Tag Archives: Vaccinations

Microbiology

The pandemic virus SARS-CoV-2 continues to cause infections as it mutates into new variants. While the vaccines that …

Leave a comment

The pandemic virus SARS-CoV-2 continues to cause infections as it mutates into new variants. While the vaccines that are available have been able to significantly reduce the likelihood that vaccinated people will be hospitalized or die from the virus, they have not been exceptionally good at preventing infection. The mRNA vaccines are also based on the spike protein, which has kept evolving as new variants have emerged, and protection is waning.

Colorized scanning electron micrograph of a cell (purple) infected with the Omicron strain of SARS-CoV-2 virus particles (green), isolated from a patient sample. Image captured at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. Credit: NIAID

Researchers have been trying to develop a great vaccine for SARS-CoV-2 since the COVID-19 pandemic began, but traditional vaccines can take years to perfect, produce, and test. We were lucky to have access to mRNA technology that brought us vaccines quickly, but there is a lot of room for improvement.

New research reported in Science Translational Medicine has described a different approach to a SARS-CoV-2 vaccine that has taken inspiration from evolution of the virus. In this study, the investigators assessed he sequences of 11,650,487 SARS-CoV-2 samples. This revealed that the spike protein of the virus, which is used by the pathogen to latch onto and infect cells, has not experienced a random evolutionary trajectory. Instead, the virus has followed paths of either high infectivity with low immune resistance or low infectivity with high immune resistance.

The infectivity and immune resistance of SARS-CoV-2 variants tend to be incompatible, the researchers found, with the exception of the Beta and Kappa variants. Omicron exhibited the highest degree of immune resistance when it was tested in cell lines, and demonstrated high infectivity in one type of cell.

The researchers used this data to design a vaccine antigen called Span, which is aimed at multiple targets on the virus. The Span protein carries sequences that are consistently found in many viral variants throughout the evolution of the virus, so the vaccine should provide protection against many existing and emerging variants of SARS-CoV-2.

When tested in an animal model, the Span vaccine triggered the production of antibodies that could neutralize different variants of the SARS-CoV-2 virus, and was totally effective against mortality caused by Omicron. This study has highlighted how different vaccine designs can help keep people protected as the SARS-CoV-2 virus continues to evolve and cause new infections. This vaccine stil has to be tested in people, however.

Other teams of researchers are also working to develop different kinds of SARS-CoV-2 vaccines.

Source: Science Translational Medicine


Carmen Leitch

Microbiology

While it has gotten competition from SARS-CoV-2, the virus that causes COVID-19, measles is also a virus that …

Leave a comment

While it has gotten competition from SARS-CoV-2, the virus that causes COVID-19, measles is also a virus that is known as one of the most infectious diseases there is. While it causes mild symptoms like watery eyes, cough, fever, and a rash in many cases, it can lead to very serious complications and death in some people. About 90 percent of people who are not vaccinated will contract the illness when they are exposed, and roughly one in five will have to be hospitalized for treatment. Children are particularly vulnerable.

A 3D graphic representation of a measles virus particle / Credit: CDC/ Allison M. Maiuri, MPH, CHES / Illustrator: Alissa Eckert

From 2017 to 2019, India began a campaign to eradicate measles. To achieve herd immunity, which stops infectious illnesses from spreading, 95 percent of children need to receive two doses of the measles vaccine (or MMR for measles, mumps and reubella). The effort was going well until the pandemic, when vaccination rates plummeted. From 2019 to 2021, only about 56 percent of Indian kids got both MMR doses. Now, measles is spreading in India and officials are trying to control it; it already caused 12,773 confirmed cases in November alone, according to the World Health Organization (WHO).

In the US, parents are advised to get the first MMR dose for children between 12 and 15 months old, and then another when the kids are between 4 and 6 years old.

Vaccine hesitancy, in which people start opting themselves or their children out of vaccine doses, is also becoming more widespread. In the United States, some polls have suggested that as many as 40 percent of people now question the value of vaccines. People and their kids are now starting to pay a price for their doubts. Measles is also spreading in Ohio, and the majority of cases there have affected unvaccinated kids.

Most of those infected with measles in Ohio are unvaccinated and under age 5. Several have an unclear vaccination status or have only gotten one of two doses. The first four cases involved children who had connections to the same child-care facility in Franklin County, Ohio. So far, 32 children have been hospitalized.

Other diseases are surging too. Cholera, a disease caused by a bacterium called Vibrio cholerae, is affecting several regions right now. There have been seven cholera pandemics during the past two centuries, according to WHO. The seventh was at its worst from 1961 to 1974, but it is considered to be still ongoing. Global incidence has decreased in many areas. However, the true burden of cholera is not known because most cases are not recorded. At least 95,000 people are thought to die of cholera, an acute diarrheal infection, every year.

Countries with fragile infrastructure, particularly in healthcare, are especially impacted by cholera. Humanitarian crises, and extreme weather events like flooding that are due in part to climate change, are also to blame for exacerbating the problem.

In 2022, severe flooding affected Pakistan and Nigeria, tropical cyclones hit Malawi and Mozambique, and drought occurred in the Horn of Africa; all of these areas are now reporting cholera outbreaks. Political instability and violence are also occurring in Afghanistan, Cameroon, the Democratic Republic of Congo, Haiti, and other countries where cholera outbreaks are ongoing.

The impacts of COVID-19 are also making it harder for authorities to respond effectively to public health threats.

Sources: Medical Xpress, Nature, World Health Organization (WHO)


Carmen Leitch

Microbiology

Indian pediatrician Soumya Swaminathan is departing her job at the World Health Organization (WHP) as chief scientist, and …

Leave a comment

Indian pediatrician Soumya Swaminathan is departing her job at the World Health Organization (WHP) as chief scientist, and will return to work in India. She was the first to hold the position, which was created by WHO Director-General Tedros Adhanom Ghebreyesus to monitor scientific developments related to the COVID-19 pandemic in 2019, after joining WHO in 2017. Kai Kupferschmidt of Science magazine interviewed Swaminathan about her experience.

Transmission electron micrograph of SARS-CoV-2 Omicron virus particles (gold) replicating within the cytoplasm of an infected CCL-81 cell (teal). Image captured at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. Credit: NIAID

In the interview, she was asked directly about WHO’s failure to quickly stress that SARS-CoV-2 is an airborne virus, which in hindsight, seems to have been a massive error. A multitude of studies have shown that SARS-CoV-2 can indeed be transmitted through the air, something that many people may still not know.

Swaminathan replied that WHO did stress that ventilation and masking were important steps that could be taken to prevent the spread of the virus. But also that there was evidence that revealed the airborne nature of the virus. She agreed that WHO was “not forcefully saying: ‘This is an airborne virus,'” and she added “I regret that we didn’t do this much, much earlier.”

When asked why that happened, Swaminathan explained that her job was brand new and even she was having difficulty knowing what her duties actually were. She was thrust into a spokesperson role, when that was not originally intended to be part of her job. She started out by promoting standards and normalization of healthcare practices, for example. But the pandemic redirected her efforts.

The pandemic response was also stymied by existing paradigms for responding to pathogens, which have been centered on influenza, a very different virus from SARS-CoV-2.

Swaminathan has accomplished some notable goals, though. She noted that even without any help from Moderna or BioNTech-Pfizer, the WHO mRNA vaccine technology hub was opened. Located in Cape Town, South Africa, the facility is aiming to provide mRNA vaccines to Africa. Scientists there have been able to create a vaccine that is now undergoing clinical testing. There have been hurdles, but there are also promising results.

WHO has some new collaborators as well, like the International Science Council that connects the organization to 130 global science academies. The WHO Science Council, which is chaired by Nobel laureate Harold Varmus, was also created last year.

Source: Science


Carmen Leitch

Microbiology

Lyme disease is caused by a bacterium called Borrelia burgdorferi, which is transmitted by tick bites. The incidence …

Leave a comment

Lyme disease is caused by a bacterium called Borrelia burgdorferi, which is transmitted by tick bites. The incidence of Lyme disease has been increasing steadily, in part because diagnosis is improving, but also because the range of ticks that spread the disease is expanding. There is still a lot we don’t know about Lyme disease, including how to treat it. But diagnosis may get easier soon, now that researchers have identified 35 genes that are more active in people with a long-term form of the disease; the genes could be useful in Lyme disease diagnostics. These genes may also aid in the development of therapeutics for Lyme. The findings have been outlined in Cell Reports Medicine.

The blacklegged ticks, Ixodes pacificus (seen here), and I. scapularis, transmit Borrelia burgdorferi, the pathogen that causes Lyme disease. / Credit: CDC/ James Gathany; William L. Nicholson, Ph.D. / Photo Credit: James Gathany

While about 30,000 people are diagnosed with Lyme disease in the United States every year, the true number could be as high as 476,000, according to the Centers for Disease Control and Prevention. People who are diagnosed can be treated with antibiotics, but about 20 percent of patients will go on to develop long-term complications that can affect the neurological system, cause arthritis, or heart problems.

There is a major need for better tests for Lyme disease, and this work is the first to look for transcriptional changes associated with long-term cases.

“We wanted to understand whether there is a specific immune response that can be detected in the blood of patients with long-term Lyme disease to develop better diagnostics for this debilitating disease,” said senior study author Avi Ma’ayan, Ph.D., a Professor and Director of the Mount Sinai Center for Bioinformatics at Icahn Mount Sinai.

In this study, the researchers sequenced the RNA in blood samples from 152 patients with post-treatment Lyme disease symptoms, 72 patient with acute Lyme disease, and 44 uninfected individuals. That RNA can provide a snapshot of how active the patient’s genes were (in the blood) at the time the blood was drawn. The researchers were particularly interested in genes related to the immune response.

This revealed that there was a unique inflammatory pattern in the post-treatment Lyme disease patients compared to those with acute Lyme disease. Within that group of inflammatory genes, there were some that were expressed in a way that is different from other patterns caused by infections with other pathogens. Machine learning was used to create a set of mRNA biomarkers that can differentiate between healthy people, those with post-treatment Lyme disease, or acute Lyme disease. This highly expressed subset of genes has been found before, and could be used to diagnose Lyme disease, as well as which stage it is.

“A diagnostic for Lyme disease may not be a panacea but could represent meaningful progress toward a more reliable diagnosis and, as a result, potentially better management of this disease,” said Dr. Ma’ayan.

The investigators want to repeat the study with other samples, develop a diagnostic tool, and test it with patient samples. They are also interested in using machine learning to find ways to diagnose other challenging disorders.

A vaccine for Lyme disease is also being tested, as outlined in the video.

Sources: The Mount Sinai Hospital, Cell Reports Medicine


Carmen Leitch