As the omicron variant of SARS-CoV-2 took hold across the globe in late 2021, it became readily apparent that the pandemic had entered a new phase. Having experienced a previous COVID-19 infection or being vaccinated still left many people wondering how vulnerable they were to the virus.

Some 4.9 billion people – or 63.9% of the world’s population – have received at least one dose of the COVID-19 vaccine as of late February 2022. And more than 430 million cases of COVID-19 have been confirmed since the start of the pandemic.

So with the majority of the world population being either immunized against COVID-19 or having recovered from infection, people have rightly begun to ask: How long will the immunity triggered by either vaccination, an active infection or a combination of both provide immune protection?

This is a challenging question because the virus is relatively new and novel variants have continuously emerged. However, researchers are beginning to better understand how existing immunity protects against reinfection and the prevention of severe COVID-19 that can lead to hospitalization and death.

Read more at The Conversation.

A new report from a broad range of disinformation experts finds influencers across many topics — wellness, politics and religion — were largely responsible for spreading viral anti-vaccination content in the U.S. over the past two years.

Why it matters: Influencers with large followings often introduced new and personal angles to familiar anti-vax tropes, making it difficult for social media companies to moderate their comments without running into free speech issues.

Details: The report from the Stanford Internet Observatory, Graphika and several universities and institutes, found that the same subset of recurring actors, including political leaders and celebrities, were often the ones most effective at spreading misinformation widely.

Read more at Axios.

The US has a booster problem. Less than half of all American adults — 42 percent — say they have received an additional dose of a Covid-19 vaccine, according to the most recent Kaiser Family Foundation survey. Among vaccinated people, that share is 70 percent. Better but a long way from ideal.

That is in spite of evidence that an additional dose provided more protection against the omicron variant. Even among all Americans over 65 years old, the group most likely to see a drop in effectiveness from the initial two doses, the percentage that’s received booster shot is 66 percent. The US vaccination campaign is now trailing far behind our peers in the United Kingdom, where more than 85 percent of people over 65 have gotten their booster.

As Sarah Zhang wrote in the Atlantic earlier this month, the most obvious pandemic strategy for the US going forward is to vaccinate and boost more people, especially the elderly who are most at risk. Eric Topol, the director of the Scripps Research Translational Institute, said the lagging booster rate “has been one of the most serious disappointments” in the US response.

But why has it been such a struggle? Digging into the KFF polling data, it appears the United States has two distinct challenges in boosting more people.

Read more at Vox.

The rapid spread of omicron across the nation — and the finding that vaccines continue to provide strong protection against severe disease — brings COVID-19 one step closer, perhaps, to truly earning its place on the list of diseases that have been tamed by vaccines. These include polio, measles, mumps, rubella, and chickenpox, all of which most kids must generally be vaccinated against before they enter school or day care. Some states have announced COVID-19 vaccine requirements for certain students.

But not everyone agrees that vaccine mandates for children are the way forward. Sen. Rand Paul, who has opposed vaccine mandates, called omicron “nature’s vaccine.” Seventeen mostly Republican-led states have proactively banned, in some form, COVID-19 vaccine requirements for students. Resistance to adopt mandates has profound repercussions, especially as vaccination rates among kids ages 5 to 11 remain alarmingly low — under 15 percent in some states — even though children 5 and over have been eligible for shots since last fall.

History holds lessons for why low vaccination rates for children are so risky and why officials should strongly consider school mandates for the COVID-19 vaccine.

Read more at Tampa Bay Times.

The interval between first and second doses of the Pfizer and Moderna Covid-19 vaccines may be as long as eight weeks for certain people, the US Centers for Disease Control and Prevention said in vaccine guidance updated Tuesday.

Previous guidance said the second doses should be administered three weeks after the first shot of the Pfizer vaccine or four weeks after the first shot of the Moderna vaccine.

The vaccines remain safe and effective at their original intervals, the CDC said, but extending the interval may reduce the risk of myocarditis, a type of heart inflammation, in some populations. Rare cases of myocarditis have been reported primarily after the second dose of mRNA Covid-19 vaccines, and males ages 12 to 29 are at highest risk.

“While absolute risk remains small, the relative risk for myocarditis is higher for males ages 12-39 years, and this risk might be reduced by extending the interval between the first and second dose,” the CDC said, noting that some studies in people older than 12 have shown “the small risk of myocarditis associated with mRNA COVID-19 vaccines might be reduced and peak antibody responses and vaccine effectiveness may be increased with an interval longer than 4 weeks.”

Read more at CNN.

Experts worry a lack of data may be obscuring where to target strategies for vaccinating kids of color, who disproportionately suffer severe illness from COVID-19 but may lack access to the shot.

Just shy of a third of children ages 5 to 11 nationwide have received at least one dose of COVID-19 vaccine and a quarter are fully vaccinated, Centers for Disease Control and Prevention data shows.About 67% of kids 12 and older have received one dose, and only 57% are fully vaccinated.

But the CDC does not report children’s COVID-19 vaccination rates by race, and inconsistencies and variations remain in the ways figures are broken down and reported from state to state.

The Kaiser Family Foundation reports only seven states are releasing kids’ vaccination data by race in a way that allows for statistical comparison. Among those states, Black children generally trailed behind white children, with rates of kids from other racial groups varying.

Read more at USA Today.

On February 17, 2022, the updated Recommended Childhood and Adolescent Immunization Schedule was released by the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention. Pediatric providers across the country eagerly await this annual update to learn what changes lie in store for recommended immunization practices. During the week that has gone by since the 2022 release, I’ve had a chance to reflect on some of the highlights that are worth noting.

The SARS-CoV-2 (COVID-19) vaccines are not on the schedule yet, undoubtedly because of the preliminary nature of the vaccine data for children and the emergency use authorization vaccine status.

Read more at Medscape.

Why a fourth shot is — or isn’t — necessary

At this point, one thing about the pandemic is clear: The COVID-19 vaccines, even when followed by a booster, aren’t going to stop the coronavirus — or provide long-term protection from infections.

Right after the third shot — the booster — antibodies rise up quickly. But then about a month later, they begin to decline. As a result, protection against infection drops down to about 50% three months later.

So the question is: Should you get a fourth dose to beef up protection again?

A preliminary study from Israel, published last Tuesday, suggests that for the general population, the answer is likely no. A fourth shot of the same vaccine — in this case Pfizer-BioNTech or Moderna — offered very little extra protection against infection compared with only three shots.

“Not a third dose, not a fourth dose, not a fifth dose will do anything to stop infections [long term],” says Dr. Gili Regev-Yochay, an infectious disease specialist at Sheba Medical Center in Tel HaShomer, Israel, and lead author of the new study.

Read more at NPR.

With every twist and turn of the COVID-19 pandemic, journalists, governments, policymakers and researchers have increasingly used the term ‘vaccine hesitancy’ to account for why so many people remain unvaccinated even in nations where supplies are plentiful. The share of papers with ‘vaccine’ or ‘vaccination’ in the title that also mention ‘hesitancy’ rose from 3.3% in 2019 to 8.3% in 2021 (see ‘The power of words’), according to a Web of Science search.

The most striking lesson from the pandemic is that preoccupation with vaccine hesitancy — whatever that term might mean to different people — centres too much of the responsibility for the success (or not) of a vaccination programme on individuals.

It is mainly governments that have the power to make vaccines both accessible and acceptable. Before the COVID-19 vaccine roll-out, a survey indicated that people living in Chile were more reluctant to get vaccinated than were those in other Latin American countries¹. Yet more than 89% of Chile’s population has been fully vaccinated, as defined by that nation. And an early analysis indicates that this is largely thanks to vaccination being prioritized politically². In a pre-pandemic example, Australia’s federal government started to introduce various improvements to childhood immunization programmes in 1997, including financial incentives for parents and doctors. Childhood vaccination rates rose from around 84% to 94% within three years³³.

Read more at Nature.

Veteran Fox Business host Neil Cavuto’s extended, unexplained absence from the network over the past five weeks has raised questions for many viewers — some wondered whether something sinister was afoot, others feared he had suddenly died.

Upon returning to his show Cavuto: Coast to Coast on Monday, the anchor said the latter guess was nearly correct: A second bout of COVID-19 landed him in the intensive care unit, where he said things were “touch and go” for some time.

Cavuto, who has multiple sclerosis and survived stage 4 cancer and open-heart surgery, counted himself among the roughly 3% of Americans who has a weakened immune system and “cannot sustain the full benefits” of the COVID-19 vaccine. But he said some defense was better than no defense.

“Let me be clear,” he told viewers. “Doctors say had I not been vaccinated at all, I wouldn’t be here.”

Read more at NPR.