The tapering off of the Omicron wave of Covid-19 does not mean the two-year novel coronavirus pandemic is nearing the end, an expert on global health and outbreaks has said.
Dr Máire Connolly, Professor of Global Health and Development at the School of Medicine in NUI Galway, said there were grounds of optimism in relation to Omicron but added that low vaccination levels in the least developed countries posed a significant risk.
She said vaccination deficits would allow viruses to circulate for longer. In that scenario, there was a greater chance of new mutations occurring, with no guarantee that it would not be more virulent than Omicron.
“The bottom line is we do not know what is out there,” she said. “There is a natural progression with viruses to become less pathogenic, less severe over time. We saw it with Ebola.
“But it’s not necessarily the case. These are random mutations that can happen just as easily to make something more transmissible but also more severe.”
Prof Connolly, who worked for 15 years for the World Health Organisation (WHO), said the low level of vaccination worldwide is creating the potential for “variant factories”.
The director general of the WHO Dr Tedros Adhanom Ghebreyesus set a target of global vaccine coverage of 70 per cent by July this year.
It is nowhere near that rate.
“The vaccines we have work at the moment but there is no guarantee that the next variant will not have greater levels of vaccine escape . . . We have a window of time in the next three or four months,” she warned.
“The rate of variant generation will depend on vaccine uptake rates around the world.
“There is a risk that somebody who is immune-compromised will carry the virus for a longer length of time creating the conditions for mutations to happen.
“What vaccination does is it not only reduces the severity but also reduces the length of time the virus remains in your body so it clears quickly.”
She said another other risk was that the more coronavirus circulated the more likely it was to “bounce” into another species such as mink or domestic animals.
“That’s when you get really tricky mutations happening, the weird novel coronaviruses.” She instanced Sars 1 which affected civet cats, and Mers which affected dromedaries.
“New variants are generated. It does not necessarily mean they will be milder because these are random mutations.”
Dr Connolly said the combination of high vaccination rates and widespread infection have created high immunity levels among Irish people. As spring progresses, more people will go outdoors, thus suppressing rates further.
For her, the waning effect of Omicron upon vaccines was really significant as was the speed at which it came to dominate infections. “How it took over is incredible. It had not been detected until the end of November and now it is at about 95 per cent in Ireland,” she said.
“The majority of cases in ICU are Delta although they are accounting for about 4 to 5 per cent [overall] and that is reducing all the time.”
She said the Covax programme to increase vaccination rates in less developed countries was not achieving the desired scale and that the pharmaceutical industry needed to play its part.
“India and China have the capacity to make vaccines at scale . . . Pharmaceutical companies should hand over their patents and allow companies in those countries to make these vaccines,” she said.
Prof Connolly is the co-ordinator in NUIG for Pandem, a European Union Programme which is designing new systems to help first responders and teams deal with pandemic risk and emergency management.