The National Institute of Communicable Diseases (NICD) has said that it is highly likely that Covid-19 vaccinations will need to be administered yearly in the form of a booster shot.
This is the result of the evolution of more Covid-19 strains that diminish antibody reactions to vaccines, combined with the fact that the antibodies deteriorate over time.
Speaking to SABC News, Catherine Scheepers, a senior medical scientist at the NICD’s centre for HIV/Aids and STIs virology group, explained that mutations in viruses are common, and as more people are infected, the chance of mutation increases.
According to Scheepers, most vaccines on the market were developed from the original strain, and new variants have evolved to be more efficient in terms of infection and evading the immune system.
Like the flu shot, these vaccines will need to be modified to match variants in circulation at the time, meaning at some point, we will need these modified vaccines administered in the form of booster shots.
“At this point, it probably would be likely that we would need to get a booster shot,” she said.
Scheepers also provided insight into the natural versus engineered immunity debate — suggesting that antibodies provided by the vaccine offer better protection.
These engineered antibodies have been adapted to have a longer half-life, meaning that they will persist in your body for longer than naturally developed antibodies and offer better blocking of the virus.
According to Noluthando Nematswerani, head of the centre for clinical excellence at Discovery Health, “booster shots are needed to gain the maximum possible immune response” with viral diseases, such as influenza and Covid-19.
This is because these viruses mutate, “making the previous year’s vaccine less effective, and requiring an updated flu vaccine every year,” she said.
New research from Kings College London indicates coronavirus vaccines also help to prevent “Long Covid” — where symptoms persist for months — in addition to reducing the chance of infection and severe illness.
The study indicated that being fully vaccinated reduces the chance of developing long covid by 50%.