Influenza is an acute and highly contagious respiratory infection that can lead to serious complications and death. The disease can affect people of all ages and is easily transmitted through coughing, sneezing and close contact with a contaminated person or surface. Symptoms of the flu include fever / chills, cough, sore throat, nasal congestion, muscle aches, headache and tiredness.
According to the World Health Organization (WHO), hospitalizations and deaths occur mainly in at-risk groups – children under 5 years of age, pregnant women, the chronically ill and the elderly. Globally, annual epidemics are estimated to lead to approximately 3 to 5 million serious illnesses and approximately 290,000 to 650,000 deaths.
The importance of influenza vaccination annually
Vaccination is the best way to prevent, reduce serious complications and reduce the number of deaths associated with this disease. WHO makes annual recommendations on the composition of influenza vaccines in both the northern and southern hemispheres. Dr. Emersom Mesquita, GSK’s infectious disease specialist and medical director of vaccines, explains the importance and reason for these recommendations. “Like other viruses, the influenza virus goes through small changes during the reproductive process. In practice, these modifications are a way to escape the immune response elicited by vaccination. For this reason, the WHO makes annual recommendations on the composition of influenza vaccines, ”he says.
For 2022, the vaccine was formulated from influenza virus strains reported by the WHO for that year and approved by Anvisa. The purpose of these recommendations is to update the composition of the vaccines to keep up with the changes in the virus. “It is therefore clear why influenza vaccination should be taken every year. In addition, it is worth noting that annual vaccination allows the level of antibodies in the protective molecules of the immune system to reach ideal levels, ”explains Emersom.
Those vaccinated by the end of 2021 should be re-vaccinated in 2022, warns the infectologist
The increase in cases of the H3N2 variant at the end of 2021 led to a demand for an influenza vaccine. However, the composition of the 2021 vaccine is different from that currently available in 2022, and therefore even those vaccinated at the end of 2021 will benefit from receiving the new 2022 vaccine. Keep in mind that the flu is seasonal, meaning most cases focus on a specific time of year, winter. Therefore, we ideally recommend vaccination before the start of this period, when the body will have a strong antibody response against the disease, “explains the infectologist.
Public network and private network
A trivalent vaccine, a vaccine that provides protection against two influenza As (H1N1 and H3N2) and one influenza B (Victoria or Yamagata), is provided free of charge by the Unified Health System (SUS). publications throughout Brazil, targeting people aged 60 and over; children from 6 months to less than 5 years of age; pregnant women; women up to 45 days after delivery (women born); health professionals; primary and university teachers; Indian people; people with chronic non-communicable diseases and other specific diseases; permanently disabled; truck drivers; urban and long-distance public transport workers; port workers; security and rescue forces; army; young people and young people aged 12 to 21 in the context of socio-educational activities; freedom of the deprived population; and prison staff.
In the private network, it is also possible to vaccinate with a tetravalent vaccine that provides protection against two influenza A (H1N1 and H3N2) and two influenza B (Victoria and Yamagata), available from 6 months of age. .
In addition to vaccination, other forms of flu prevention include maintaining hygiene practices, such as washing your hands well and often with soap and water, and covering your mouth and nose with a disposable towel when coughing or sneezing.
The myth of influenza vaccination
One of the biggest myths about flu vaccinations is that the vaccine causes the flu. However, explains Dr. Emersom, this is not possible. – The vaccine is prevented from causing the disease by the fact that it is made up of inactivated viruses, that is, viruses whose ability to reproduce has been eliminated. In practice, some vaccine-related reactions, such as headaches and muscle pain, can be mistaken for the flu, ”he points out.
The difference between the flu and the common cold
In the case of a cold, the symptoms are milder and last for a shorter time, although they are similar and are commonly confused with the symptoms of the flu. In this case, it is also a respiratory disease, but it is caused by various viruses, such as rhinoviruses, parainfluenza viruses, and the respiratory syncytial virus, which usually affect children.