After weeks of decline, the global number of COVID-19 cases is now ticking again. This resurgence raises concerns that we could see another wave amid relaxed health measures and the emergence of the omicron subvariant BA.2, the most transmissible version of the virus identified to date.
According to the World Health Organization’s latest COVID-19 Situation Report, the global number of new weekly cases rose 8 percent for the week ending March 13, totaling more than 11 million cases. The number of cases is increasing in the Western Pacific, European and African regions. Korea, Vietnam, Germany, France and the Netherlands reported the highest number of new cases.
“These increases are occurring despite reductions in testing in some countries, meaning the cases we are seeing are just the tip of the iceberg,” said World Health Organization director general Dr. Tedros Adhanom Ghebreyesus, in a press conference on Wednesday. †
Some countries, such as China, are now struggling with their first wave of omicron cases, while others, such as those in Europe, are seeing a resurgence in cases amid the rise of BA.2. The subvariant is thought to be about 30 to 40 percent more transmissible than the original omicron variant that spread worldwide, BA.1.
“Each country faces a different situation with different challenges, but the pandemic is not over yet,” said Dr. Tedros.
The good news about BA.2 is that vaccines and most treatments work just as well against the new subvariant as they do against BA.1. And studies have suggested that previous infection with BA.1 may protect against infection with BA.2. In addition, BA.2 does not appear to cause more severe disease than seen with BA.1.
But BA.2 is more portable and quickly overtakes BA.1 as the globally dominant variant. In Wednesday’s press conference, Maria Van Kerkhove, WHO technical leader on COVID-19, noted that in the past 30 days, 99.9 percent of all SARS-CoV-2 viruses sequenced worldwide were ommicrons. Of those sequenced ommicron viruses, approximately 75 percent were BA.2 and the remaining 25 percent were BA.1.
“not over”
She added a warning, saying that the data now being collected is faltering. “We’re seeing an increase in the proportion of BA.2 being detected, but the number of tests taking place globally … is decreasing significantly,” said Van Kerkhove. “So our ability to track this virus — our ability to detect BA.2 — is compromised because testing is reduced and you can’t sequence the ones you don’t test.”
The significant decline in the number of tests worldwide is accompanied by many countries’ decisions to relax mitigation efforts, such as wearing masks and physical distancing. Many experts have noted that the combination of easing measures and declining protection against vaccination and boosters is fueling the spread of BA.2.
The US has yet to see an increase in cases related to BA.2. However, the rise in the number of cases in Europe is expected to foreshadow an increase in the states. And nearly 40 percent of wastewater monitoring stations in the US have already detected increases in SARS-CoV-2 levels. Wastewater monitoring picks up the virus excreted in the stool, which is one of the first signs of infection. The monitoring acts as an early warning system for increasing cases.
Experts don’t expect BA.2 to create a wave to rival that of BA.1 in January. However, the number of cases is expected to increase in the coming weeks, requiring continued vigilance.
On Tuesday, officials from the Biden administration made a plea to Congress for increased COVID-19 funding, including continued testing and oversight. Senior officials told reporters that without additional funding, testing capacity could be lost in June and surveillance efforts would be scaled back. “With diminished capacity to conduct adequate surveillance, the country will be prone to being ‘blinded’ by future variants,” the White House said in a summary of the fallout from the budget deficit. Administration officials also said they don’t have enough money to get an additional booster dose if fourth injections are widely recommended. Testing, access to therapies and worldwide vaccine donations would also suffer without more funding. The government is asking Congress for $22.5 billion.
