When a person is exposed to an influenza virus, the innate and subsequently the adaptive or specific immune response kicks in and provides defence against the invading virus. Depending on the nature of the virus and the effectiveness of the immune response, the infected individual suffers from more or less severe consequences of the influenza […]
In the past, new strains have generated pandemics causing high death rates and major disruptions to society. Although healthcare has improved in recent decades, epidemiological models project that today a pandemic is likely to result in 2 to 7.4 million deaths globally. In developed countries alone, accounting for 15% of the world’s population, models project […]
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 […]
in the Northern Hemisphere, the best time to be vaccinated is from mid-October to mid-November. This will ensure protection before the beginning and throughout the duration of the annual epidemic circulation of influenza viruses, which usually occurs from November to April. In the Southern Hemisphere, the best time to be vaccinated is from mid-March to […]
Clinical diagnosis The clinical symptoms of influenza are fairly characteristic, and during periods of epidemics enable a sufficiently reliable diagnosis to be made. For general practitioners, they form the basis for diagnosing influenza. During differential diagnosis, account must be taken of conditions such as: the common cold, infections caused by other types of viruses and […]
Influenza A viruses continuously undergo antigenic evolution. Since the viral surface glycoprotein HA is the antigen against which virus-neutralizing antibodies are directed, it is primarily the antigenic variation of HA that is responsible for the immune escape of influenza viruses. Two distinct mechanisms of antigenic evolution can be identified: antigenic drift causes regular influenza epidemics, […]
Morphology and structure The influenza virus belongs to the RNA viruses and comes from the family of Orthomyxoviridae. It is usually spherical in shape with a diameter of 80-120 nm. There are 3 distinct types of influenza virus: A, B and C. The genome consists of 8 (type A and B viruses) or 7 (type […]
