An inexpensive vaccine against the Sars-CoV-2 coronavirus is as promising as common but more expensive mRNA vaccines against the pathogen. This is reported by a team led by Austrian virologists Florian Krammer and Father Palese of the Icahn School of Medicine at Mount Sinai Hospital in New York in the journal Science Translational Medicine. As part of a phase I clinical study conducted in Thailand, trial participants developed a similarly high level of antibodies after administration of the new “NDV-HXP-S” vector vaccine as people who received the Biontech-Pfizer vaccine.
Background: Several vaccines have been developed since the beginning of the pandemic. In Western countries, Pfizer/Biontech is common. The US government is currently paying about $30 per dose to the US drugmaker and its German partner Biontech. Pfizer is considering raising the price to between $110 and $130 per dose in the future, as its current purchase agreement with the US government is about to expire, CEO Angela Lukin recently announced. “Rich countries can afford and provide the technical requirements, low-wage countries cannot”, Peter Palese commented on the developments in an interview with the “Wiener Zeitung”.
The New York team led by Palese, Krammer and Adolfo Garcia-Sastre’s group began to develop a vaccine that would cost less than a dollar per dose at the beginning of the Covid-19 pandemic. The researchers chose a classic route in vaccine development and production. “NDV-HXP-S” is a vaccine in which a version of the Sars-CoV-2 spike protein is brought into the body via another virus (called a vector). In most cases, these pieces of DNA are wrapped in a modified adenovirus, which is harmless to humans, so that the blueprint enters the body’s cells and they fight the infection. However, adenoviruses “would need to grow in human cells, which complicates things, and some people are immune to them,” explains Palese.
Production in chicken eggs
The research team uses the Newcastle disease (NDV) pathogen in chickens, which causes a form of bird flu but is harmless to humans. The Newcastle pathogen introduces the Sars-CoV-2 surface protein gene into the body.
According to the researchers, the vaccine, which can also be administered through the nose, has been tested for some time in the US, Mexico, Vietnam, Thailand and Brazil. Tests are being carried out with two variants: a live vaccine and another with modified and inactivated NDV viruses. In the phase I study in Thailand mentioned in the study, 210 volunteers received either the inactivated vaccine or a placebo. The scientists analyzed the levels of antibodies in the participants’ blood and compared them, among other things, with those of people who were immunized with the Biontech-Pfizer vaccine in New York.
According to the further analysis of the clinical study, the number of antibodies and the neutralizing activity of Sars-CoV-2 in the blood of people vaccinated with “NDV-HXP-S” was “comparable” to that of people who received Biontech -Vaccine of Pfizer mRNA, reports the team led by first author Juan Manuel Carreño.
The antibodies produced by the new vaccine mainly attacked the region of the spike protein with which the virus binds to human cells (receptor binding domain). In contrast to the built-in immune response with mRNA vaccines, in which antibodies bind to multiple spike protein regions, the vaccine elicits a “very focused immune response.”
The advantage of the vaccine is that, like most influenza vaccines, it can be produced in chicken eggs. As this type of production is cheaper than the production of mRNA vaccines, the “NDV-HXP-S” vaccine can be produced more easily in less developed countries. The lower cost would make the vaccine attractive to low-income states, Palese and Krammer said. It is precisely there that the availability of affordable corona vaccines is low. (Husa)