Vaccine protection against severe outcomes from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) lasts at least six months after the second dose, but protection is lower for older patients, according to a study published online Feb. 3 in JAMA Network Open.

Yuchen Wei, Ph.D., from the Chinese University of Hong Kong, and colleagues examined the change in vaccine effectiveness against hospitalization and mortality due to the omicron variant in a case-control study involving adults with SARS-CoV-2 omicron variant infection who died or were hospitalized from Jan. 1 to June 5, 2022 (32,823 case participants) and propensity score-matched adults with SARS-CoV-2 omicron (131,328 control participants).

The researchers found that for at least six months after the second dose of both the CoronaVac and BNT162b2 vaccines, vaccine effectiveness against death or hospitalization was maintained (74.0 and 77.4 percent, respectively). In those aged 18 to 49 years, vaccine effectiveness against death was 86.4 and 92.9 percent for those receiving two doses of CoronaVac and BNT162b2, respectively, while for patients aged 80 years and older, vaccine effectiveness decreased to 61.4 and 52.7 percent, respectively. At four to six months after the third dose, overall vaccine effectiveness against death was >90 percent for CoronaVac, BNT162b2, and the mixed vaccine schedule.

“A booster dose is recommended for older individuals to restore immunity,” the authors write. “This is especially critical in a setting like Hong Kong, where coverage of the third dose of the vaccine is still insufficient among older residents.”

One author disclosed financial ties to Beth Bioinformatics.

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Introduction of a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination during pregnancy can protect the youngest infants from pertussis, according to a study published online Feb. 6 in JAMA Pediatrics.

Tami H. Skoff, from the U.S. Centers for Disease Control and Prevention in Atlanta, and colleagues calculated and compared pertussis incidence rates in the pre-maternal Tdap vaccination period (2000 to 2010) and the post-maternal Tdap vaccination period (2012 to 2019) for infants younger than 2 months (target group of maternal vaccination) and infants age 6 to less than 12 months (comparison group).

The researchers found that in the pre-maternal Tdap vaccination period, annual pertussis incidence did not change among infants aged younger than 2 months and increased slightly among older infants, with no change in the difference in incidence seen between the two age groups. In the post-maternal Tdap vaccination period, there was a decrease in incidence observed among infants younger than 2 months (slope, −14.53 per 100,000 infants per year), while no change was seen for older infants (slope, 1.42 per 100,000 infants per year). During the post-maternal Tdap vaccination period, the incidence rate difference between the two age groups decreased significantly (slope, −14.43 per 100,000 infants per year). Between the pre- and post-maternal Tdap vaccination periods, pertussis incidence rate differences were significantly different (slope difference, −14.51 per 100,000 infants per year).

“Our data suggest that maternal Tdap vaccination is associated with a reduction in disease burden among the youngest and most vulnerable age group (

More information:
Tami H. Skoff et al, US Infant Pertussis Incidence Trends Before and After Implementation of the Maternal Tetanus, Diphtheria, and Pertussis Vaccine, JAMA Pediatrics (2023). DOI: 10.1001/jamapediatrics.2022.5689

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An international research team has provided one of the first real-world estimates of vaccine effectiveness against omicron infections, irrespective of symptoms or severity. From a serological survey of 5,310 blood donors and other volunteers, the researchers estimated that three doses of the Comirnaty or CoronaVac vaccines were, respectively, 48% or 30% effective in preventing omicron infection shortly after vaccination, further improving shortly after a fourth dose.

The researchers expected protection from infection also relates to protection from transmission, and this is one of the first reports suggesting vaccine-induced protection from omicron virus transmission. However, vaccine effectiveness waned rapidly thereafter over 100 days. Moreover, the researchers estimated that more than 45% of the Hong Kong population was infected between 1 January and 31 July 2022. These findings have been published in Nature Medicine.

The SARS-CoV-2 omicron variant has demonstrated enhanced transmissibility and escape of vaccine-derived immunity. Between 1 January to 31 July 2022, Hong Kong experienced an unprecedented fifth wave of COVID-19 infections driven predominantly by the omicron BA.2 subvariant. As local COVID transmission before 2022 was minimal, population immunity to SARS-CoV-2 in Hong Kong was almost entirely vaccine-derived at the start of the wave.

There is extensive data on how COVID-19 vaccines robustly prevent severe disease, hospitalization and death. However, few studies have investigated their effectiveness in preventing omicron infections, irrespective of symptoms or severity. Prevention of infection itself indicates prevention of both asymptomatic and symptomatic disease transmission.

Combining results from a community-wide serological survey of 5,310 blood donors and volunteers with SARS-CoV-2 viral load data from city-wide wastewater surveillance, the researchers estimated, (i) vaccine effectiveness against all omicron BA.2 infections conferred by two, three and four homologous doses of the Comirnaty or CoronaVac vaccines for 100 days after each dose and (ii) COVID-19 infection attack rate in Hong Kong from 1 January to 31 July 2022. The researchers developed two in-house ELISA assays detecting IgG antibodies to the nucleocapsid (N) or Open Reading Frame 8 (ORF8) protein of SARS-CoV-2, with the latter assay developed specifically to detect past infection in CoronaVac vaccines.

The researchers estimated three and four doses of Comirnaty were 48% and 69% effective in preventing omicron infection, respectively, seven days after vaccination, waning to 26% and 35% by 100 days after vaccination. Three and four doses of CoronaVac were 30% and 56% effective after seven days respectively, declining to 6% and 11% by 100 days.

Meanwhile, the researchers identified that more than 45% of the local population in Hong Kong was infected by SARS-CoV-2 between 1 January and 31 July 2022 (i.e., an infection attack rate of 45%). Accordingly, official case counts, incorporating both Reverse Transcriptase-PCR (RT-PCR) testing and Rapid Antigen Testing (RAT) results, identified less than 41% of all infections.

The results indicate that booster vaccination using either the mRNA or inactivated vaccine platforms is effective in preventing SARS-CoV-2 omicron BA.2 infection in the short-term. This adds to previous studies demonstrating robust vaccine effectiveness in preventing severe disease and death.

Thus, surge booster campaigns, particularly with updated bivalent mRNA vaccines, could be strategically used to rapidly boost population immunity when there is risk of future waves of infections arising from a concerning novel virus variant. The comparatively lower infection attack rate in Hong Kong by July 2022, versus various overseas jurisdictions, highlights the effect of supplementing vaccination campaigns with continued public health and social measures (e.g., masking) on reducing disease transmission.

The University of Hong Kong

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New York City, which once had the nation’s strictest workplace vaccination rules for COVID-19, is ending one of its last such mandates, saying it will no longer require the shots for municipal employees including police officers, firefighters and teachers.

The vaccine mandate, which led to the firing of hundreds of city workers who declined to get the shots, will end Friday, Mayor Eric Adams announced Monday.

Adams, a Democrat, said that with more than 96% of city employees and more than 80% of city residents having received their initial vaccine series, “this is the right moment for this decision.”

City Health Commissioner Dr. Ashwin Vasan said, “It’s clear these mandates saved lives and were absolutely necessary to meet the moment. We’re grateful that we can now, as we leave the emergency phase of the pandemic, modify more of the rules that have gotten us to this point.”

The vaccination mandate for city employees was one of the last COVID-19 measures still in place in New York City. The city ended its vaccine requirement for employees of private businesses in November 2022, and masks are now optional in most public spaces including subways and buses.

New York City’s private-sector mandate forced All-Star point guard and vaccine skeptic Kyrie Irving to miss most of the Brooklyn Nets home games last season.

Irving will no longer be affected by any changes in New York City’s coronavirus policies. The Nets and the Dallas Mavericks announced a deal Monday that will send Irving to Dallas.

New York City’s municipal work force of about 337,000 was one of the largest groups of government employees in the United States to be affected by a COVID-19 vaccine mandate.

The vaccine requirement for the 1.3 million-strong U.S. military was lifted in December under an $858 billion defense spending bill passed by Congress and signed into law by President Joe Biden.

The approximately 1,780 New York City workers who have been terminated for failing to comply with the municipal employee vaccination requirement will not get their jobs back automatically but can apply for positions with their former agencies, city officials said.

Unions representing some of the fired workers planned a news conference later Monday to demand their reinstatement with back pay.

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Children in California won’t have to get the coronavirus vaccine to attend schools, state public health officials confirmed Friday, ending one of the last major restrictions of the pandemic in the nation’s most populous state.

Gov. Gavin Newsom first announced the policy in 2021, saying it would eventually apply to all of California’s 6.7 million public and private schoolchildren.

But since then, the crisis first caused by a mysterious virus in late 2019 has mostly receded from public consciousness. COVID-19 is still widespread, but the availability of multiple vaccines has lessened the viruses’ effects for many—offering relief to what had been an overwhelmed public health system.

Nearly all of the pandemic restrictions put in place by Newsom have been lifted, and he won’t be able to issue any new ones after Feb. 28 when the state’s coronavirus emergency declaration officially ends.

One of the last remaining questions was what would happen to the state’s vaccine mandate for schoolchildren, a policy that came from the California Department of Public Health and was not impacted by the lifting of the emergency declaration.

Friday, the Department of Public Health confirmed it was backing off its original plan.

“CDPH is not currently exploring emergency rulemaking to add COVID-19 to the list of required school vaccinations, but we continue to strongly recommend COVID-19 immunization for students and staff to keep everyone safer in the classroom,” the department said in a statement. “Any changes to required K-12 immunizations are properly addressed through the legislative process.”

The announcement was welcome news for Jonathan Zachreson, a father of three who lives in Roseville. Zachreson founded the group Reopen California Schools to oppose many of the state’s coronavirus policies. His activism led to him being elected to the Roseville City School District board in November.

“This is long overdue. … A lot of families have been stressed from this decision and worried about it for quite some time,” he said. “I wish CDPH would make a bigger statement publicly or Newsom would make a public statement … to let families know and school districts know that this is no longer going to be an issue for them.”

Representatives for Newsom did not respond to an email requesting comment.

California has had lots of influence over the country’s pandemic policies. It was the first state to issue a statewide stay-at-home order—and other states were swift to follow.

But most states did not follow California’s lead when it came to the vaccine mandate for public schools. Officials in Louisiana announced a similar mandate, but later backed off. Schools in the District of Columbia plan to require the COVID-19 vaccine starting in the fall.

Republican U.S. Rep. Kevin Kiley, a former member of the state Assembly who challenged Newsom in a failed recall attempt in 2021 over his pandemic policies, published a blog post declaring: “We won. To Gavin Newsom: You lost.”

Kevin Gordon, a lobbyist representing most of the state’s school districts, said he did not think the policy change was the result of political pressure by Republicans, but instead a reflection of the virus’s slowing transmission rates.

“The public’s appetite for these kinds of mandates is definitely not what it used to be,” he said. “If you started to now impose a heavy mandate when the amount of transmission is significantly lower than it was statewide, a one-size-fits-all solution doesn’t work right now.”

© 2023 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.

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By taking inspiration from the evolutionary history of SARS-CoV-2 itself, scientists in China have crafted a new vaccine that, at least in animal models, provides protection against omicron and an array of its subvariants.

Even though early generations of SARS-CoV-2 vaccines and boosters have been extremely successful, viral evolution and the emergence of immune evasion have made subsequent vaccines more difficult to produce. Vaccinologists are constantly asking: How do we keep up with the rapidly evolving pathogen? The coronavirus always seems several steps ahead, especially now as omicron subvariants continue to evolve keener capacities of immune escape.

Despite the invaluable tools that mRNA vaccines have become over the past two years, more vaccine approaches are needed, scientists say.

As it turns out, the viral spike protein has regions that have remained highly conserved across recent SARS-CoV-2 variants. These conserved regions are veritable catalogs of evolutionary data with which to craft a next-generation vaccine. The spike protein is the business end of the virus that binds to human ACE-2 receptors to initiate infection.

To address the critical problem of immune escape and to begin the arduous task of developing a new vaccine, Dr. Yongliang Zhao and colleagues at State Key Laboratory of Virology, a division of Wuhan University in China, hope to blunt the impact of subvariants in the future with a new kind of vaccine.

The experimental vaccine they are already testing in lab mice is based on conserved regions of the spike protein, which means the vaccine is intimately linked to parts of the spike that rarely mutate.

The Wuhan team is quietly voicing optimism about their research, which they hope will serve as a model for future vaccines, a pan-protective immunization—a universal shot that guards against existing variants and threats that may arise in the future. A key concern with current vaccines is that while they protect against severe disease, newer versions of the virus, such as omicron’s growing multitude of subvariants, can slip past the immune system’s defenses.

Zhao and a team of collaborators from several Wuhan research institutions began development of the new vaccine by interrogating the evolutionary trajectory of SARS-CoV-2. As a critical part of their research, they analyzed more than 11 million SARS-CoV-2 sequences, as well as the infectivity and immune escape ability of 54 SARS-CoV-2 pseudoviruses and variants.

The experiments revealed that the viral spike protein hasn’t evolved randomly but rather towards either high infectivity paired with low immune escape or low infectivity paired with high immune escape.

Based on this, the team designed a vaccine centered on a newly engineered antigen named Span. The letter “S” in the name stands for “spike,” as in the viral spike protein, and “pan” is from the Greek word meaning “all,” referring to a vaccine against all spike proteins. Looking at the term pan another way, combining it with a version of the Greek word demos, which means people, you get “pandemic,” a disease that affects all people.

Developing the investigational Span vaccine hasn’t been easy, Zhao and colleagues write in the journal Science Translational Medicine. “SARS-CoV-2 continues to accumulate mutations to evade immunity, leading to breakthrough infections after vaccination,” asserted Zhao, lead author of the Span vaccine research.

“How researchers anticipate the evolutionary trajectory of the virus in advance in the design of next-generation vaccines requires investigation,” Zhao continued. “Here, we performed a comprehensive study of 11,650,487 SARS-CoV-2 sequences, which revealed that the SARS-CoV-2 spike protein evolved not randomly but into directional paths of either high infectivity plus low immune resistance or low infectivity plus high immune resistance.”

The Span antigen incorporates amino acid residues found at a high frequency across all major variants to date, allowing it to protect against evolutionarily divergent lineages. The Span vaccine so far has prompted neutralizing antibodies against various SARS-CoV-2 variants when the vaccine is administered to animal models in the laboratory.

Zhao and collaborators tested the innovative Span vaccine alongside a vaccine made from a wildtype spike protein that lacked the evolutionary dowry of Span. The researchers found that the immune response was more potent after Span vaccination than shots based on the wildtype spike protein. Animal models—in this case, mice—were completely protected from omicron variants when administered shots of the Span vaccine.

The Wuhan team, according to Zhao, needs to conduct additional tests of the vaccine’s effectiveness against more recent omicron subvariants, particularly those that have emerged in recent months. The researchers also caution that Span inoculations require more testing in animal models other than lab mice to best understand the vaccine’s strengths and weaknesses. “It will be essential to include additional animal models before translating this vaccine to [human] clinical trials,” Zhao concluded.

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An experimental vaccine for Marburg virus—a deadly cousin of the infectious agent that causes Ebola—can protect large animals from severe infections for up to a year with a single shot, scientists have found in a new study.

Developed by the National Institute of Allergy and Infectious Diseases, along with collaborators at other institutions, the vaccine produces durable protection, a factor that underlines its promise for clinical translation and pandemic preparedness. So far its safety profile suggests that investigators may be on the brink of a vaccine that, in the not-too-distant future, may help control a Marburg virus outbreak.

The pathogen is extraordinarily virulent, one of the most lethal in the world—an infectious agent so dangerous that it’s on lists of viruses with potential to be exploited in devastating acts of bioterrorism. It causes a severe infection that once was known as Marburg hemorrhagic fever, but now is widely referred to as Marburg virus disease. The pathogen belongs to the Filovirdae family, the same viral family as Ebolavirus.

Writing in the journal Science Translational Medicine, Dr. Ruth Hunegnaw, lead author of a new research paper on a series of studies testing an investigational vaccine in nonhuman primates, underscores the urgent need for measures that can prevent infection and control Marburg virus outbreaks.

“Marburg virus has been identified as a category A bioterrorism agent by the U.S. Centers for Disease Control and Prevention and a Category-A Priority Pathogen by the National Institute of Allergy and Infectious Diseases, needing urgent research and development of countermeasures because of the high public health risk it poses,” Hunegnaw wrote in the journal.

The potential for deadly Marburg virus hotspots and full-blown outbreaks remain a genuine threat, especially on the continent of Africa where rare but lethal outbreaks episodically ignite human infections. As with Ebolavirus, it’s posited that the Marburg infectious agent jumped the species barrier from bats to people and nonhuman primates. While bats live without harm from the pathogen, scientists at the World Health Organization estimate human mortality at 90%.

Between June 28 and September 16 of last year, Ghana’s Ministry of Health was monitoring three confirmed cases of Marburg virus disease. All of the infected, two adults in their twenties and a baby, were from the same household. The 14-month old boy died within three days of hospital admission. His 26-year old father also died. The 24-year-old mother survived; however, health authorities identified a total of 198 contacts for the three family members. All contacts were monitored for 42 days.

Scientists at the Vaccine Research Center of the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland have taken significant steps toward making a vaccine against Marburg virus a reality. Working with collaborators at the National Emerging Infectious Diseases Laboratories of Boston University and the Department of Microbiology and Immunology at the University of Texas Medical Branch in Galveston, the researchers are already analyzing data from a human clinical trial. An investigational vaccine, like the one used in the animal tests, has been administered in a newly completed Phase 1 trial.

Hunegnaw, lead author of the research in nonhuman primates, reports that a single shot of the vaccine generated protective immunity within seven days of vaccination. Additionally—and perhaps more important—the investigational vaccine protected nonhuman primates when they were challenged with exposure to the lethal Marburg virus.

Hunegnaw and her colleagues note that the immunization is called ChAd3-MARV vaccine, an adenovirus-vectored shot that expresses the Marburg virus (MARV) glycoprotein. The harmless adenovirus in the vaccine is of chimpanzee origin, hence the initials “Ch” in the name of the vaccine.

“The recent cases of Marburg virus in West Africa underscore the substantial outbreak potential of this virus,” Hunegnaw reported in Science Translational Medicine. “The potential for cross-border spread, as had occurred during the 2014–2016 Ebola virus outbreak, illustrates the critical need for Marburg virus vaccines.”

Hunegnaw additionally reported that the animals remained protected from the pathogen when exposed to the virus a year after vaccination. The researchers also identified antigen-specific antibodies in the animals’ blood, an important finding as scientists move toward regulatory approval by the U.S. Food and Drug Administration.

Marburg virus was first identified in 1967 when laboratory workers in Marburg and Frankfurt, Germany came down with a virulent hemorrhagic fever. The same infection was diagnosed in a Serbian laboratory worker in Belgrade. Scientists in all three locations were working with infected tissue samples from African green monkeys, Chlorocebus aethiops and were unaware of the exceptionally lethal nature of the virus. A total of 31 people were infected and seven died.

The experimental vaccine, meanwhile, which is being studied in Hunegnaw’s laboratory and elsewhere in the United States, is seen as a major step toward fulfilling multiple goals—a vaccine for regions at risk of Marburg outbreaks and development of a vaccine in the event the virus is used in an act of bioterrorism.

“The demonstration of protection shortly after ChAd3-MARV vaccination and durability of the protection suggests that ChAd3-MARV is suitable for deployment both to protect healthcare workers during an outbreak and in a ring-vaccination scenario,” Hunegnaw concluded.

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The burden of respiratory syncytial virus (RSV)-positive acute respiratory infection (ARI) in older adults was considerable before COVID-19 and is associated with lower quality of life (QOL), according to a study published online Jan. 20 in JAMA Network Open.

Young J. Juhn, M.D., M.P.H., from the Mayo Clinic in Rochester, Minnesota, and colleagues conducted a community-based cohort study that followed 2,325 adults aged 50 years or older for two RSV seasons from 2019 to 2021 to examine the incidence of RSV-positive ARI before and during the COVID-19 pandemic.

The researchers found that the incidence rate of RSV-positive ARI was 48.6 per 1,000 person-years before the pandemic, with an attack rate of 2.50 percent. During the COVID-19 pandemic RSV season, there were no RSV-positive ARI cases identified. During the summer of 2021, the incidence was 10.2 per 1,000 person-years and the attack rate was 0.42 percent.

Participants with RSV-positive ARI reported a significantly lower quality-of-life adjusted mean difference within two to four weeks after RSV-positive ARI compared with matched RSV-negative ARI, based on prepandemic RSV season results. Those with RSV-positive versus RSV-negative ARI had lower quality of life at six to seven and at 12 to 13 months after RSV-positive ARI.

“RSV-positive ARI was associated with significant long-term impacts on health-related QOL beyond the acute infection in adults over 50,” the authors write. “An effective RSV vaccine might be an important measure to mitigate the impact of RSV-positive ARI, especially in older adults.”

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