Europe approves vaccine that should stop next pandemic Society

After the traumatic devastation caused by the coronavirus, scientists and governments around the world are relentlessly monitoring any threats that could spark a new pandemic. All eyes turn to a common suspect: the influenza virus. Another reason for this is that the worst bird flu epidemic in history continues, killing hundreds of millions of people since 2021…

Subscribe to continue reading

Reading without limits

After the traumatic devastation caused by the coronavirus, scientists and governments around the world are relentlessly monitoring any threats that could spark a new pandemic. All eyes turn to a common suspect: the influenza virus. Another reason for this is that the worst bird flu outbreak to date is still ongoing, killing hundreds of millions of birds since 2021 and causing some worrying infections in mammalian species. Many experts worry that the pathogen could mutate and adapt to humans. “This bird flu is a sword of Damocles that will always hang over our heads. We should not ignore it because it could become the next pandemic,” said Daniel Lopez, former director of crisis health operations at the World Health Organization. Acuña said.

The European Medicines Agency (EMA) announced on February 22 the approval of a pre-pandemic vaccine that would become a key tool in combating an avian influenza crisis and saving millions of lives if it does occur. In fact, the agency validated both formulations, although both could be considered slightly different versions of the same drug. The first one, already complete and ready for production, is based on a known virus already circulating in birds. The second, on the other hand, is the future, a vaccine that will be produced according to the same procedure, but adapted to the form of the virus that causes a pandemic tomorrow.

“This is a huge improvement,” said Raúl Ortiz de Lejarazu, honorary director of the National Influenza Center in Valladolid. “These vaccines, already approved, will allow us to respond almost immediately to a possible pandemic, which would be earlier than with the coronavirus. Additionally, because their production system grows the virus in cells rather than in eggs , so it is a new type of vaccine, which gives it huge technical and logistical advantages,” the expert said.

The first of two vaccines approved by the EMA is called Celldemic. “It’s based on an avian influenza strain that circulated in turkeys in 2005 and was able to mount a very effective immune response against viruses that are currently circulating,” said Inma Ku, director of the National Influenza Center’s Respiratory Viruses and Influenza Laboratory. Inmaculada Casas explains. Microbiology (CNM).

The vaccine uses two proteins on the surface of the virus called hemagglutinin and neuraminidase, which form different types of pathogens in various combinations (18 in the first and 11 in the second), and give them their respective roles. Name (H5N1 among current avian influenza viruses). It is these proteins, called subunits, that trigger the immune system response.

There are already veterinary vaccines for poultry to protect against the current avian flu, but this is the first approved to protect humans. According to the EMA, “It is intended to immunize during outbreaks of zoonotic influenza, including when public health authorities anticipate a potential pandemic.” “The aim is to protect risk groups such as poultry farm workers and their contacts (family members) , friends…),” Casas added. Currently, these groups are vaccinated against seasonal influenza when deemed necessary, which, although in smaller numbers, provides some protection.

Inclipan is the name of the second approved vaccine and is “used only when an influenza pandemic is officially declared,” according to information provided by the EMA. “In reality, it is the manufacturing system or platform that is approved in this case, because the viral subunits (hemagglutinin and neuraminidase) that may be responsible for future pandemics are not yet known,” explains Ortiz de Lejarazu.

A spokesman for the Spanish Agency for Medicines and Healthcare Products (AEMPS) noted that such approval is possible because “although the strain may change, it will be in the same form of the virus and, therefore, very similar.” This allows regulatory agencies to pre-validate efficacy and safety and approve dosing, dosing guidelines…

Both vaccines will be given in two doses, three weeks apart, for adults and children aged six months and older. The most common side effects in adults are local pain at the injection site, fatigue, headache… Young children aged six months to six years may also experience fever, irritability, and temporary changes in sleep and appetite patterns.

The pharmaceutical company developing both vaccines is CSL Seqirus, one of the world’s largest vaccine manufacturers. The company has not yet responded to questions from The Nation.

All experts consulted stressed that the production system for the new vaccine requires growing the virus in cells rather than in the vaccine, a significant change. Fernando Moraga-Llop, spokesman for the Spanish Vaccinology Association (AEV), concluded: “You forget about the hundreds or billions of eggs required to produce a vaccine.”

The first step in producing a flu vaccine is to allow the virus it targets to replicate. Traditionally, this is done by inoculating them into fertilized eggs. Subsequently, the obtained virus is processed to extract the subunits (hemagglutinin and neuraminidase) used for dosing. “But it requires very complex logistics at all levels to always deliver fertilized eggs in the quantity and quality conditions you need. And it also carries a significant risk: in the event of an avian influenza pandemic, layer farms are likely to When there is an epidemic, at the worst possible time it can cause shortages,” explains Ortiz de Lejarazu.

Moraga-Loppe added that there are two other problems with egg culture: “By inoculating it into eggs, you cause it to replicate in another species as a host, which could lead to adaptive mutations that reduce How the vaccine works in humans.” And, for some patients, it can also cause problems due to egg allergy. “

Cell culture, on the other hand, avoids all these limitations. “It’s made from mammalian cells. It can be kept in a laboratory at minus 80 degrees and takes up very little space. When you need them, you can have millions ready in a very short time flasks to produce the vaccine. All of this gives you tremendous flexibility, scalability and speed. If you produce about 1.5 billion doses of influenza vaccine per year now, with cell culture we can easily get to 6 billion.” Ortiz de Lejarazu said.

Now that most of the technical issues involved in vaccine development and production have been resolved, some questions remain: How governments and international organizations should use this tool to provide greater security for the world’s people. López Acuña said there is still much work to be done in this area: “A global production plan must be agreed upon that provides for and ensures the production and distribution of the required doses for the entire planet. The establishment of a global production plan should also be considered Strategic stocks of vaccines for use at the beginning of the crisis. These are two key issues that countries and the European Commission should address within the World Health Organization (WHO),” the expert concluded.

Source link

Leave a Comment