In the United States, a new version of the omicron is in dominant position
According to the Centers for Disease Control and Prevention, nearly 54% of all Covid cases in the country were caused by the coronavirus subvariant BA.5. BA.4, a subvariant similar to BA.5, makes up 17%.
David Montefiori, a Duke University Medical Center professor, said that "they're takingover, so clearly, they're more contagious then earlier variants of omicron,".
These two subvariants appear to be more able to evade vaccines and other infections than their predecessors.
Montefiori found that BA.4 (and BA.5) are three times more sensitive to neutralizing antibodies from Covid vaccines than BA.1. Research also suggests that BA.4/BA.5 is four times more resistant than BA.2, the U.S. dominant coronavirus variant, which was replaced by the omicron version in April.
Francois Balloux is the director of University College London Genetics Institute. He said that it's likely another reason why the subvariants have overtaken.
He said that he believes all variants are nearly equally transmissible at this point. It's only that some variants are slightly more effective at infecting people who have been vaccinated against or infected with previous variants.
Last week, the Food and Drug Administration recommended that booster shots from Moderna and Pfizer be modified to directly target BA.4 and BA.5.
Pfizer told NBC News it may have an updated vaccine that targets BA.4 or BA.5 available for distribution in October.
The most common Covid symptoms in the U.K. last week were runny nasal, persistent cough, headache and fatigue. According to the Zoe COVID Study data, less than one third of respondents reported having fevers. This study asks people to report their symptoms via smartphone apps.
This is consistent with symptoms that were reported in the U.K. during spring when the BA.2 subvariant was predominant.
Balloux stated that there has not been any difference in symptoms between the BA.4 and BA.5 subvariants. However, people who have been infected by the original omicron variant of the virus during winter could be more susceptible to the latest subvariants.
He said that BA.1 and BA.2 were very different, and cross-protection was "not as great."
Balloux said, however, that B.2, BA.4 or B.5 are interchangeable from a neutralizing antibodies perspective. This could mean that those who have had BA.2 infections may be protected now.
Montefiori stated that BA.4 as well as BA.5 have not been shown to cause more severe diseases.
He stated that there is no evidence to suggest that these drugs are more or less likely than others to cause serious illness and death.
Instead, the rise in hospitalizations and cases in certain areas may be due to fading vaccine protection.
Montefiori stated that "we have waning immunity now among the people who got boosted half an year ago or more."
According to the FDA, omicron-specific boosters by Moderna and Pfizer will be available in the early or mid-fall.
Montefiori stated that "The companies are now scrambling to make the BA.4/BA.5 vaccine and test it clinically."
Experts stressed that there might not be much difference in protection between omicron-specific shots and additional boosters of current vaccines. Current vaccines are still effective in preventing severe illness and death.
Montefiori stated that the virus is moving in the direction of escaping vaccines more and faster, but has yet to find a way out to vaccines to a significant extent.
He said that people who are eligible for second boosters, such as those over 50 and the immunocompromised, may not want to wait.
Montefiori stated that if your last booster was more than six months ago, it might be worth considering getting a boost now to ensure your protection while we are still fighting this pandemic.
Balloux stated that it is difficult to predict whether BA.5 will be still dominant in the future.
He said, "Given uncertainty, there's not any right or wrong." "There are only tradeoffs."
The reported Covid cases in the United States have remained relatively stable since May, however, global case numbers are increasing.
The World Health Organization reported that new weekly cases had increased by 32% in Southeast Asia, 33% for Europe, and 47% in the Horn of Africa region, which includes the Middle East, Central Asia and North Africa. BA.5 was responsible for 43% of all omicron cases in the world, while BA.4 had 12%.
South Africa saw an increase in cases due to BA.4/BA.5 this spring. In the U.K., Covid hospitalizations have been on the rise. Experts believe that these trends indicate that the virus is improving at reinfecting people, and evading vaccine protection.
The future of the pandemic depends on more than the properties of the variants. It also depends on how the population behaves and how immune they are.
Balloux stated that people tend to underestimate how much the virus changed in recent years. "There was a huge, huge change between delta, omicron and then again between BA.1 & BA.2.
He said that this is not the case for BA.4 or BA.5, but he did note another significant shift in the virus’s evolution.
He said, "I'm certainly not saying it won’t happen."
