The European Medicines Agency (EMA) has ventured this week that repeated booster doses of vaccine risked overloading people's immune systems and was not a sustainable strategy.
However, the body admitted more evidence was needed to corroborate the theory. EMA also suggested the omicron variant could offer natural Covid immunity without need for additional injections and suggested countries should start thinking about administering booster doses at longer intervals.
Nobody knows exactly when we will be at the end of the tunnel but we will be there, Marco Cavaleri, head of vaccine strategy at the Amsterdam-based regulator, told journalists.
With the increase of immunity in population – and with omicron, there will be a lot of natural immunity taking place on top of vaccination – we will be fast moving towards a scenario that will be closer to endemicity.”
Cavaleri also spoke of omicron’s huge burden on healthcare systems, saying the world should not forget “we are still in a pandemic.” Countries, he added, should start thinking about spacing out the time between boosters at longer intervals, and synchronising them with the start of the cold season like flu vaccines.
The expert also said the risk of hospitalization from omicron was between a third and half of that posed by Delta, despite the fact omicron was more contagious.
With the new South African strain, COVID-19 seems to be shifting from a pandemic scenario to an endemic one, which means a population has gained enough widespread immunity that transmissions, hospitalizations and deaths will start to go down.
Reports from South Africa, where omicron was first detected, have indicated that while the variant is highly infectious, it does not result in a corresponding spike in hospitalizations and deaths. Another South African study released last month found that omicron may reduce infections caused by the Delta variant by building cross-immunity to different strains, an effect that has not been observed in many other mutations of the SARS-CoV-2 virus.
While use of additional boosters can be part of contingency plans, repeated vaccinations within short intervals would not represent a sustainable long-term strategy, Cavaleri said.
It is important that there is a good discussion around the choice of the composition of the vaccine to make sure that we have a strategy that is not just reactive ... and try to come up with an approach that will be suitable in order to prevent a future variant, he added.
Cavaleri's remarks echo those of British infectious disease expert Sir Andrew Pollard, who said earlier this month that repeated vaccination every few months was not sustainable. Pollard, who helped to develop the AstraZeneca COVID-19 vaccine, said, It really is not affordable, sustainable or probably even needed to vaccinate everyone on the planet every four to six months.
We haven't even managed to vaccinate everyone in Africa with one dose so we're certainly not going to get to a point where fourth doses for everyone is manageable,” he added.
Earlier this week, the World Health Organization (WHO) said more than half of people in Europe were on track to catch the variant within the next two months.