What is the flu and what are the main symptoms?
The flu is a common virus, typically in the population during the colder months. The flu is caused by the Influenza virus. It results in mainly upper respiratory symptoms, affecting the nose and throat, often causing a cough, sore throat, and a runny or blocked nose. It can sometimes cause lower respiratory symptoms which affects the lungs, causing shortness of breath and difficulty breathing. In addition to the above, it will also cause the symptoms which are common to nearly all viruses; fever, body aches and pains, tiredness and headaches.

 Does the flu share symptoms with Covid?
It can be very difficult to distinguish between Flu and Covid based on symptoms alone. 

As they are both viruses, they both cause the common viral symptoms mentioned above in addition to symptoms that affect the upper and lower respiratory tracts. Although the viruses that cause both illnesses are highly contagious, Covid appears to spread more easily and can cause more serious illnesses. It has also been found that Covid appears to take longer before people show symptoms and they can be contagious for longer.

What was the impact of the flu last year?
In the 2020/21 season, there were extremely low levels of influenza across the UK, with an absence of the usual winter spike in rates. Compared to an average over the past 5 years, the most recent levels were at a record low throughout the flu season. This is due to the impact of national lockdowns, social distancing guidance, public health messaging regarding hand hygiene and infection control, and wearing of face coverings along with very little international travel. 

These measures were implemented due to the COVID-19 pandemic but there was also a change in health behaviours that helped reduce the risk of getting the flu. One of the most effective changes in health behaviours to prevent flu was a record high uptake of flu vaccinations. However, due to this record low level of the flu, there is concern around the potential impact this may have on the 2021/22 flu season.  

What does this mean for the 2021/22 flu season?
Due to the very low flu infection rates over the past year, there has been very low virus-induced immunity from influenza strains. This means that we have not had a ‘top up’ of antibodies from natural infection and as a result, we may see more people become infected. In addition to this, we may also see more serious illness and hospitalisation rather than the usual mild illness that most of us have experienced in the past. This same concept applies to most of the other winter respiratory viruses but illness from flu can be reduced by early vaccination.

How does the flu vaccine work?
Flu vaccines work similarly to most other vaccines which is by causing the immune system to mount a response to it and subsequently produce antibodies. These antibodies will help to provide protection against the influenza viruses and therefore help reduce the risk of getting the infection or reduce the severity of the illness when infected. Once vaccinated it takes around two weeks for you to benefit from the vaccination. This is all very similar to that of the Covid vaccine. 

The flu vaccine is given annually as the influenza viruses constantly adapt by making small genetic changes and as a result, the new vaccines have to ensure protection is delivered for the most up to date strain. Vaccinations from previous years are unlikely to provide any protection against the new strains.  

Who should take the flu vaccine? Is it just older and vulnerable people who should take it, or this year should we all look to take the jab?
Nearly everyone can benefit from having the flu vaccine. With the added risks from diminished immunity to flu from the lack of recent infection, it would be even more beneficial to be vaccinated.  This will provide a higher chance of keeping well in the presence of COVID-19 and other respiratory illnesses especially in the event of co-existing infections.  

There are however specific groups of people that are routinely encouraged to have a vaccine and are invited by their GP. This includes:

• Children aged 2 to 11
• Those aged 65 or over
• Pregnant women
• Those living in long-stay residential care homes
• Carers
• Health and social care workers
• Those aged 6 months to 65 years in at-risk groups which includes people with the below chronic illnesses:
• Respiratory diseases
• Heart disease, kidney disease or liver disease
• Neurological disease including learning disability
• Diabetes
• Diseases causing immunosuppression
• Splenectomy, sickle cell anaemia or coeliac disease

When should we take it to have maximum impact?
The flu vaccine should be taken before outbreaks of flu start. The peak of flu in the UK is usually in November and therefore vaccinations can be taken from September onwards.