WAVE

Covid-19 wave appears to follow cold weather, says global agency

The ongoing rains in Kenya are expected until the beginning of January.

In Summary
  • In Kenya, positivity rate has surged from 1 per cent on December 1 to the current 29 per cent, mirroring the ongoing rains.
  • However, it said weather was just one player and there were other factors influencing transmission, such as new variants, vaccination rates and government policy.
City dwellers and most travelers traveling upcountry for the festive season are caught by the rain as they find their way to Machakos Bus Station Nairobi on Tuesday 21, December./WILFRED NYANGARESI
City dwellers and most travelers traveling upcountry for the festive season are caught by the rain as they find their way to Machakos Bus Station Nairobi on Tuesday 21, December./WILFRED NYANGARESI

The increased Covid-19 transmission could be linked to current temperate weather, according to the World Meteorological Organization (WMO).

The global weather agency said there is now enough evidence that weather influences Sars-Cov-2 transmission.

In Kenya, positivity rate has surged from one per cent on December 1 to the current 29 per cent, mirroring the ongoing rains.

“Many, but not all, temperate zone countries experienced significant Covid-19 peaks in the winter of 2020-2021, and in the late fall of 2021 there has been a troubling rise in cases in many of the same regions,” WMO said in a statement.

However, it said weather was just one player and there were other factors influencing transmission, such as new variants, vaccination rates and government policy.

As of Wednesday, only 9.2 million Kenyans had been vaccinated against Covid-19.

In March 2021, a WMO team noted that in the first year of the Covid-19 pandemic, transmission risk responded more strongly to policy and behavioral change than it did to seasonal weather conditions.

Since then, research on Covid-19 seasonality has advanced.

A longer, more reliable Covid-19 data record has yielded a number of epidemiological studies that robustly demonstrate seasonally-mediated risk patterns, WMO said in its latest statement. 

“These studies point to higher risk of transmission in winter in temperate zones, and, indeed, many mid-latitude countries have experienced waves of infections in fall and winter,” it said.

However, major Covid-19 transmission peaks were observed in many countries in the warm seasons of 2021, and dangerous variants have emerged independent of seasonality—for example, the highly contagious Omicron variant.

Thus, while scientific evidence of seasonal effects on transmission has become stronger, significant and sometimes dominant risk factors can emerge at any time of the year.

“It makes sense to prepare for increases in Covid-19 case numbers and severity in cold seasons in colder climate zones, and meteorological services can work with health services to communicate this message and to plan for distribution of adequate health resources and information,” said Dr Ben Zaitchik of Johns Hopkins University and co-chair of the WMO Covid-19 Task Team.

The ongoing rains in Kenya are expected until the beginning of January.

On Wednesday, the Health ministry maintained that the directive requiring proof of vaccination against Covid-19 will be fully implemented.

The directive, which was to come into effect on December 21, requires that all those seeking in-person government services must provide evidence that they have been vaccinated.

“I want to tell those who are going to the village to make sure that you are vaccinated. You may get stuck.  You may not be able to board a matatu back because these measures will be implemented,” vaccines deployment taskforce chairman Willis Akhwale said.