In times of pandemic, talking about a universal vaccine, which protects against coronaviruses capable of infecting humans (there are 7 known strains), is equivalent to talking about a rain of bread in times of famine: it would be a boon, not from Heaven, but from Science. Some experts discuss this possibility in an article in The Conversation, wondering if the hypothesis is real, or if it is just a magnificent and unattainable utopia.
Promising vaccines. If we were to look at what we have achieved so far, we could be discouraged: for years we have been trying to develop a vaccine that permanently protects us from seasonal flu, but we have not yet succeeded. However, the incredible scientific turbo of the last year bodes well: mRNA vaccines have changed the cards, paving the way for a new technology that could facilitate the creation of a universal vaccine. “According to experts, there are already several promising universal vaccine candidates,” the Conversation reads, “and it is even possible that within twelve months someone will be ready to be administered to humans.”
Time and money. The Coalition for Epidemic Preparedness Innovations (CEPI) has allocated $ 200 million for the development of a universal vaccine that offers protection from any coronavirus (even regardless of variants), and reduces the need for periodic adaptation. According to Richard Hatchett, CEO of CEPI, “a universal vaccine would be a holy grail, but its development could take years of investment.” According to the expert, the most promising strategy is to search the weaknesses common to all coronaviruses, to be hit for develop an immune response that protects us.
Three candidates. In fact, several already exist protovaccini promising, some of which have shown good results in animal experiments.
The first approach is described by Barton Haynes, immunologist at Duke University (USA): the idea is to attach “bits” of RBD to a protein nanoparticle (receptor-binding domain, or specific region of binding with the receptor, part that binds to the host cell ACE2 receptor) of the spike protein belonging to different coronaviruses. This particle would form the core of the vaccine. Early monkey experiments look promising: the protovaccine appears to block not only SARS-CoV-2 and its variants, but also SARS-CoV-1 (the SARS coronavirus) and other types of coronaviruses that could make the leap especially in the future.
Another potential vaccine is that developed by a team from the California Institute of Technology (Caltech): the approach is similar to that of Duke University, and involves the use of a nanoparticle to which “attach” bits of spike protein. Here, too, the results of the tests carried out on mice are promising, showing that a single dose of the vaccine could knock out several animal and human coronaviruses.
Fighting all coronaviruses. Even the University of Cambridge is studying a way to fight all coronaviruses with a single vaccine, and it does so with an innovative method that uses a DNA construct (an artificially created segment of DNA): «once the antigen has been identified, the small section of genetic code that the virus uses to reproduce the essential parts of its structure is inserted into a vector, ”explain the scholars. Our immune system, once it receives the information from the vector, recognizes the antigen and programs its response. In animal experiments this method has yielded excellent results, providing protection against various sarbecoviruses (subgenus of coronavirus to which SARS-CoV-2 belongs) and other coronaviruses.
In short, the path towards a universal vaccine is long, but not impossible to follow: we must have faith in science and remember that, up to a year and a half ago, the idea of an effective and safe vaccine ready in a year was considered crazy. from most, and today in Italy the vaccinated are almost 40 million.