Covid-19 Scrabbles in the USA and UK: Implications for vaccines, antiviral therapies, and immunocompromisation
In the United States, these are BQ.1, BQ.1.1, BF.7, BA.4.6, BA.2.75 and BA.2.75.2. In other countries, the recombinant variant XBB has been rising quickly and appears to be fueling a new wave of cases in Singapore. These variations have taken hold in Europe and the UK.
Dr. Peter Hotez, who co-directs the Center for Vaccine Development at Texas Children’s Hospital, says he thinks of them collectively as the Scrabble variants because they use letters that get high scores in the board game like Q, X and B.
As the US moves into the fall, Covid-19 cases are dropping. Normally, that would be a reason for hope that the nation could escape the surges of the past two pandemic winters. But virus experts fear that the downward trend may soon reverse itself, thanks to this gaggle of new variants.
According to the latest estimates from the Centers for Disease Control and Prevention, the Covid-19 variant accounted for almost 1 in 3 new infections nationwide last week.
The updated bivalent booster vaccines and antiviral drugs like Paxlovid are expected to continue to be protective against severe outcomes from Covid-19 infections caused by the new variants.
Crucially, some of the variants also appear to be impervious to the last lab-created antibodies available to ward off severe Covid-19 infections: an antibody treatment called bebtelovimab, which is made by Eli Lilly, and the combination of two long-acting antibodies in Evusheld, a shot made by AstraZeneca that helps keep people who are immunocompromised from getting sick in the first place.
Co-circulating Omicron Variants: Emerging Phases of Covid-19 Infections and Implications for Disease Control and Prevention
The Omicron family trees have differing branches but they share many of the same changes in their evolutionary makeup.
Some experts think this convergence means we’ve entered a new phase of the evolution of the virus, one that will see circulation of several variants at the same time.
“What is likely to happen is that we have several co-circulating, semi-dominate lineages going into the winter season,” said Nathan Grubaugh, an associate professor of epidemiology at the Yale School of Public Health.
“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 what is circulating has high fitness since the virus has adapted to human transmission.
Maria Van Kerkhove, a Covid-19 response technical lead for the World Health Organization, said Wednesday that the large mix of new variants was becoming more difficult for WHO to assess.
“So we need to be prepared for this. To deal with increases in cases, and possibly with increases and hospitalizations, a country needs to be in a good position. We don’t see a change in severity yet. And our vaccines remain effective, but we have to remain vigilant,” she said.
The Omicron BA.5 subvariant had dominated US Covid-19 infections since July, but a mix of other Omicron subvariants have been gaining against it. BA.5 now accounts for 49.6% of new infections in this country, according to data from the US Centers for Disease Control and Prevention.
Fauci told CNN that most people feel BA.5 will be bumped off as the dominant variant and that they will end up being a substantial proportion.
These variants are different from BA.4 and BA.5, but they’re descended from those viruses, the result of genetic drift. They share many of the same genes with that virus.
Their changes aren’t as big of a deal as when the original Omicron arrived. The strain of the virus that came out of genetic left field left researchers and public health officials scrambling to catch up.
Fauci said that the vaccine protection would not be as good if people were just to get the shot.
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. Less than 10% of the population are eligible to get one.
The Covid-19 Response against Vaccine Dominated Omicron B.4 and B.5 in Alzheimer’s Disease: How Well Will the Government Invest in Antibody Therapies?
“It’s probably going to be significantly bigger than the BA.5 wave, at least that’s what I expect,” said Mark Zeller, a project scientist who monitors variants at the Scripps Research Institute. But Zeller says he doesn’t expect this winter’s surge to reach heights of January’s Omicron wave.
The genetic changes these variants share appear to help them escape the immunity created by vaccines and past infections – a recipe for reinfections and breakthrough infections, particularly for people who haven’t had an updated booster.
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.
Jha said that it would take a long time to bring a monoclonal into the marketplace, regardless of whether or not they get money today.
The administration has been thinking about ways to commercialize some parts of the Covid-19 response – to get out of the business of buying vaccines and therapies – ultimately passing the costs on to consumers and insurers. The process must be guided by the needs on the ground and 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 researchers found that after either vaccine dose, 446 or 48% of participants reported systemic symptoms while 12% reported only local symptoms and 40% reported no symptoms at all.
The researchers write that the findings support reframing post-vaccination symptoms as signals of vaccine effectiveness and reinforce guidelines for vaccine boosters in older adults.
“I don’t want a patient to tell me that, ‘Golly, I didn’t get any reaction, my arm wasn’t sore, I didn’t have fever. The vaccine didn’t work.’ The director of the National Foundation for Infectious Diseases is not involved in the new study and he wants it to be out there.
In 444 of the people with symptoms, 98% were found to have no symptoms, while 99% of those with symptoms had only local symptoms and 99% had systemic symptoms.
According to Pfizer and BioNTech, the immune response against Omicron ba.4/BA.5 subvariants was substantially higher in people who received the company’s original Covid-19 vaccine.
As we head into the holiday season, we hope the updated data will encourage people to take advantage of a COVID-19 bivalent booster as soon as they are eligible for it in order to maintain high levels of protection against the Omicron BA.4 and BA.5 sublineages. The updated data shows us how to rapidly update our vaccine to match the most prevalent strains, which is a confidence in the ability of our platform.
The updated boosters are still being tested in large clinical trials by Pfizer and BioNTech.
Experts say getting boosted this fall is still an important way to renew protection, even among people who were previously infected or vaccinated. People who are 5 years old are eligible for updated boosters.