Covid-19, all the doubts about the new vaccine. Efficacy, shelf life, safety, and storage

Are we there yet? Are we at a real turning point with the Covid-19 vaccine, or do doubts only allow us cautious hopes? The news about vaccines to prevent Covid-19 is a pure injection of confidence, capable of improving our mood but also sending stock markets soaring, which are beginning to bet on a return to normality . And it's precisely being able to return to everything that was normal before February and is no longer so now that warms our hearts the most.

COVID-19 VACCINE QUESTIONS

But hopes are accompanied by doubts . These are also fueled by the scientific community, as in the case of the skepticism expressed by Professor Andrea Crisanti, who was censured by the majority of his colleagues. And aside from the squabbles among experts, Italians themselves have doubts: nearly one in two, according to research by the EngageMind Hub at the Catholic University of Milan.

COVID-19: DOUBTS ABOUT THE VACCINE

This time, people's doubts aren't based on ideological levers, as is the case with the anti-vaxxers ' positions , but on some fundamental, unresolved questions even by those who are ahead in the race for a vaccine. Let's look at the most important ones.

A provisional verdict. So far, over 130 people have been vaccinated in the trial, including those in Phase 3. This is a lot, considering that vaccine trials traditionally enroll between 300 and 3000 people. However, the trial's verdict is still provisional, as it only tells us whether people have been protected from viral infection, not whether the vaccine prevents severe disease or death. If only 10 percent of vaccinated people remain vulnerable because they have contracted the virus, there could be many sick people and deaths. And there's only one way to move from a provisional to a definitive verdict: administering the vaccine to a large population. With the possibility, which cannot be ruled out, that in the event of inconsequential results, the vaccine will be withdrawn.

Real-world efficacy. This is also an open question: the vaccine's efficacy, once it's been released for sale, distributed, and used, is significantly lower than what was found in clinical trials. Why this difference? The answer lies in the fact that, in general, the tests were conducted on young people (only Moderna has said it also conducted them on people over 65), and vaccines may not work well in older people.

Safety. It's true: the only symptoms observed in those tested are not serious. Fatigue, muscle aches, joint pain, headache, and fever (high between 39 and 40 degrees Celsius in only 2 percent of cases). But the Covid-19 vaccine uses the virus's messenger RNA, i.e., the viral genetic material, to induce an immune response, whereas vaccines typically use attenuated viruses or viral proteins. No vaccine of this type has yet been approved, so there could be some surprises.

Those previously infected. Another concern: the test results exclude people who have been previously infected. A widespread vaccine, which will reach a large portion of the population, will inevitably also be administered to those who have had the disease. And we also need to know the effects it will have on them. Currently, this is unknown.

How long will the effect last? This is a question to which science, for now, has provided no answer. The hope is for robust cellular immunity, even in the face of genetic mutations of the virus. The most likely, and perhaps most desirable, hypothesis is that the vaccination should be repeated periodically. Perhaps annually, as with the flu vaccine. But the idea that the vaccine can eradicate COVID-19 once and for all is truly only a hope.

Vaccine storage. In any case, the COVID-19 vaccine must be stored at very low temperatures. This can be problematic, as the World Health Organization (WHO) also points out. This is also due to the fact that it requires two doses.

Lack of transparency in communications. Until now, companies have only communicated test results through media reports, not through scientific articles, which scientists have the opportunity to conduct all the necessary analysis and verification. And the announcements have been accompanied by a truly unsavory practice: stock sales, at a significant profit, by company CEOs claiming they have the vaccine.

COVID-19 VACCINES

The best news recently has come from Pfizer/Biontech , Moderna , and AstraZeneca with Italy's IRBM. The pharmaceutical giants have announced that their vaccines have an efficacy rate between 70 and 95 percent . However, at least 239 vaccines have been developed worldwide, and 39 of these have reached the clinical trial phase . The first doses will most likely arrive in Italy at the beginning of 2021, and it will be important not to be caught unprepared: organizing a large-scale vaccination campaign will be no easy feat. In Spain, a commission is already ready and will make public the plan developed by Madrid in the coming days. In Italy, however, the matter (yet another) has been entrusted to Super Commissioner Domenico Arcuri , who, however, has not yet made any pronouncements on the path Italy will take.

PFIZER BIONTECH VACCINE

Regarding the Pfizer/BioNTech vaccine, the experimental phase has completed Phase 3 testing on 43.500 volunteers. In 95% of cases, the vaccine proved effective in preventing the onset of the disease. Furthermore, only a few side effects were recorded in rare cases, which were mild or moderate in intensity and resolved quickly. Before distribution begins, this vaccine, like all the others, will have to await authorization from the respective drug agencies . But Professor Ugur Sahin , co-founder of BioNTech, is convinced that it will soon be possible to begin shipping the first doses and that, thanks to the vaccines, normal life will be possible starting next winter . The only real critical issue with this vaccine is its storage: doses can only remain at room temperature for a few days and must be stored in special cold rooms capable of reaching temperatures of -70-80 degrees Celsius.

MODERN VACCINE

This vaccine, like the one developed by Moderna, uses an innovative technology that consists of protecting a strip of genetic material, messenger RNA (mRNA). The serum's goal is to train the immune system to recognize and block the coronavirus by preventing it from exploiting specific proteins it uses to bind to human cells. To be effective, both vaccines require a double administration, which is why careful and timely distribution planning must be organized on a large scale and down to the smallest detail.

CORONAVIRUS VACCINES

In addition to these two vaccines, of the 39 currently being tested , about ten have begun Phase III trials and are now nearing the conclusion of this crucial stage. Five are produced by companies based in Europe or the United States, four are produced by Chinese companies, and one is the work of the Gamaleya Institute in Moscow. These products differ greatly in terms of biological characteristics and development status, but it is likely that several of them could prove effective.

VACCINE: ITALIANS' DISFIDENCE

In short, there is reason to be cautiously optimistic, even if, according to polls, many in Italy are skeptical about the vaccine. According to Ipsos , in fact, as many as one in six Italians will refuse to get vaccinated. Specifically, 16% say they will not do so if it becomes available in 2021, and 42% will wait to determine its effectiveness. These doubts are legitimate up to a point, especially considering that vaccination is not a choice that affects only the individual. The vaccine is important for those who receive it, but also, if not especially, for those who , immunocompromised, would like to receive it but are unable to.