Human Immunity and Susceptibility to Influenza A(H3)

Core Concepts

Human immunity to Influenza A(H3) viruses poses a potential pandemic risk.

Abstract

Abstract:

• Human immunity to Influenza A(H3) viruses from animals may be limited, increasing pandemic risk.
• Seroprevalence rates for swine IAVs in North America are high, indicating potential public health risk.
• Replication efficiency varies among different animal-origin IAVs, with swine H3 IAVs posing the highest risk.

Introduction:

• Influenza A(H3) viruses are endemic in humans, swine, and birds, with potential for cross-species transmission.
• Antigenic divergence between human and avian H3 IAVs increases pandemic risk.
• Swine H3 IAVs have zoonotic potential, with recorded infections in humans.
• Human immunity against swine H3 IAVs decreases over time, heightening the risk of a pandemic.

Stats

Seroprevalence rates for circulating IAVs from swine in North America were ≥51%, swine in Europe 7%–37%, and birds and equids ≤12%.

400 zoonotic infections in the United States caused by North American cluster IV-A or novel human-like H3 swine IAVs.

Four zoonotic infections with H3 IAVs from swine in Europe have been reported.

Quotes

"Public health risk may be highest for swine H3 IAVs."
"Human immunity against swine H3 IAVs decreases, increasing the pandemic risk."
"The infectious potential of swine H3 IAVs for humans is evident from >400 recorded zoonotic infections in the United States."

Key Insights Distilled From

Human Immunity and Susceptibility to Influenza A(H3)

by Elien Vandoo... at www.medscape.com 03-28-2023

http://www.medscape.com/viewarticle/988959

Deeper Inquiries

What measures can be taken to enhance human immunity against swine H3 IAVs

To enhance human immunity against swine H3 IAVs, several measures can be taken. Firstly, promoting annual influenza vaccination, which includes strains of H3 IAVs, can help boost immunity in the population. Additionally, conducting targeted vaccination campaigns for individuals at higher risk of exposure to swine H3 IAVs, such as farmers, veterinarians, and healthcare workers, can provide an added layer of protection. Education and awareness programs about the risks associated with zoonotic infections and the importance of vaccination can also help increase immunity levels. Furthermore, research into developing novel vaccine strategies, such as universal vaccines or vaccines targeting conserved regions of the virus, can contribute to enhancing immunity against swine H3 IAVs.

Is there a possibility of developing a universal vaccine against all major circulating animal H3 IAV lineages

While developing a universal vaccine against all major circulating animal H3 IAV lineages is a challenging task, it is not impossible. One approach could involve targeting conserved regions of the virus that are less prone to antigenic drift, thus providing broader protection against different H3 IAV lineages. Another strategy could be to focus on developing vaccines that induce cross-reactive immune responses against multiple H3 IAV strains. Collaborative efforts between researchers, public health agencies, and pharmaceutical companies are essential to drive research and development in this area. By leveraging advances in vaccine technology, such as mRNA vaccines or viral vector vaccines, a universal vaccine against animal H3 IAV lineages may become a reality in the future.

How can the global community collaborate to prevent potential pandemics caused by zoonotic infections

Preventing potential pandemics caused by zoonotic infections requires global collaboration and coordination. Firstly, enhancing surveillance systems to detect and monitor zoonotic infections in animals and humans is crucial for early identification and containment of potential threats. Sharing data and information across borders and between different sectors, including human and animal health, can facilitate a rapid response to emerging outbreaks. Investing in research to better understand the transmission dynamics of zoonotic infections and the factors that contribute to their spillover into human populations is also essential. International cooperation in developing and implementing strategies for preventing zoonotic infections, such as vaccination programs, biosecurity measures, and public health interventions, can help mitigate the risk of pandemics caused by animal H3 IAVs.