Influenza Virus

The influenza A virus – cause of great influenza pandemics

Smallpox vaccines

Influenza, commonly known as flu, is an infectious disease caused primarily by the influenza virus type A; it is the most highly pathogenic influenza virus genus for humans. Besides type A there are type B, C, and D, all RNA viruses, and all genera of the family Orthomyxoviridae. Types B and C are much less pathogenic for humans; a type D infection of humans so far has never been verified.

The influenza A virus is subdivided into subtypes or serotypes based upon its surface antigens, in particular hemagglutinin (H) and neuraminidase (N). There are also variations in the H and N antigens; however, they are all shaped like spikes and presented on the viral envelope. The individual influenza A virus serotype is named according to these glycoprotein antigens – for example, H1N1, which caused the Spanish flu in 1918, or H3N2, which caused Hong Kong Flu in 1968.

Furthermore, influenza A virus serotypes can easily generate various strains, which may differ in their pathogenicity. Thus, during the 1918 pandemic of a particular H1N1 strain, around 500 million people became infected with this virus and millions of people word wide died. The high mortality in healthy people was a unique feature of this pandemic. For another pandemic of a different H1N1 strain in 2009 the death rate was about the longtime annual average and hence much lower compared to the H1N1 pandemic in 1918.

Vaccination – today’s perfect protection from flu

Influenza or flu starts with high fever and a generalized feeling of illness. The severity of the disease course depends on the body’s own defense-strength and – what matters much – on the virus serotype and strain.

CRS Kiel
In addition to antiviral therapy (Oseltamivir, Zanamivir) for acute cases, a vaccination is generally recommended to prevent an influenza virus infection, especially for people over 60, pregnant women and individuals working in a medical profession.
CRS Group Karriere

CRS Berlin and its Outstanding Expertise

Because the influenza virus tends to mutate, new virus serotypes and virus strains are detected again and again. Thus, ongoing research for new vaccines against the influenza virus remains crucial.

We at CRS have more than 40 years of experience in conducting well-designed clinical trials with vaccines to generate most convincing evidence. Furthermore we have own clinics for trial participants in four major German cities. We are thus a best place to conduct your next influenza vaccine clinical trial.