Will we have a serene summer in terms of health? If the French are preparing to lift the masks in transport, from Monday May 16, other regions of the globe are monitoring the development of new variants such as milk on the fire. Similar to Southern Africa, facing an increase in COVID-19 cases linked to Omicron sub-variants BA.2, BA.4 and BA.5. Several thousand kilometers away, the scenario turns out to be similar in the United States, which is currently recording an increase in the number of daily cases of Covid-19, fueled by the BA.2.12.1 subvariant.
In southern Africa, the World Health Organization (WHO) has sounded the alarm. In a press release published Thursday, May 12, the international structure evokes in this region “an increase in cases of COVID-19 for the third consecutive week, while the winter season is approaching inside this zone. This increase has put an end to a two-month drop in overall recorded infections on the continent.” During the week ending May 8, 2022, the sub-region recorded 46,271 contaminations per day, an increase of 32% compared to the previous week.
It should be noted that epidemiological data from South Africa inflate this regional assessment. In the country officially most affected by Covid-19 on the continent, the weekly cases recorded have quadrupled over the past three weeks. “South Africa has recorded 376 deaths in the past three weeks, twice as many as in the previous three weeks,” WHO said.
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South Africans are not the only ones to see their health indicators blush: Eswatini and Namibia have also recorded a resurgence of the epidemic. “These two countries have reported 50% more new cases in the past two weeks compared to the previous two weeks,” reports the WHO. Despite this increase, the number of contaminations per day remains low in Namibia, a country of 2.5 million inhabitants: as of May 10, 62 daily infections were recorded.
This new wave of the epidemic, which began at the end of April, is thought to have its origin in the appearance of the BA.4 and BA.5 variants, which follow BA.1, BA.2 and BA.3. According to one South African study, published on April 28, 2022 on the Center of Epidemic Response and Innovation (CERI) website from Stellenbosch University (Western Cape Province), the spike proteins of BA.4 and BA.5 are identical.
The United States against the BA.2.12.1 variant
But there are a few differences that distinguish them from BA.2, such as the Δ69-70 deletion and the L452R and F486V mutations. The latter “leads to a greater affinity of the virus for the cellular receptor ACE2 in mink and ferrets”, reports the South African study. In other words, the mutation at position F486 would play a role in immune escape after natural infection or vaccination.
Regarding the L452V mutation, it has been associated with an increase in the ability to bind to the ACE2 receptor, which means greater infectivity. Despite these still partial elements, further research will be necessary to draw more precise conclusions.
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On the other side of the Atlantic, Americans are also keeping their eyes glued to the health figures. As the BA.2 variant became dominant in the country earlier this spring, it is the turn of one of its descendants, the BA.2.12.1, to spread. It would represent about 42.6% of the samples sequenced during the week ending May 7, according to the United States Centers for Disease Control and Prevention (CDC). Overall, average daily diagnoses have roughly doubled nationwide since early April, the weekly reports the Time.
Although there is some optimism that the outbreak of the virus in the northeastern region of the United States has not resulted in a significant increase in hospitalizations and deaths, this part of the country has a higher level higher number of vaccinations and boosters than other regions. As infections increase in less protected areas, the health situation could deteriorate. In addition, two preliminary studies not yet peer-reviewed – one in china and one in South Africa – suggest that the new Omicron variants (BA.2.12.1, BA.4 and BA.5) would benefit from better immune escape against vaccines and previous infections.
Therefore, even people who caught the original strain of Omicron could be at risk of reinfection. But as former U.S. Food and Drug Administration Commissioner Dr. Scott Gottlieb tweeted Wednesday, May 11, those who are fully vaccinated and have recently had COVID-19 appear to have stronger protection.
On Saturday May 7, the Biden administration issued a new warning that the United States could potentially see 100 million Covid-19 infections this fall and winter, requiring additional funding from Congress to prepare the nation. As BA.2.12.1 makes its way through the United States, its spread could once again redefine the face of the epidemic that has caused more than one million deaths in the country.