There has yet to be a variant the negates the benefits of vaccines.
Some scientists believe that a clearer picture of Covid vaccine efficacy could have emerged sooner if investigators had tracked certain immune cells, not just antibodies.
How to make Covid immunity even more durable.
Older people who received smallpox vaccinations may yet have some immunity, researchers say. Healthy children and adults generally do not become severely ill.
The puzzling coronavirus cases highlight ongoing surveillance challenges and blind spots.
The omicron subvariant BA.2.12.1 is poised to become dominant in the US, currently accounting for an estimated 36.5 percent of all US SARS-CoV-2 cases, according to the latest estimates released Tuesday by the Centers for Disease Control and Prevention.
The subvariant’s ascent is the latest rapid succession of omicron subvariants, from the sky-scraping peak of cases from the initial omicron subvariant BA.1 in January, to the current bump driven by the subvariant BA.2, which achieved dominance in March. As before, the reason for the viral usurping is that omicron subvariants continue to evolve advantages: BA.2.12.1 has a transmission advantage over BA.2, which had a transmission advantage over BA.1, which had a significant advantage over delta.
The imminent reign of BA.2.12.1 raises concern for yet another wave of infections and poses questions about how effective future omicron-specific vaccines could be against symptomatic infections.
Enduring an initial omicron infection may not spare you from omicron’s subvariants, according to preliminary data from South Africa.
The country is currently at the start of a new wave of infections, primarily driven by two omicron coronavirus subvariants, BA.4 and BA.5. Despite a towering wave of cases from the initial BA.1 omicron variant in December that infected a large chunk of the country, new omicron cases increased 259 percent in the last two weeks, according to data tracking by The New York Times. Hospitalizations are also up, and deaths have increased by 18 percent.
Preliminary data posted online last week helps explain why cases are once again surging—the BA.4 and BA.5 omicron subvariants can evade neutralizing antibodies generated by infections from BA.1. For the study, led by virologist Alex Sigal of the Africa Health Research Institute, researchers pitted neutralization antibodies from people infected with BA.1 up against BA.4 and BA.5 in a lab. They had samples from 24 unvaccinated people infected with BA.1 and 15 vaccinated people who had also had a BA.1 infection (eight people were vaccinated with the Pfizer/BioNTech vaccine, and seven had the Johnson & Johnson vaccine).
In a move highly anticipated by parents the country over, Moderna announced Thursday that it has requested FDA authorization for its two-dose COVID-19 vaccines for children 6 months to 2 years, and 2 years to under 6 years.
If the Food and Drug Administration issues an emergency use authorization (EUA) for the vaccines, they will be the first such vaccines available to the age groups in the now nearly two-and-a-half-year-long pandemic. Parents of young, vaccine-ineligible children have been anxiously awaiting the availability of such vaccines, particularly as much of the country tries to move on from the pandemic even as the number of cases of the extremely contagious omicron subvariants continue to tick upward.
“We are proud to share that we have initiated our EUA submission for authorization for our COVID-19 vaccine for young children,” Moderna CEO Stéphane Bancel said in a statement Thursday morning. “We believe mRNA-1273 [the COVID-19 vaccine] will be able to safely protect these children against SARS-CoV-2, which is so important in our continued fight against COVID-19 and will be especially welcomed by parents and caregivers.”
But prior infection does not guarantee protection from the virus, officials said, and Americans should still get vaccinated and boosted.
At least 75 percent of US children have now been infected with the pandemic coronavirus, up from roughly 44 percent before the omicron wave, according to a new study by the Centers for Disease Control and Prevention.
Children in the age groups of 0 to 11 and 12 to 17 have the highest infection rates and saw the most significant increases during the omicron wave compared with any other age group. About a third of all children in the country were newly infected during the omicron wave. Together, the data showcase just how poorly the country has done at shielding children—including those not yet eligible for vaccination—from the pandemic virus.
The new data dovetails with a study published by the CDC in February, which found that the peak rate of pediatric hospitalizations during the omicron wave was four times higher than the peak seen during the delta wave last fall. The largest increase was seen in children ages 0 to 4, who had a peak hospitalization rate five times higher than the peak amid delta.
The Alzheimer’s Association has pushed relentlessly to get broad access to Aduhelm, despite safety risks and uncertain evidence that it helps patients.
The mRNA-based COVID-19 vaccines made by Pfizer/BioNTech and Moderna have proven highly effective at priming our immune systems to fight the pandemic coronavirus—preventing substantial amounts of infection, severe disease, and death throughout several waves of variants. But, despite their similar design and efficacy, the two vaccines are not exactly the same—and our immune systems don’t respond to them in the same way.
An early hint of this was some real-world data that found startling differences in the effectiveness of the two vaccines, despite both shots performing nearly identically in Phase III clinical trials—95 percent and 94 percent. Amid last year’s delta wave, a Mayo Clinic study found that Pfizer’s effectiveness against infection dipped to 42 percent while Moderna’s only fell to 76 percent.
According to a new study in Science Translational Medicine, such differences might be explained by evidence that the two vaccines spur the immune system to produce slightly different antibodies against SARS-CoV-2.
So-called “natural immunity” against COVID-19 has always been a dodgy argument for avoiding vaccination during the pandemic. But amid omicron, natural immunity is clearly rubbish.
Unvaccinated people who have recovered from an infection with the omicron coronavirus variant are left with paltry levels of neutralizing antibodies against omicron and almost no neutralizing antibodies against any of five other coronavirus variants, including delta. People who were vaccinated before getting an omicron infection, on the other hand, have strong protection against all five variants, and they are among the highest levels of neutralizing antibodies seen against omicron.
That’s all according to a new study surveying neutralizing antibody profiles in people who have all recovered from an omicron infection, with or without pre-existing immunity. The study was published Wednesday in The New England Journal of Medicine by a team of Austrian researchers. The researchers were led by virologist Janine Kimpel of the Medical University of Innsbruck.
The coronavirus was expected to devastate the continent, but higher-income and better-prepared countries appear to have fared far worse.
Experts say that the most vulnerable would benefit from a second booster soonest.
Researchers in Atlanta have helped the federal government evaluate dozens of Covid tests and pioneer a new model for developing novel diagnostics.
The treatment could be lifesaving for many who cannot get protection from the vaccine, but confusion about the drug has made some doctors slow to prescribe it.
An estimated 140 million people in the US—around 43 percent—have had COVID-19, according to the latest analysis by the Centers for Disease Control and Prevention using data from the end of January.
The estimate of people infected with COVID-19 is nearly double the CDC’s cumulative tally of cases reported at the end of January, which totaled around 74 million. These numbers are expected to differ because many COVID-19 cases are not detected or reported—i.e., people may not get tested at all or take a home-test that is not reported. That means officials case counts are expected to be a significant undercount of actual infections. However, case reports can also include infections in people who have tested positive multiple times, effectively counting some people more than once.
The CDC has been estimating actual infections over time, which provides more insight into the recent tsunami of cases from the ultratransmissible omicron variant. Based on data from the end of November, the CDC estimates that about 37 million people became infected with the pandemic coronavirus in December and January. The number of cases reported to the CDC during that time frame was around 26 million.
The federal government has ordered 600,000 doses of the monoclonal antibody treatment, which is meant for high-risk Covid patients early in their illness.
A 90-minute walk, jog or bike ride after getting vaccinated may boost your body’s immune response.
White-tailed deer on Staten Island have become the first wild animals with documented Omicron infections. The coronavirus has now been found in deer in 15 states.
The immunity you gain after a Covid-19 infection might not be enough to fend off the virus again. Here’s what to know.
Nasal vaccines under development around the world may make better boosters by stopping the coronavirus in the airways.
Thirteen of Omicron’s mutations should have hurt the variant’s chances of survival. Instead, they worked together to make it thrive.
As Omicron cases skyrocket, more vaccinated people may get “hybrid” immunity after a breakthrough infection. But experts still encourage precautions.
Right from omicron’s first description, researchers were concerned about the variant of the SARS-CoV-2 virus. Looking over the list of mutations it carried, scientists could identify a number that would likely make the variant more infectious. Other mutations were even more worrying, as they would likely interfere with the immune system’s ability to recognize the virus, allowing it to pose a risk to those who had been vaccinated or suffered from previous infections.
Buried in the subtext of these worries was a clear implication: Scientists could simply look at the sequence of amino acids in the spike protein of a coronavirus and get a sense of how well the immune system would respond to it.
That knowledge is based on years of studying how the immune system operates, combined with a lot of specific information regarding its interactions with SARS-CoV-2. What follows is a description of these interactions, along with their implications for viral evolution and present and future variants.
Scarce supplies and surging Covid cases have caused health officials, hospitals, doctors and patients to scramble for pills and infusions.
People with compromised immune systems are getting unapproved fourth or fifth Covid-19 shots, despite uncertainty about their safety or effectiveness.
In the lab, antibodies produced during an Omicron infection protected against Delta. If Omicron dominates in the real world, that could lead to a less dire future.
The single remaining monoclonal antibody therapy effective against the variant is now in short supply in the U.S., imperiling an option that doctors and hospitals have relied on.
A 50-microgram dose increased antibodies by roughly 37-fold, and a full dose of 100 micrograms was even more powerful, the company said.
In the lab, immune cells put up a strong fight against Omicron, suggesting that vaccines will be able to prevent the worst outcomes of the virus variant.
The company’s finding is based on only a small study of blood samples in a laboratory, but others are sure to follow.
The first batch of preliminary laboratory data on the omicron coronavirus variant has come out, and the results are largely what health experts have anticipated: protective antibodies from two doses of the Pfizer-BioNTech vaccine are considerably less effective at thwarting the new variant than older versions of the virus. However, antibody potency appears to rebound to fight omicron after a booster dose.
The results suggest that people who have only two doses of the mRNA vaccine may not be protected from infection but would likely remain protected from severe disease. The findings also suggest that maintaining high levels of protection against omicron will require a booster dose of the current vaccines—or even an omicron-specific shot in the future.
The top-line findings and conclusions come from three separate sets of laboratory experiments—all of which are extremely preliminary, involve small sample numbers, and have not been peer-reviewed or published in scientific journals.
In a comparison of seven different brands, researchers found that most shots give a strong boost, even in mix-and-match combinations.
The treatment, known as molnupiravir, could be authorized in the United States within days, and available within weeks, if the F.D.A. follows the committee’s recommendation.
Intense research into the new coronavirus variant first identified in southern Africa, has just begun. World leaders have urged people not to panic — and to get vaccinated, if they can.
The pills must be given early in the course of infection, which means access to timely, accurate test results will be crucial.
The Omicron variant carries worrisome mutations that may let it evade antibodies, scientists said. But it will take more research to know how it fares against vaccinated people.
Federal scientists estimated that more than 40 percent of children aged 5 to 11 had been infected with the coronavirus by June. Outside experts aren’t so sure.
Experts strongly agree that the shots benefit the mother as well as the fetus.
The F.D.A. may authorize booster shots of vaccines different from the ones that Americans originally received. The science behind the move is promising.
Deaths among people who have been fully vaccinated remain rare, but older adults and those with compromised immune systems are at much higher risk.
Mixing and matching COVID-19 vaccines for booster doses appears safe and as effective—if not more effective—than sticking with the same vaccine for a booster dose. That’s according to preliminary data posted online Wednesday from a clinical trial run by the National Institutes of Health.
The trial bolsters what some have long hoped: that mixing and matching vaccines could provide stronger, broader protection against the pandemic virus and all its variants.
The trial was not large enough to definitively indicate which combination of vaccines offers the best protection. And the early results, available on a preprint server, have not yet been peer-reviewed. But the preliminary trial findings do hint that Moderna’s mRNA vaccine may offer the strongest protection all around—backing up similar findings from earlier vaccine-effectiveness studies. The data also suggests that people who received the one-shot Johnson & Johnson vaccine may want to get a boost with one of the two mRNA vaccines, either Moderna’s or Pfizer/BioNTech’s.
Viral evolution is a long game. Here’s where scientists think we could be headed.
So-called natural immunity varies from patient to patient, scientists say. Immunization is still the best choice after recovering from the disease.
As long as there have been vaccines against COVID-19, there have been arguments for why people shouldn’t get those vaccines. One of the more persistent—and hairier—arguments is that people who have already been infected with the pandemic coronavirus, SARS-CoV-2, don’t need a vaccine. An infection will generate immune responses similar to those generated by vaccines, the thinking goes. So, why waste coveted vaccine doses on people who already have immune responses against the virus—which may also needlessly put those people at risk of vaccine side effects, however rare?
It’s a reasonable question, and there is legitimate scientific debate about it. There are also different approaches to the issue in terms of public health policy. In Israel, for example, people who have recovered from COVID-19 after testing positive on a PCR test can get a vaccination “Green Pass” that’s valid for up to six months. The pass allows them entry into various places just as it does for people who are fully vaccinated. In the European Union, some member states offer a similar “Digital COVID Certificate” to people who have recovered from COVID-19 and received just one dose of a two-dose mRNA vaccine regimen.
In the US, however, public health officials are unequivocal in their approach: people are categorized as either vaccinated or unvaccinated, regardless of prior infection. It’s an approach with many strengths, including robust scientific data supporting vaccination for people who have recovered. That data—which we’ll get into below—has consistently shown that immune responses from natural infections are extremely variable, thus unreliable. Vaccines, on the other hand, have repeatedly proven to generate highly protective immune responses.
Championed by doctors and conservative radio hosts alike, monoclonal antibodies for Covid are in high demand — even from those who don’t want a vaccine.
Medical concierge services are offering coronavirus antibody tests as a perk, despite caveats about their usefulness.