Coronavirus and the flu vaccine: What you should know
In South Africa there is a debate about flu injections, yet up to 11 000 people die from the flu annually.
With Covid-19 spreading in South Africa, experts say it’s important to get flu vaccines because flu symptoms are similar to Covid-19 symptoms.
While the range of symptoms for the two viruses is similar, the fraction with severe disease appears to be different. For Covid-19, data suggests that 80% of infections are mild or asymptomatic, 15% are severe and require oxygen and 5% are critical infections, requiring ventilation. The fractions of severe and critical infection would be higher than that of flu.
Dr Morgan Mkhatshwa, the head of operations at Bonitas Medical Fund, says this is an important point of difference between flu and the coronavirus.
Flu has a shorter incubation period and can spread faster than Covid-19. Further, transmission in the first 3 to 5 days of illness, or potentially pre-symptomatic transmission, is a major driver of transmission for flu.
Although with Covid-19, people can be infected by someone 24 to 48 hours before the onset of symptoms, this is not the major driver of transmission.
According to recommendations published by the National Institute for Communicable Diseases for flu management, seasonal flu is usually transmitted during winter. It is one of the main causes of pneumonia or lower-respiratory tract infections, and between 8 and 10 percent of all patients with pneumonia test positive for flu.
In recent years, annual flu epidemics have resulted in an estimated 3 to 5 million cases of severe illness, and around 290 000 to 650 000 deaths globally.
While flu surveillance monitoring indicates that we did not experience a typical flu season last year, according to experts, this was unusual and was in most part due to the preventative measures taken against Covid-19.
The US’s Centers for Disease Control and Prevention Control dispels the myth that a flu shot cannot cause flu.
“Flu vaccines given with a needle are currently made either with flu vaccine viruses that have been ‘inactivated’ and are not infectious, or with no flu vaccine viruses at all. The most common side effects from the shot are soreness, redness, tenderness or swelling where the shot was given. Serious allergic reactions to flu vaccines are very rare,” it says.