Vaccines for Covid-19 in the United States and Europe, and the Emergence of New Variants in the U.S.
In the US, they are BQ.1, BQ.1.2, BA.5 and BA.2.50. The XBB variant in Singapore has been rising quickly, and appears to be fueling a new wave of cases. Cases are also rising in Europe and the UK, where these variants have taken hold.
Dr. Peter Hotez, co-direct of the Center for Vaccine Development at Texas Children’s Hospital, says that they are similar to the Scrabble variant because they use letters that get high scores in the board game.
It is not known whether the number of flu cases in North America will go up throughout December and January, creating a larger than normal disease burden, or if the epidemic starts to decline earlier than usual.
According to the latest estimates from the US Centers for Disease Control and Prevention, the variant accounted for almost one in three new Covid-19 infections nationwide last week.
The original strain of the coronaviruses and the BA.4 and BA.5 subvariants can be protected with the bivalent booster vaccine.
The last lab created antibodies can be used to prevent severe Covid-19 infections, but some of the variants are impervious to them.
Though they each descend from slightly different branches of the Omicron family tree, these new offshoots have evolved to share many of the same mutations, a phenomenon known as convergent evolution.
2020 was the year of Covid lockdowns, 2021 the year of vaccines, and 2022 the year of worldwide reopening. 2023 will be the year of variant prediction. There were different Covid variant of concern and they all caused confusion as to where the epidemic would go next. Alpha was better at transmitting thanBeta was better at evading immunity. What would the longer-term pattern of evolution look like?
Nathan Grubaugh, an associate professor at the Yale School of Public Health, believes that there are several co-circulating, semi-dominate lineages going into the winter season.
“That’s because with convergent evolution, perhaps several different lineages can independently obtain similar transmissibility levels versus a single new variant taking over.
“This is what predominantly happens for most pathogens, such as the flu and RSV,” Grubaugh wrote in an email. Most of the stuff circulating has a high level of fitness since the virus has adapted well to human transmission.
The U.S. Omicron Varying-Bayes Epidemics and Influence on the Disease: What Have We Learned in the Last Three Months?
The large mix of new variant was becoming more difficult for the World Health Organization to assess because countries were dialing back on their surveillance, Maria Van Kershove said Wednesday.
“So we need to be prepared for this. There are certain things a country needs to be in a position to conduct, such as trying to deal with increases in cases and hospitalizations. A change in severity hasn’t been seen yet. And our vaccines remain effective, but we have to remain vigilant,” she said.
For now, the Omicron subvariant BA.5 still holds the top spot in the US. According to CDC estimates, it caused about 68% of new infections in the US last week, but it is quickly being outcompeted by several new sublineages – notably BQ.1 and BQ.1.1.
“The projections vary a little, but generally, most people feel somewhere in the middle of November that they’ll wind up being a substantial proportion and have bumped BA.5 off as the dominant variant,” Fauci told CNN.
These variations are not the same as BA.4 or BA.5, but they are descended from thoseviruses, the result of genetic drift. They share parts of their genomes with that virus.
In 2022, the Omicron BA.1 variant caused large epidemics. This led to an accumulation of immunity within populations, followed by declining transmission, only for a new subvariant, BA.2, to emerge, against which this immunity was less effective. There were epidemics that followed and the cycle started again in mid-2022.
If people just got the shot, Fauci said it would be different because it would escape protection from vaccine.
According to the latest data from the CDC, 14.8 million people have gotten an updated bivalent booster six weeks into the campaign promoting it. That’s less than 10% of the population that’s eligible to get one.
Is the flu season coming to an end this year? The impact of Covid-19 antibody therapies on vaccines, disease and age: A CNN interview with Mark Zeller
Mark Zeller, a project scientist at the Scripps Research Institute said that it was likely that it would be considerably bigger than the BA.5 wave. He doesn’t think this winter’s surge will reach heights of January’s Omicron wave.
The genes that are shared appear to help them escape the immunity created by vaccines and past infections, meaning people who haven’t had an updated booster are at greater risk of getting infections.
But antibody therapies are particularly important for people with immune function that has been blunted by drugs, disease or age. These are the same people whose bodies don’t respond robustly to vaccines.
“So even if we got money today, it would take us many months to bring a monoclonal into the marketplace, and we don’t have the money today anyway,” Jha told CNN.
The administration is looking at ways to make it so that the parts of the Covid-19 response that are approved are used to make drugs for people instead of being used for vaccine and therapy. But Jha says the process has to be guided by “the needs on the ground and the realities of the virus.”
He says current realities require that the government continue to incentivize the production of new therapies, and he expects that the Biden administration will again try to ask Congress to pass more funding to do that.
The rate of hospitalizations for children for seasonal flu is more than ten times the normal rate for this time of the year, and clinics and parents are watching with concern. In late November, weekly admissions were 50% higher than at the peak for at least seven flu seasons.
A(H3N2) is also more severe than other common strains: it has caused more than twice as many hospitalizations over the past six flu seasons as another common subtype, A(H1N1), which caused the 2009 ‘swine flu’ pandemic. The 2017–18 US flu season — the country’s worst for more than a decade — was also dominated by A(H3N2). This resulted in 710,000 hospitalizations and 52,000 deaths in the United States, including more than 500 children.
Seasonal flu typically kills about 389,000 people globally each year, and its impact is most severe in people over 65 years of age, followed by very young children and people who are immunocompromised.
The flu season in 2022–23 is shaping up to be more severe in the Northern Hemisphere. In North America in particular, cases have risen sharply since October, kicking off an unusual, month-early start to the flu season in both Canada and the United States.
When it comes to selecting influenza vaccines, teams use a range of data, from the growth rates of circulating variants in genomic data to tests of their immunological properties. An additional complication is variability in what different populations have previously been exposed to. Some countries have more immunity than others, and so can have more advantages over those that don’t. The influenza viruses are dominant in different continents and countries.
If this evolutionary trajectory continues, we’ll see this cyclic pattern in 2023 and beyond. It is a similar phenomenon to the seasonal coronaviruses that have caused epidemics in the past. A 2021 study by researchers at Fred Hutchinson Cancer Research Center found that coronaviruses gradually evolve over time, so prior immunity is less effective.
Further into the future, there is hope for progress on “universal” coronavirus vaccines, which will be highly effective against a wide range of variants. Despite the history of development for other universal vaccines, success is not guaranteed. As a result, the coming year will be the start of a long game of cat-and-mouse, pitting vaccine updates against an evolving virus. The vaccine roll out will be one of the major health challenges of the year.