Swissmedic is reviewing the authorisation extension for a third dose of the COVID-19 vaccines from Pfizer

Ref: Swissmedic

Last week, the pharmaceutical companies Moderna and Pfizer submitted applications to Swissmedic, the Swiss Agency for Therapeutic Products, requesting a modification of the existing dosage recommendations for their COVID-19 vaccines. Swissmedic is examining the submitted data in the rolling review process.

The COVID-19 vaccines from Moderna (Spikevax) and Pfizer/Biontech (Comirnaty®) are currently authorised in Switzerland for those aged 12 and over. Both vaccines are administered in two doses.

Swissmedic is reviewing the submitted clinical data on the third vaccine doses ("boosters") for safety and efficacy, and checking whether the submitted data are sufficient for extending the indication accordingly. Swissmedic prioritises all applications connected with the COVID-19 pandemic, without compromising on the content reviews. When a decision can be made on the authorisation variations will depend on the submitted data and the results of clinical trials.

A "booster vaccination" is a further dose of vaccine administered after a certain period to fully vaccinated people with a basic level of immunisation in order to boost the immunological memory. Booster vaccinations would be indicated as soon as the protection after complete basic immunisation is no longer sufficient for preventing severe cases of COVID-19.

Current clinical data for the mRNA vaccines used in Switzerland to date, as well as findings from observational studies, have shown that lasting protection against severe cases of the illness is afforded with two administered doses. Therefore, according to recommendations issued by the Federal Commission for Vaccination (FCV), there is no acute need at present for general booster vaccinations in Switzerland.

The protection resulting from COVID-19 vaccination against infection or mild symptomatic disease is achieved by means of neutralising antibodies located in the blood or the mucous membranes of the respiratory tract. In the event of any subsequent contact with the pathogen, the latter is then recognised, thereby averting an outbreak of the illness or a severe case of the disease.

The amount of these antibodies slowly decreases following basic immunisation with two vaccine doses. Consequently, the protection against asymptomatic or mild infection/illness also declines, although the protection against serious cases of the disease, including hospitalisations, is maintained for a longer period. This is because complete vaccination results in the formation not only of antibodies, but also memory B cells and T cells, which basically afford protection against serious illness by being reactivated after contact with the virus and secreting large amounts of antibodies which, in turn, fight the pathogen quickly and efficiently.