As the temperature drops, it is common that some people develop conditions such as runny nose and a couple of coughs. We would pay little attention to them if there were not the fourth outbreak of COVID-19; but now, even mild flu symptoms can already make people panic whether they had actually contracted the COVID-19.

To make things worse, recent studies show that an influenza infection will leave one more vulnerable in catching COVID-19, and if unfortunately infected by both, the potential bodily harm is thought to be more profound. So how do we extend extra protection for oneself and family?

Doubly hit, doubly transmittable

What would happen if someone is doubly hit by influenza and COVID-19? A recent study by HKU’s microbiology department revealed that for hamsters that were infected by both influenza and COVID-19, lung damages were significantly more severe when compared with those infected by a either disease. The study also revealed that, the antibody response for COVID-19 was worse in those hamsters that had both infections, implying that the impact was more severe.

These results in an animal study do not necessarily extrapolate into human. That said, from what we understand, both influenza and COVID-19 can cause damage to the lungs, so a compound effect with co-infection is not impossible.

Furthermore, another research on human subjects indicated that the ability for people to transmit COVID-19 is doubled if they were infected by both influenza and COVID-19.

Take jabs ASAP and brace for winter surge

Based on these two studies, the medical profession in general agrees that we should avoid co-infection. Since a COVID-19 vaccine is not available at this point, preventing influenza is therefore even more important.

Demand for flu jabs is high this year and many clinics went out of stock. With replenishing shipment arriving, the supply is stabilising. It is crucial for us to grasp the last chance of inoculation before the winter surge arrives, for it takes around two weeks after vaccination for our body to develop the full immune response.

It must be emphasised that vaccine protection is not 100%. We must therefore continue to vigilantly observe universal masking, hand hygiene and maintain social distancing to minimise the risk of catching either virus.