Have you just spent five days bedridden with the flu, between fever, aches and cough? After this painful episode, you now think you will be calm, immune until next year. But is this really the case? We asked the question to Dr Gérald Kierzek, medical director of True Medical.
Real immunity… but limited
First element of the answer: catching the flu does indeed trigger an immune response. After infection, your body produces antibodies that can recognize and neutralize the virus causing your illness. But this protection has two major limits.
First, it is specific to the strain contracted. However, the flu virus (influenza) mutates quickly. Every winter, several strains circulate simultaneously, notably influenza A and B viruses. Result: being immunized against one does not mean being protected against the others.
Then, this immunity is short-lived. According to Dr. Gérald Kierzek, “it generally lasts only a few months. In a healthy adult, protection gradually diminishes and becomes significantly less effective after 6 to 12 months“.
Can you get the flu twice in the same season?
The answer is yes, although it remains relatively rare. It is entirely possible to catch the flu several times during the same winter, especially if different strains are circulating. For example, influenza A at the start of the season, then influenza B a few weeks later.
This scenario is more common in children, whose immune systems are still building, or in people who are immunocompromised. On the other hand, falling ill again due to the same strain during the same winter remains exceptional.
Also note that the flu is very contagious: an infected person can transmit the virus up to 5 to 7 days after the appearance of symptoms, which encourages repeated exposure to those around them.
Infection or vaccine: same fight?
Contrary to popular belief, the immunity acquired after the flu is not more lasting than that provided by the vaccine. Both offer comparable protection: partial, targeted and temporary.
This is why Dr Gérald Kierzek reminds us that flu vaccination remains recommended, even if you have already had the flu this season. It makes it possible to broaden protection against the strains identified as most likely to circulate.
“The vaccine can be carried out as early as 15 days after recovery” says our expert.
How to strengthen your protection after the flu?
Even if we cannot guarantee total immunity, certain actions can limit the risk of relapse or new infection:
- Flu vaccinationevery year, including after an infection;
- Hygiene measures : frequent hand washing, wearing a mask in case of symptoms, limiting close contact during the contagious period (up to 7 to 10 days);
- A lifestyle favorable to immunity : sufficient sleep, diet rich in fruits and vegetables, moderate and regular physical activity.
- In fragile people,
antiviral treatment Early treatment can reduce the duration and severity of the disease.
Having had the flu therefore does not mean being protected for the entire season, even less for the following year. Caution therefore: even after having gone through the ordeal, good reflexes remain essential.