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Source: United Kingdom – Executive Government & Departments

With a lot of recent focus on vaccines, here are some general comments from Dr Craig Hartford on how the safety of vaccines is assessed.

Dr Craig Hartford, Committee Member of the Faculty of Pharmaceutical Medicine’s Policy and Communications Group, said:

“Vaccines approved by the MHRA are safe and effective for use.

“Establishing the safety of a vaccine starts way back in the early research programs in which the vaccine is tested in vitro and in vivo to determine its safety profile before even beginning to test the vaccine in human volunteer clinical studies. This “pre-clinical” testing provides extensive information about the predicted safety of the vaccine in humans, and is conducted by scientists with advanced subject matter expertise in assessing and minimizing the potential toxic effects of a vaccine.

“Once the vaccine fulfills pre-clinical safety criteria that allow for its preliminary safe testing in humans, then only does the testing of the vaccine in humans start.

In “Phase 1” studies in humans the safety and tolerability of the vaccine is specifically focused on, yielding information about the early responses of our human bodies to the vaccine.  This allows the clinical investigators and the manufacturer to assess both common side effects as well to glean information about how the vaccine is acting inside our body, not only in terms of an immune response to the vaccine but also how all other systems in the body are responding to the vaccine. It also allows the vaccine study team to begin to assess what the right dose of the vaccine is likely to be so that any potential side effects are minimized.

“Only once this early testing in humans is completed, and the vaccine is shown to be well tolerated and safe in a small number of subjects, is the vaccine then allowed by the Regulator and manufacturer to be administered to a much bigger and broader population through what are known as Phase 2 and Phase 3 clinical studies. Here a broader spectrum of subjects participate in the studies. In these studies the vaccine safety is monitored not only by the manufacturer and by the clinical investigators but also by an independent data safety monitoring board, oversight by an independent ethics committee and indeed by regulators themselves. Vaccine manufacturers have dedicated safety professionals, i.e. people whose only role is to monitor the safety of the vaccines, assigned to the vaccine development team and they are specifically continuously monitoring the safety of the product during development. They also have safety teams who make decisions about the safety of the vaccine’s safety internally.

“Following the demonstration of safe use in Phase 3 clinical trials, the safety experts at the manufacturer produce a full clinical summary of safety and benefit-risk assessment and present that document to the regulator for review during the regulatory approval stage. This information along with all other sources of information about the vaccine are fully reviewed and considered by the regulator in arriving at a decision as to whether the vaccine is safe and effective to be administered to the public, i.e. in arriving at the decision that the vaccine has a positive benefit-risk profile.

“Furthermore, the close scrutiny of the safety of the product, continues well beyond the approval for use stage. Once the vaccine is made available to the public, reports from health care professionals and from patients about side effects are monitored daily. Each safety or side effect report is reviewed individually as well as cumulatively with all other side effect reports, also employing advanced computer methods to identify safety signals for a product.  If a safety signal is identified, that signal will be further evaluated in great detail by both the manufacturer as well as by the regulator to determine if the safety signal may be a potential risk to the public. If a potential risk is identified, and that risk is considered to be important, then that risk is minimized using a Risk Management Plan which is formally generated and implemented to carefully manage that risk. This includes additional safety monitoring  activities, such as actively exploring safety events that are considered to be of interest and conducting special Post-Approval Safety Studies.

“In addition, the manufacturer produces for the regulator a Periodic Benefit-Risk Evaluation Report about all aspects of the safety and efficacy of the vaccine, for regular scrutiny by the regulator. Vaccines safety is not only monitored in the UK but globally e.g., by WHO, and all that information where relevant is reported to the MHRA by the manufacturer for continuous safety assessment.

“Regarding monitoring the Safety of the Vaccine in the UK, it is worth mentioning here in particular the MHRA’s Yellow Card Scheme**:  The Yellow Card Scheme will be very important to helping monitor the safety of the Covid-19 vaccines, along with other safety monitoring systems and safety monitoring plans implemented by e.g. companies, the regulators, the WHO and other coordinating bodies. The MHRA have published a specific Coronavirus Yellow Card reporting site, reflecting the importance of this area and the importance of the reporting of vaccine side effects by both the public and HCPs.

“In summary, all medicines and vaccines can have some side effects, but these side effects are unusual, they are typically mild, transient and not serious, and serious side effects are rare. The benefits of the vaccine outweigh the risks and the safety of vaccines is very closely monitored and assessed. The COVID-19 Vaccine when approved for use in the UK by the MHRA is safe and effective for use in the public.

Declared interests

None received.

MIL OSI United Kingdom