Recommendation of WHO/EUL on risk management plan and pharmacovigilance plan for Sinovac COVID-19 vaccine


The WHO/EUL recommendations for Sinovac's COVID-19 vaccine, published on 28 June 2021, comment on the clinical aspects relating primarily to the risk management plan and the pharmacovigilance plan for this vaccine, which are summarized below.

Risk Management Plan:

 Important identified risks:

Include anaphylaxis and a warning that a minimum observation period of 15 minutes after vaccination is recommended, given the risk of potentially life-threatening anaphylactic/anaphylactoid reactions.

 Important potential risks:

  • The manufacturer considered the risk of vaccination-associated enhanced disease (VAED), including vaccine-associated enhanced respiratory disease (VAERD). WHO notes that there is a theoretical concern that vaccination against SARS-CoV-2 may be associated with enhanced severity of COVID-19 episodes which would manifest as VAED and can be potentially serious, lifethreatening, or fatal, and that require early detection, careful monitoring, and timely medical intervention.
  • Programmatic errors: WHO noted that it may be necessary to minimize this situation in advance under real use conditions. This will be monitored via routine pharmacovigilance activities and will be presented in each PBRER/PSUR.

 Missing information: WHO requested the inclusion of information on the following:

  • Use during pregnancy and while breastfeeding.
  • Use in immunocompromised patients, including HIV. This population was excluded from the clinical trials.
  • Use in people 60 years of age or older, without limiting it to individuals with chronic diseases, since insufficient data are available on safety and efficacy in this group.
  • Use in patients with comorbidities, e.g., chronic obstructive pulmonary disease (COPD), diabetes, chronic neurological disease, cardiovascular disorders.
  • Interaction with other vaccines, as well as interchangeability or sequential use with other vaccines.
  • Use in the pediatric populations <18 years of age.
  • Use in patients with autoimmune or inflammatory disorders. There is a theoretical concern that the vaccine may exacerbate their underlying disease.
  • Long-term safety: Additional activities will be needed to obtain such information.
  • Evaluation of the impact of the emergence of variants on vaccine efficacy/effectiveness and safety.

Pharmacovigilance plan: 

  • The conditions established to ensure proper traceability and monitoring of the cold chain should be specified.
  • Follow-up of adverse events of interest should take into account neurological disorders, reactogenicity following vaccination, and all serious adverse events.
  • The applicant is requested to monitor and evaluate the impact of these emerging SARS-CoV2 variants (such as alpha, beta, gamma, and delta, and others that may appear in the future) on the effectiveness of the Sinovac COVID-19 vaccine.


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