The European Medicines Agency’s (EMA) human medicines committee (CHMP) has started the first rolling review of a COVID-19 vaccine, which is being developed by AstraZeneca in collaboration with the University of Oxford.
A rolling review is a regulatory tool used by the EMA to speed up the assessment of a promising medicine or vaccine during a public health emergency. Normally, all data upon a medicine’s effectiveness, safety and quality, and all required documents must be submitted at the start of the evaluation in a formal application for marketing authorisation. In the case of a rolling review, the CHMP reviews the data as it becomes available from ongoing studies, before deciding that sufficient data is available, and that a formal application should be submitted by the company. The rolling review process has been used previously in the assessment of the COVID-19 medicine, Veklury (remdesivir).
Subject data collection
The start of the rolling review means the CHMP has begun evaluating the first batch of data on the vaccine, which comes from non-clinical (laboratory) data. This does not mean that a conclusion can be reached yet on the vaccine’s safety, and effectiveness, as much of the evidence is still to be submitted to the CHMP. The CHMP’s decision to start the rolling review of the vaccine is, however, based upon preliminary results from non-clinical and early clinical studies, suggesting the vaccine triggers the production of antibodies and T cells (cells of the immune system, the body’s natural defences) that target the virus.
Large-scale clinical trials involving several thousands of subjects are ongoing, and results will become available over the coming weeks and months. The results will provide information on how effective the vaccine is in protecting against COVID-19, and will be assessed in later rolling review cycles. All the available data on the safety of the vaccine emerging from these studies, as well as data on its quality, such as its ingredients and the way it is produced, will also be reviewed. The rolling review will continue until enough evidence is available to support a formal marketing authorisation application. While the overall review timeline cannot be forecast at present, the process should be shorter than a regular evaluation, due to the time gained during the rolling review.
How the vaccine is expected to work
The vaccine, known as COVID-19 Vaccine AstraZeneca, is expected to work by preparing the body to defend itself against infection with the coronavirus SARS-CoV-2. The COVID-19 virus uses proteins on its outer surface, called spike proteins, to enter the body’s cells and cause disease. COVID-19 Vaccine AstraZeneca is made up of another virus (of the adenovirus family) that has been modified to contain the gene for making the SARS-CoV-2 spike protein. The adenovirus cannot itself reproduce, and does not cause disease. Once given, the vaccine delivers the SARS-CoV-2 gene into cells within the body. The cells will then use the gene to produce the spike protein. The body’s immune system will then treat this spike protein as foreign, and produce natural defences − antibodies and T cells − against this protein. Immunised, in the event the body comes into contact with SARS-CoV-2, the immune system will recognise the virus, and attack it: antibodies and T cells will work together to kill the virus, prevent its entry into the body’s cells, as well as destroy infected cells, thus helping to protect against COVID-19.
Steps taken by the United Kingdom
Notwithstanding the rolling review, ministers are planning to change the law to allow a vaccination programme to begin before the end of the year, in the event UK regulators believe it to be safe, even before it is approved by the EMA, to which Britain is bound until January. On the 28 August 2020, the UK government published a consultation paper to consider changes to the Human Medicine Regulations 2012, which seeks consultation under 5 headings: (1) temporary authorisation of the supply of unlicensed products; (2) civil liability and immunity; (3) proposed expansion to the workforce eligible to administer vaccinations; (4) vaccine promotion; and (5) provisions for the wholesale dealing of vaccines.
On 3 September 2020, The Times reported that scientists working on COVID-19 Vaccine AstraZeneca hoped it could be approved by regulators before the start of next year, with some health officials estimating that every adult could receive a dose within six months. Government sources involved in making and distributing the vaccines told The Times that they expected a full programme, which would exclude children, could take six months or less after approval, and would probably be significantly quicker. Despite last week, the authors of a Royal Society report claimed it could take as long as a year before everyone who was eligible received the vaccine, health officials believe it can be done far faster irrespective of which vaccine is successful. With measures being taken by the EMA, and the United Kingdom government to fast track authorisation and manufacturing, a programme of vaccination seems expected sooner rather than later.
Source: EMA press office