A fourth coronavirus jab may be needed to improve levels of protection, a vaccine boss has said.
Chief Executive of Moderna, Stephane Bancel, explained that another vaccine this autumn would increase immunity as the efficiency of booster doses is likely to decline over the next few months.
Moderna is currently working on a vaccine tailored towards the Omicron variant that continues to spread rapidly across Scotland, the UK, and the world.
However, a fourth Covid vaccine is not yet needed, according to the Joint Committee on Vaccination and Immunisation (JCVI).
The JCVI has advised the Scottish and UK Governments throughout the Covid vaccination process. For example, the JCVI has researched and cleared booster vaccines as well as jabs for different, younger age groups.
Another booster may not be required just yet due to the high levels of protection afforded by the third dose.
Are third doses not enough?
According to the latest figures from the UK Health Security Agency, for those above 65-years-old, protection against hospitalisation remains at about 90 per cent three months after the third jab.
Protection against severe disease from only two doses of the vaccine drops to about 70 per cent after three months and may be as low as 50 per cent six months after vaccination.
This means that the JCVI recommends prioritisation of third doses, for now, opposed to fourth doses for the most vulnerable.
Professor Wei Shen Lim, the JCVI’s chair of Covid-19 immunisation explained: “The current data show the booster dose is continuing to provide high levels of protection against severe disease, even for the most vulnerable older age groups.
“For this reason, the committee has concluded there is no immediate need to introduce a second booster dose, though this will continue to be reviewed.”
How likely are fourth doses in the future?
The need for a fourth jab is being kept under 'continuous review'.
There are some countries around the world - including Israel and Chile - already offering the fourth jab to those most vulnerable as well as health and social care workers.
Data from the Octave study, carried out by the Imperial College Healthcare NHS Trust, London, has indicated that around half of the patients who had no antibody response after two doses had some kind of response after three doses.
This meant that around a quarter of immunosuppressed patients still had no responses after three doses.
Speaking to the British Medical Journal, Michelle Willicombe, leader of the Imperial College Healthcare study said:“Some immunocompromised patients aren’t making any response or inadequate responses compared with healthy controls after three doses, so they need four to even get anything detectable,”
Willicombe continued: “Giving four doses to immunocompromised patients is a very different kettle of fish from the general population where you’re just boosting the immune response.”
Vaccine boss Bancel believes that fourth doses will be offered by September this year.
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