Coronavirus vaccine, who is the sick volunteer (and what is an adverse reaction)

All clinical trials for the coronavirus vaccine developed by the Swedish-British pharmaceutical company AstraZeneca in collaboration with the University of Oxford and Irbm (an Italian biotechnology company founded in Pomezia), after one of the 50,000 participating volunteers had a “suspected adverse reaction”.

The AstraZeneca-Oxford University vaccine is considered a strong competitor among the dozens in development globally. It was hoped that this vaccine could be one of the first to hit the market, after the success of phase 1 and 2 trials. But no. Now, after this slowdown in phase three of experimentation, we risk months of delay.

Vaccine against the coronavirus, the sick volunteer and the adverse reaction

The volunteer who fell ill is an English woman, as revealed by AstraZeneca CEO Pascal Soriot. But which one is adverse reaction and what happened in detail? An “adverse event” is a disorder that can appear after vaccination. These are usually minor problems. On the other hand, when more serious problems arise, it is necessary to stop the administration immediately to initiate in-depth investigations: all procedures are followed and evaluated by a committee of independent experts and are controlled by the regulatory authorities who must give (or not) final authorization.

If the adverse reaction is related to a cause other than the vaccine, phase three experimental tests can be restarted quickly, within a few days. Otherwise, if it was the vaccine that caused the adverse reaction, the slowdown can be long and last six to seven months.

In the case of the Covid vaccine AstraZeneca-Oxford University -of which the European Union has already reserved 400 million doses- at the moment it is not known if the vaccine or another cause caused the adverse event. The nature of the adverse reaction and when it occurred is still unknown. Some indiscretions speak of a “transverse myelitis”, an inflammation of the spinal nervous system whose symptoms can be expressed in the extremities with pain and loss of sensation. But there are no certainties: in the case of the English volunteer, the diagnosis is not definitive. That is why extensive research is needed to dig deeper and understand.

An AstraZeneca spokesperson described the pause as “a routine action that occurs whenever there is a possible unexplained reaction to one of the tests” that allows time to “investigate and ensure that the integrity of the testing process is maintained at the same time.” . The spokesperson also said the company is “working to expedite the review of the one-time event to minimize any potential impact on processing time.”

Despite the setback from the volunteer’s inexplicable reaction, according to Astrazeneca CEO Pascal Soriot, the results of the trial phase of the vaccine being studied at Oxford should still be available by the end of the year. Soriot added that it is very common for an experimentation process to be temporarily suspended, with the difference that right now everyone is watching.

Stop the Covid vaccine, what happens now (between alternatives and necessary postponements)