The Oxford vaccine against the new coronavirus also seems safe

The University of Oxford has concluded phases 1 and 2 of the clinical trial of the vaccine based on an adenovirus: the results are positive and phase 3 will begin soon on thousands of people

(photo: Getty Images) A another vaccine against the new coronavirus passes safety tests. The Lancet magazine has just published the results of phases 1 and 2 of the clinical trial of the so-called Oxford vaccine, the one in which the Italian biotech Irbm also participated and already booked also by the Italian government. The overseas candidate promises well: the side effects encountered are not serious and almost all the volunteers have developed neutralizing antibodies and specific T cells. However, the researchers themselves point out, the tests are not over: the population sample must be enlarged and data collected over the long term to understand whether the immunity conferred by the vaccine is sufficient to protect against infection and for how long.

The Oxford vaccine

ChAdOx1 nCoV-19 is the candidate vaccine against Sars-Cov-2 developed by the University of Oxford in record time. The scientists used an adenovirus (from the family of those that cause common colds) modified in the laboratory to express the spike protein of the new coronavirus and to prevent it from replicating in the host. Its administration should teach our immune system to recognize the foreign spike protein and to react quickly if the real virus tries to infect us.

The technology used is similar to that used for other vaccine candidates, such as the Chinese one developed by CanSino Biologics or the Russian one (of which little is known).

The study

As described on the Lancet , the british researchers conducted a phase 1/2 trial was a blinded, randomized, controlled trial in 5 centers in the United Kingdom. The volunteers involved were in total 1,077 , all healthy adults between 18 and 55 years who have never contract Sars-Cov-2 above.

The participants were divided into two groups randomly : half received the experimental vaccine, the other half a dose of MenACWY (a vaccine antimeningococcico conjugate), for intramuscular injection.

10 participants, then, have also received a second dose of ChAdOx1 nCoV-19 after 28 days .

The results

To the researchers, the vaccine anti-coronavirus has an acceptable safety profile , which makes it suitable to continue in the trial. More than half of the participants showed side effects such as headache, chills, muscle aches and fever, but so minor that they can be well controlled with paracetamol.

with regard To the immune response, the vaccine candidate stimulated the production of specific T cells and IgG antibodies (those that form the immune memory), which reached the peak, respectively, after 14 and 28 days after the first injection. In 10 people who have received a second dose of the vaccine, the immune response is further enhanced .

This is very positive news. A huge well done to our brilliant, world-leading scientists & researchers at @UniofOxford .

There are no guarantees, we're not there yet & further trials will be necessary – but this is an important step in the right direction. https://t.co/PRUTu8rlPF

— Boris Johnson #StayAlert (@BorisJohnson) July 20, 2020



scientists have found that the presence of neutralizing antibodies against the new coronavirus in 91% of the samples tested (35) after a single dose of vaccine, and in 100% of samples of the volunteers who have also received the second dose .

“ we Hope that this means that the immune system will remember the virus so that the vaccine can protect people for a long time,” said Andrew Pollard, lead author of the study in Oxford. “However, we need more research before we can confirm that the vaccine effectively protects from infection by SARS-CoV-2, and for how long does any protection.”

what's missing

These data according to the authors of the research are very promising : a good starting point for confidence in the safety and efficacy of the vaccine. However, we must not be ahead of times , already – let's remember – terribly accelerated compared to the standards of the pre pandemic.

The safety data need to be updated on the basis of the results obtained by broadening the population sample to which you will be given the vaccine, especially with regard to the effect of the second administration (from 10 persons there are very few of).

Information on efficacy , instead, you will have in the medium and long term. In particular, some questions still remain without answer: the immunity conferred by the vaccine is enough to prevent infection? And if yes, for how long ?

For this phase 3 trial already announced plans to involve large-scale of people between the United Kingdom , Brazil, and south Africa , while in the United States the program is to test the vaccine starting from the end of the summer, about 30 thousand people .