The US has taken an important step toward a future in which vaccinations can be obtained simply by swallowing a pill containing bacteria. A team of researchers from the University of Cincinnati, led by Associate Professor Nalinikan Kotagiri, has developed probiotic bacteria that can not only stimulate the immune system but also directly fight viruses such as SARS-CoV-2. According to the authors, this development could become a universal tool for fighting viruses, including HIV.
The innovation is based on the E. coli Nissle 1917 strain, long known worldwide as a safe probiotic. In the laboratory, the bacteria were “reprogrammed”: now they are capable of producing viral proteins or special therapeutic nanobodies, and then independently pack these substances into microscopic bubbles — outer membrane vesicles (OMVs). Entering the body through the intestines, these vesicles act as autonomous delivery microsystems — they reach the mucous membranes or even the lungs, where they release their “antiviral cargo.”
The first experiments have already yielded promising results. An oral vaccine based on such bacteria stimulates an immune response similar to that caused by an intramuscular injection of an mRNA vaccine. However, its advantage lies in its ability to activate mucosal immunity, which plays a key role in fighting viruses that enter the respiratory or digestive tract. This is also critically important in the fight against HIV, which is also capable of penetrating mucous membranes.
Even more interesting results were obtained from experiments with “therapeutic” versions of bacteria. They produce nanobodies — ultra-small fragments of antibodies that neutralize the SARS-CoV-2 virus. Researchers have proven that OMVs with these nanobodies not only enter the bloodstream but also reach the lungs, where they effectively neutralize the virus in laboratory conditions. The bacteria can be swallowed repeatedly, which provides continuous therapy, as the bacteria remain active in the intestine for a long time, releasing therapeutic molecules.
In the future, scientists plan to adapt the system to other viruses — from influenza to norovirus. There are particularly high hopes for HIV, as immunity at the mucosal level is one of the keys to containing the infection. The versatility of the platform allows several functions to be combined in one probiotic — vaccine and therapeutic — and thus it will be possible to create a new generation of “smart pills.”
This approach has many advantages: no injections, no need for cold storage, and easy delivery to any corner of the world. In addition, the use of an already known safe strain of bacteria greatly simplifies the path to clinical trials. If human trials confirm the effectiveness of this technology, the world will gain a fundamentally new weapon against viral epidemics.
Remember, researchers in Australia made a significant breakthrough in HIV research using mRNA delivery technology — the same technology that underpins COVID-19 vaccines. However, instead of preventing infection, they directed it toward bringing the virus out of its latent state for potential treatment.