Rising Bird Flu Cases in Cattle and Humans Drive Global Efforts in Vaccination, Genetic Monitoring, and Surveillance

Avian influenza, referred to as bird flu, is emerging as a significant health threat with rising cases in both cattle and humans. Understanding its current state, the factors contributing to its transmissibility, and the strategies implemented by nations worldwide are critical for global preparedness and mitigating the risk of a potential pandemic.

Avian Influenza’s Methods of Action and Transmissibility May Lead to Potential Pandemic

Avian influenza is a contagious viral infection that primarily affects bird specimens. The virus belongs to the influenza type A group and is classified based on two of its surface proteins: hemagglutinin (H) and neuraminidase (N). These proteins are crucial for determining the virus’s ability to bind to host cells and facilitate entry. Avian influenza can lead to a series of symptoms depending on its two main strains, low pathogenic avian influenza (LPAI), which causes mild or asymptomatic infections, and highly pathogenic avian influenza (HPAI), which may cause severe disease and increase mortality. 

Recently, H5N1 and H7N9 strains have raised global concerns due to their ability to infect humans. So far, researchers have categorized human infections as rare, with only a minority of cases confirmed. Its transmission has shown to occur primarily through direct contact with infected specimens or contaminated environments, including bird markets or cattle farms. If untreated, these infections may lead to severe respiratory illnesses, and in some cases, death. Human-to-human transmission of the virus is currently limited, however the potential for it to mutate into a form that is able to spread easily among humans portrays a significant pandemic threat. 

To mitigate the risk of the virus becoming a widespread human health crisis, authorities must implement effective public health strategies. Immunologist at the University of Pennsylvania in Philadelphia, Scott Hensley stated, “This virus in its current state does not look like it has the characteristics of causing a pandemic. But with influenza viruses, that equation could entirely change with a single mutation”.

WHO Initiatives and International Efforts for Avian Influenza Prevention Through Vaccine Evaluation

Countries worldwide are searching for effective preparedness strategies for the possible avian influenza pandemic. Several of them have proposed plans of action to combat the virus, including enhancing surveillance by rigorously monitoring wild bird populations and domestic cattle farms to detect early signs of outbreaks. Additionally, rapid identification reporting of suspected cases are crucial for implementing effective containment measures. 

Researchers are concentrating on developing effective vaccines against the influenza strains, as well as creating antiviral treatments to alleviate symptoms and reduce the severity of infections. Vaccinating additionally reduces the risk of H5N1 combining with seasonal influenza viruses that are already highly adapted for human transmission. The World Health Organization (WHO) in Switzerland began evaluating existing influenza candidate vaccines and affirmed their effectiveness against the circulating H5N1 virus in cattle. Head of epidemic and pandemic preparedness and prevention at WHO, Maria Van Kerkhove expressed, “Although the current public health risk is low, WHO is operating in a constant state of readiness for a potential influenza pandemic”

Current available vaccines consist of inactivated strains of viruses grown in chicken eggs, which are less effective due to their slower production process and potential mismatch with circulating viral strains. Therefore, researchers are aiming to develop vaccines that utilize mRNA technology and have their formulation target emerging strains. The U.S Department of Health and Human Services announced earlier this month that it will provide Moderna, Inc. with US$176 million for the development of an mRNA-based vaccine against H5 influenza. By leveraging mRNA technology, researchers hope to create a more effective and adaptable vaccine to address new variants. Immunologist, Scott Hensley, reemphasized, “It really is a game-changer. In the case of a pandemic, you can expect that these vaccines will be used widely.”

Discovery of Bird Flu in Cattle Leads to New Diagnostic Procedures and Genetic Surveillance

Before the U.S. outbreak, researchers believed cattle couldn’t be infected with the virus. As results showed otherwise, they are currently trying to develop host-specific tests for precise identification. Additionally, scientists are also monitoring modifications to the virus’s genome sequence that would enhance its capacity to infect cells found in the upper respiratory tract. A group of researchers has created a library containing every possible amino-acid mutation on the haemagglutinin protein that the virus utilizes to enter cells. They examined in human cells the stability of the mutant proteins under acidic conditions as well as their ability to attach to upper-airway receptors. Co-author of the study, Thomas P. Peacock stated that scanning for these mutations could in fact allow real-time risk predictions.

Limited resources in certain regions pose barriers to implementing comprehensive surveillance, vaccination programs, and public health interventions. The potential for bird flu to spark a human pandemic shows the necessity of proactive global preparedness efforts. Promoting international cooperation will improve preparedness to lessen the effects of a potential danger to world health in the future.

Author

Denisse Sandoval