), anaphylaxis and other severe allergic reactions, Bell's palsy, transverse myelitis, cases of multisystem inflammatory syndrome following vaccination, and cases of COVID-19 following vaccination that result in hospitalization or death.
Updated recommendations for the Pfizer-BioNTech vaccine are available at: https://www.who.int/publications/i/item/WHO-2019-nCoV-vaccines-SAGE_recommendationBNT162b2-2021.1
Moderna:
- Considerations for postponing the second dose in settings with a limited supply of vaccines: Post-vaccination studies in countries that have implemented a longer interval between doses, along with additional immunological data, suggest that delaying the second dose of vaccine for up to 12 weeks in countries with a high incidence of COVID12 combined with severe vaccine shortages could be considered in order to achieve higher first-dose coverage in high-priority populations.
- Precautions: A possible causal association of the vaccine with very rare cases of myocarditis in young men (ages 16 to 24) is being investigated.
- Pregnant and nursing women: The text was updated and harmonized with PfizerBioNTech's recommendations for the mRNA vaccine.
- SARS-CoV-2 variants: Preliminary results indicate some reduction in the neutralizing activity conferred by the vaccine against the Beta variant of concern (B.1.351), and a less marked reduction for the variants of interest -- Gamma (P1), Alpha (B.1.1.7), and Epsilon (B.1.429) (16). Effectiveness against the Delta variant (B.1.617.2) is still unknown.
- Safety surveillance and monitoring: The Group of Experts recommends monitoring the following serious adverse events: myocarditis, thromboembolic events, thrombosis with thrombocytopenia syndrome (TTS), anaphylaxis and other severe allergic reactions, Bell's palsy, transverse myelitis, cases of multisystem inflammatory syndrome following vaccination, and cases of COVID-19 following vaccination that result in hospitalization or death.
Updated SAGE recommendations for the Moderna vaccine are available at:
https://www.who.int/publications/i/item/interim-recommendations-for-use-of-the-moderna-mrna1273-vaccine-against-covid-19
Janssen:
- General characteristics of the vaccine: Results on the efficacy of the vaccine were incorporated in figures for hospitalizations after 28 days following administration of the vaccine. There are reports of deaths in the placebo group, with no reported deaths in the vaccinated group. There are also reports that vaccine efficacy is maintained in settings where the P2 and B1.351 variants are responsible for the majority of cases.
- Precautions: Information related to thrombosis with thrombocytopenia syndrome (TTS) and its possible association with the vaccine has been included. Recommendations are given on the importance of early identification of TTS, in order to initiate appropriate treatments. It should still be emphasized that the benefit of vaccination in protecting against COVID-19 outweighs the risks.
- Pregnant women: Women during pregnancy may have a higher incidence of thrombosis, thrombocytopenia, and bleeding, and although it is not known whether there is an increased risk of thrombosis with thrombocytopenia syndrome (TTS), WHO recommends the use of this vaccine in pregnant women only if the benefit of vaccination outweighs the potential risks.
- Safety surveillance and monitoring: The Group of Experts recommends monitoring the following serious adverse events: myocarditis, thrombosis with thrombocytopenia syndrome (TTS), anaphylaxis and other severe allergic reactions; cases of multisystem inflammatory syndrome following vaccination; cases of COVID-19 following vaccination that result in hospitalization or death; AEFI baseline rate (including thromboembolic events, cerebral venous sinus thrombosis, and TTS); maternal and neonatal outcomes; mortality in groups prioritized for vaccination; and incidence of TTS by WHO region, age, and sex.
Updated recommendations for the Janssen vaccine are available at: https://www.who.int/publications/i/item/WHO-2019-nCoV-vaccines-SAGE-recommendationAd26.COV2.S-2021.1