What can healthcare workers do?

Get vaccinated! Influenza vaccination is the best way to reduce chances of getting ill from influenza and from giving influenza to patients, co-workers and family. Indications are that vaccination against seasonal influenza at least partially protects against possible pandemic influenza strains. Also consider this: if one third of the population receives its annual shot with […]

Pandemic alert phases

The World Health Organization (WHO) has developed an alert system to help inform the world about the development of the different stages towards a pandemic. The alert system is comprised of six phases. The current situation with the HPAI-H5N1 virus in animals and humans places the world in pandemic alert phase 3. This means that […]

Pandemic preparedness planning

Detailed planning is essential to ensure a coordinated response to an influenza pandemic, both at the national and international levels. Should schools be closed to prevent influenza from spreading? What about hospital capacity in case of a severe pandemic? How can we track the pandemic virus as it spreads? How and to whom will the […]

Vaccination during a pandemic

Since it is impossible to vaccinate the entire world population against a pandemic influenza virus when a pandemic emerges, it is necessary to determine which groups must be immunized with priority. After all, effective allocation of vaccines will play a critical role in slowing down the spread of the influenza pandemic and reducing its effects […]

Pandemics in the 20th century

When a new influenza virus appears, against which the human population has no immunity, a pandemic may occur. This happened in 1918 (the “Spanish flu”, caused by an H1N1 subtype), in 1957 (the “Asian flu” caused by an H2N2 subtype) and in 1968 (the “Hong Kong flu”, caused by an H3N2 subtype). Of all pandemics, […]

How do pandemics Occur

An influenza pandemic is a global outbreak of influenza and occurs when a new influenza virus emerges, spreads and causes disease worldwide. Influenza A viruses continuously undergo antigenic evolution. There are two main mechanisms by which they do so: antigenic drift causes regular influenza epidemics, while antigenic shift is the cause of occasional global outbreaks […]


Adjuvants are substances that can be added to human vaccines. They stimulate the immune system and increase the response to a vaccine, without having a specific antigenic effect themselves. The advantages, certainly in a pandemic situation, are obvious: they improve the immune response whilst the dose size (the amount of virus material or antigen in […]

A pandemic influenza vaccine

To prepare the world for the next influenza pandemic, the WHO has advised national governments to develop pandemic preparedness plans. The production, distribution and administration of a pandemic influenza vaccine play a major role in such plans. Pandemic influenza vaccines would reduce spreading of the virus and the burden of disease in the population, like […]

Vaccines in cultured cells

An alternative way of producing influenza virus for vaccine production is based on the use of cell cultures in a biological fermentation process. Mammalian cells are usually used for this purpose. The cells are infected with the virus and the virus is left to multiply for several days. During the course of this process, most […]

A lethal virus

The deadliness of an influenza virus mainly depends on its ability to efficiently suppress the innate immune system, thereby allowing high levels of virus replication. This is more likely to occur with pandemic influenza where the individual has not been exposed to the new virus subtype before and must rely on the innate immune response […]