Zika Breaking News

The Zika virus outbreak in 2015 and 2016 left many children worldwide with devastating brain damage. The New York Times reported on August 16, 2022, how families and researchers find potential cures in the shadow of the COVId-19 pandemic.

About 25% of infected people may develop symptoms, but the illness is usually mild, with symptoms lasting between two and seven days.

However, there is scientific consensus that the Zika virus is a cause of microcephaly and Guillain-Barré syndrome, says the WHO/PAHO.

Microcephaly is a condition where a baby’s head is much smaller than expected.

During pregnancy, a baby’s head grows because the baby’s brain develops, says the U.S. CDC.

Microcephaly can occur because a baby’s brain has not developed properly during pregnancy or has stopped growing after birth, which results in smaller head size.

Furthermore, microcephaly can be an isolated condition, meaning that it can occur with no other significant congenital disabilities or in combination with other major birth defects.

And severe microcephaly is a more serious, extreme form of this condition where a baby’s head is much smaller than expected.

Severe microcephaly can result because a baby’s brain has not developed properly during pregnancy, or the brain started to develop correctly and then was damaged at some point during pregnancy.

As of August 17, 2022, there are no U.S. FDA-approved Zika vaccines.

However, several vaccine candidates are conducting clinical trials listed on this Zika News webpage.

Singapore-based Duke-NUS Medical School and Johnson & Johnson (J&J) jointly launched today a new J&J Satellite Center for Global Health Discovery that will drive new solutions to mitigate the threat posed by flaviviruses such as dengue and Zika. 

The Satellite Center at Duke-NUS is the first of the J&J Centers for Global Health Discovery to open in the Asia-Pacific region.  

Flaviviruses, like dengue and Zika, cause significant illness and death, yet no specific antiviral therapeutics are currently available.

Flaviviruses infect more than 400 million people each year, putting half of the global population at risk.

In particular, Asia bears nearly three-quarters of the global burden.

As Earth evolves, billions of people could be impacted in the coming decades as the animal vectors that carry flaviviruses venture beyond the tropical regions where they have traditionally thrived, spreading the diseases to new areas.  

"The establishment of the Satellite Center at Duke-NUS builds upon our strong track record in flavivirus research and bench-to-bedside innovations and will facilitate antiviral drug discovery for the prevention and treatment of flavivirus-associated diseases that are affecting communities in Southeast Asia and beyond."

"The collaboration is both timely and purposeful in realizing the School's vision of transforming medicine and improving lives," said Professor Patrick Casey, Senior Vice-Dean for Research at Duke-NUS, in a press statement issued on June 21, 2022.

Most recently, the School played a critical role in driving progress to tackle dengue by working with SingHealth’s Investigational Medicine Unit to conduct a Phase 2a clinical trial evaluating Janssen’s antiviral compound for the prevention and treatment of dengue.

As of June 21, 2022, the U.S. FDA had not authorized Zika prevention vaccines. 

Zika vaccine development news is posted at ZikaNews.com/Vaccines.

Note: This news was manually curated for mobile readership.

The World Health Organization (WHO) recently announced the launch of the Global Arbovirus Initiative, an integrated strategic plan to tackle emerging and re-emerging arboviruses with epidemic and pandemic potential.

The most common arboviruses are mosquito-borne illnesses, such as Dengue, Yellow fever, Chikungunya, and Zika.

Zika virus gained worldwide notoriety in 2016 when it was found to cause congenital disabilities such as microencephaly.

Zika remains a health threat in tropical and sub-tropical parts (map) and has been detected in about 89 countries.

"Arboviruses" might not be something most of us are familiar with. Still, they're a deadly threat to almost four billion people, so the UN health agency launched a plan on March 31, 2022, to prevent them from causing a new pandemic.

In a related press statement, Dr. Mike Ryan, head of the WHO's Emergency Programme, explained that the scheme would allow health authorities to tackle the "broad but related threats" posed by Dengue, Yellow fever, Chikungunya, and Zika.

"For each of these diseases, there have been gains in different aspects of surveillance response, research, and development," he said.

"But sustainability is often limited to the scope and duration and scope of disease-specific projects."

"There is an urgent need to re-evaluate the tools at hand and how these can be used across diseases to ensure an efficient response, evidence-based practice, equipped and trained personnel, and engagement of communities."

Furthermore, according to WHO data, Zika outbreaks could continue.

Information on Zika vaccine candidates is posted on this ZikaNew.com/vaccine page.

Note: This news article edited WHO information for clarity and was manually curated for mobile readers.

The Zika virus continues to be a problem in many parts of the world and is often tough to detect. So when considering your next Caribbean travel destination, calculating your ability to protect yourself from mosquito bites is essential.

The Puerto Rico Department of Health Weekly Arboviral Diseases report indicates the Zika virus continues to infect people in 2022. 

The Report published on Feb. 14, 2022, shows (1) new 'probable' Zika cases confirmed in the San Juan, Puerto Rico vicinity.

These Zika cases are in addition to the (101) probable cases reported during 2021, with (10) near the city of San Juan.

The term "probable cases" is defined as infections with a positive serological test (IgM). 

Unfortunately, since Zika virus antibodies can persist for years after infection, serology cannot distinguish between a recent or past infection.

In the U.S., the Centers for Disease Control and Prevention (CDC) reported in 2020, there were (4) locally acquired Zika cases and (47) travel-related.

And none in 2021.

The CDC hosts a world map that displays Zika cases.

As of Feb. 20, 2022, the U.S. FDA has not authorized a Zika vaccine. However, several Zika vaccine candidates are conducting human clinical trials listed on this web page.

According to a new estimate published in U.S. CDC's Morbidity and Mortality Weekly Report (MMWR) on January 21, 2022, about 5% of U.S. infants born to mothers with a confirmed or possible Zika virus infection during pregnancy had a Zika-associated brain or eye defect.

This new study reconfirms a Zika virus infection during pregnancy can cause serious congenital disabilities of the brain and eyes, including intracranial calcifications, cerebral or cortical atrophy, chorioretinal abnormalities, and optic nerve abnormalities.

The frequency of these Zika-associated brain and eye defects, based on data from the U.S. Zika Pregnancy and Infant Registry (USZPIR), has been previously reported in aggregate.

Among 6,799 live-born infants in USZPIR born during December 1, 2015–March 31, 2018, 4.6% had any Zika-associated birth defect.

In a subgroup of pregnancies with a positive nucleic acid amplification test for Zika virus infection, the percentage was 6.1% of live-born infants.

The brain and eye defects most frequently reported included microcephaly, corpus callosum abnormalities, intracranial calcification, abnormal cortical gyral patterns, ventriculomegaly, cerebral or cortical atrophy, chorioretinal abnormalities, and optic nerve abnormalities.

About one-third of infants with any Zika-associated congenital disability had more than one defect reported.

And these brain and eye defects in an infant might prompt suspicion of prenatal Zika virus infection.

Moreover, among 325 pregnancies with laboratory evidence of confirmed or possible Zika virus infection that resulted in a pregnancy loss, 4% of fetuses had any reported Zika-associated congenital disability (C Moore, CDC, unpublished data, 2022).

These findings can help target surveillance efforts to the most common brain and eye defects associated with Zika virus infection during pregnancy should a Zika virus outbreak reemerge, and might signal the reemergence of Zika virus, particularly in geographic regions without ongoing comprehensive Zika virus surveillance.

The findings in this report are subject to at least five limitations. First, these data are based on information abstracted from medical records.

Although CDC provided specific guidance for evaluating all infants born from pregnancies with possible Zika virus exposure during pregnancy, these evaluations might not have been feasible, were not always conducted, or were not found in records.

Corresponding author: Nicole M. Roth, [email protected].

Japan-based Takada Vaccines, Inc. has scheduled a poster presentation for November 19, 2021, during the annual American Society of Tropical Medicine and Hygiene digital meeting.

This presentation, led by Erick Perez-Guzman, Mayuri Sharma, Ralph Braun with Takeda, will discuss how Zika virus-specific antibodies that can be distinguished from antibodies to other flaviviruses (FV), which will improve differential diagnosis and support the development of Zika vaccines in flavivirus-endemic regions''''Zika virus (ZIKV) re-emergence and spread into flavivirus endemic regions have caused serodiagnostic challenges due to antibody cross-reactivity among the FVs.

Currently, there are no viral envelope protein-based assays available to quantitatively measure ZIKV-specific antibody responses in individuals with prior FV exposure.

These presenters describe the development of a ZIKV-specific competitive microsphere-based immunoassay to support ongoing clinical trials of Takeda's purified inactivated ZIKV vaccine (PIZV) candidate.

The assay design allows ZIKV-specific antibodies present in plasma or serum samples to compete with the binding of an anti-ZIKV EDIII monoclonal antibody to a specific epitope on ZIKV virus-like particles coupled to Luminex magnetic microspheres. ZIKV-specific antibody levels in the presence or absence of antibodies to other FVs can then be determined in the samples.

Human and non-human primate (NHP) sample panels exposed to different FVs, including ZIKV, dengue virus (all four serotypes), Yellow Fever virus, Saint Louis Encephalitis virus, West Nile virus, Japanese Encephalitis virus, and Tick-Borne Encephalitis virus, were assessed using this assay.

The assay quantified ZIKV-specific antibodies in all presumptive or confirmed ZIKV or PIZV-immune samples, while all other FV-immune samples were negative in the assay.

Of note, the assay was also able to quantify PIZV-elicited ZIKV-specific antibodies in the presence of cross-reactive antibodies from prior FV vaccination.

In summary, these presenters say our data suggest that the assay can differentiate ZIKV-specific antibodies from antibodies to other FVs elicited by natural infection or vaccination.''

Availability of a ZIKV-specific antibody-based immunoassay will improve differential diagnosis, serosurveillance and support the development and implementation of ZIKV vaccines in FV endemic regions.

Takeda's Zika vaccine candidate (TAK-426; PIZV) is a purified, inactivated, alum-adjuvanted, whole Zika virus vaccine candidate conducting clinical studies.

Though the number of Zika virus infections has decreased since 2018, scientists speculate they may be due to herd immunity in some areas.

However, there is still potential for future outbreaks.

Scientists want to understand how the human immune system recognizes the Zika virus to develop preventive vaccines.

Shannon Esswein, a graduate student, and Pamela Bjorkman, a professor at the California Institute of Technology, presented new insights on how the body’s antibodies attach to the Zika virus. These insights were published in PNAS, February 25, 2021.

To study the antibody response to Zika and other flaviviruses, Esswein and Bjorkman looked at several antibodies from the blood of patients from Mexico and Brazil.

To find antibodies that recognize flaviviruses, they used a piece of the outside of the virus, called the envelope domain III protein.

Previous studies have shown the envelope domain III is an essential target of protective antibodies that fight flavivirus infections.

The researchers studied how those antibodies changed over time as they mature and became better able to stick to the Zika virus and how the antibodies cross-react with other flaviviruses, including the four types of dengue viruses.

They found that the Zika antibodies also tightly stick to and defend against dengue type 1 and weakly stick to West Nile and dengue types 2 and 4.

“The weak cross-reactivity of these antibodies doesn’t seem to defend against those flaviviruses, but also doesn’t induce ADE,” Esswein said, suggesting envelope domain III may be useful to make a safe vaccine.

They also determined structures showing how two antibodies recognize Zika and West Nile envelope domain III.

Together, the team’s experiments show how the body mounts “a potent immune response to Zika virus,” says Esswein.

Their insights into the antibodies involved in this immune response will help inform vaccine design strategy.

As of October 26, 2021, the U.S. FDA had not approved a Zika vaccine.