Scientists may have discovered a vaccine that can fight any strain of the virus and is safe for babies

Scientists at the University of California (USA) have revealed a new strategy for creating an RNA-based vaccine that is effective against any strain of the virus and is safe even for infants and people with weakened immune systems.

The vaccine, how it works and the demonstration of its effectiveness in mice are described in a paper published this Monday in the scientific journal Proceedings of the National Academy of Sciences, according to a statement from the University of California, Riverside (UCR).

“What I want to emphasize about this vaccination strategy is that it is broadly (…) applicable to any number of viruses, (…) effective against any variant of the virus and safe for a wide range of people. This could be the universal vaccine we have been looking for,” said Rong Hai, a virologist at UCR and author of the paper cited in the statement.

Each year, researchers try to predict which four strains of the flu virus are most likely to be dominant in the next flu season, and an updated vaccine should be taken annually.

The same thing happened with vaccines against SARS-CoV-2, the coronavirus that causes Covid-19, which were reformulated to target subvariants of the dominant strains in circulation.

By targeting a part of the viral genome that is common to all strains of the virus, the new strategy will eliminate the need to create different vaccines.

“Traditionally, vaccines contain a live, killed or modified version of the virus. The body’s immune system recognizes the virus protein and produces an immune response,” producing “T cells that attack the virus and stop it from spreading” and “memory B cells” that train the immune system to fight off future attacks.

It has now been revealed that the vaccine “uses a modified live version of the virus” but is “not dependent” on the aforementioned immune response, so it can be taken by children with nascent immune systems or immunocompromised people, but rather on small RNA. molecules that silence disease-causing genes.

“The host—human, mouse, whatever is infected—will produce small interfering RNAs as an immune response to the viral infection. These RNAi then kill the virus,” explained Shouwei Ding, professor of microbiology at UCR and lead author. document mentioned in the application.

Since viruses cause disease because they produce proteins that block the host’s RNAi response, creating a mutant virus that cannot produce the protein to suppress RNAi weakens the virus.

“It can reproduce itself to a certain extent, but then loses the battle against the host RNAi response,” Ding said, adding: “The virus weakened in this way can be used as a vaccine to strengthen our RNAi immune system.”

The new strategy was tested in mutant mice lacking T and B cells, and it was found that with one injection of the vaccine, mice were protected from a lethal dose of unmodified virus for at least 90 days (some studies suggest that nine days in rats is roughly equivalent to that in humans year). Even newborn mice produce small RNAi molecules, so the vaccine also protected them.

The University of California, Riverside has already received a US patent on this RNAi vaccine technology, and the researchers’ next step will be to create a flu vaccine to protect children.

“If we are successful, they will no longer be dependent on their mothers’ antibodies,” Dean said.

Scientists say the likelihood of the virus mutating to evade this vaccination strategy is still low.

“Viruses can mutate in areas that traditional vaccines do not target. However, in this case, the target of thousands of small RNAs is their entire genome. They can’t leave,” Hai said.

The researchers also believe that using a cut-and-paste strategy, they will be able to create a single vaccine for any type of virus.

“There are several well-known human pathogens, such as dengue fever and SARS. They all have similar viral functions,” so the new strategy “should be suitable for these viruses,” Dean said.