This Manitoba mom's baby was hospitalized with RSV. Now she's warning of the risk from the virus

rsv infections 2021 :: Article Creator

Research Round-up: Respiratory Syncytial Virus

A colourful cryo-tomogram of a hybrid viral particle.

A hybrid viral particle generated during coinfection by influenza A virus and respiratory syncytial virus.Credit: J. Haney et al. Nature Microbiol. 7, 1879–1890 (2022)

RSV and flu's intimate connection

Respiratory syncytial virus (RSV) and influenza typically circulate contemporaneously, meaning co-infections are common. Clinical studies of such co-infection have so far yielded conflicting results, but some research suggests that it can put people at an increased risk of developing pneumonia.

Researchers at the University of Glasgow, UK, have shown that when RSV and the influenza A virus (IAV) are present in the same cell, they can conjoin to form hybrid viral particles.

The work was conducted solely in cell culture, using cell lines derived from human lungs and lab-adapted virus strains. But if future work shows that such hybrid particles also form in natural co-infections, this research could have significant clinical implications.

Part of Nature Outlook: Respiratory syncytial virus

RSV and IAV were seen to physically conjoin in two ways. But because respiratory viruses spread by filamentous particles budding off from cell membranes, the group focused on the hybrid particles that were located on infected cells' membranes with a filament-based structure.

These particles had necks made of proteins and genomic RNA from RSV, and forked heads consisting of IAV proteins and RNA. And the particles could, indeed, bud off and infect more cells.

Importantly, these hybrid particles were able to use RSV proteins to enter cells that did not have the receptor that would ordinarily allow IAV to enter. IAV usually targets only the upper and middle respiratory tract, but this mechanism could theoretically allow hybridized flu viruses to enter the lower respiratory tract that RSV infects.

Antibodies against RSV were able to neutralize the hybrid particles. But antibodies that usually bind to the flu virus could only weakly target the hybrid particles, suggesting that the particles could escape immunity against flu.

A final experiment showed the two viruses present in the same cultured airway cells taken from volunteers, but the researchers have not shown that this generates hybrid particles — nor that such particles occur naturally.

RSV and flu have long co-circulated, meaning that this phenomenon, if it occurs naturally, is unlikely to be new. Nevertheless, viral hybridization might represent a new frontier in the study of co-infections.

Nature Microbiol. 7, 1879–1890 (2022)

RSV's toll on older people

RSV is mainly thought of as a childhood illness, but two meta-analyses have assessed the threat it poses to older people. The first study confirms that RSV is a significant health burden in older populations and the second concludes that the threat is akin to that of influenza.

Miloje Savic and Yolanda Penders at the pharmaceutical company GSK's campus in Wavre, Belgium, led a review of previous estimates of RSV infections and hospitalization rates — they also looked at the case-fatality rate among those who were hospitalized. The researchers focused on people over the age of 60 in high-income countries because data were limited elsewhere in the world.

On average, 1.6% of people over 60 years old are infected with RSV annually, and 15 in every 10,000 people in this age group are hospitalized. Of those hospitalized, around 7% die. The epidemiologists estimated that in 2019, this corresponded to 5.2 million infections, almost 470,000 hospital admissions and 33,000 in-hospital deaths. Meanwhile, Stefania Maggi at Italy's National Research Council in Padova and her collaborators from across Europe, compared studies that recorded hospitalization and mortality rates due to RSV or influenza infections (again, mostly in high-income countries).

This revealed that RSV and flu account for comparable numbers of hospitalizations and deaths.

Both groups lamented the lack of routine RSV testing in adults and called for better RSV monitoring — especially in low- and middle-income countries where more than 80% of the global population live. Both groups stressed that their findings support the use of preventative measures to protect older people.

Influenza Other Respir. Viruses 17, e13031 (2023); Vaccines 10, 2092 (2022)

Waste not, want not

For RSV interventions to be most effective, public-health specialists need surveillance data on how much of the virus is circulating, and where. But RSV testing is rarely carried out on a routine basis. And even in hospital settings, today's outbreak monitoring remains coarse.

Researchers in the United States provided evidence that wastewater epidemiology might offer a solution.

Drawing on previous studies that indicate that RSV can be shed in the stool of infected individuals, the team developed an assay to quantify viral RNA levels in sewage. Throughout 2021, they collected samples of solid waste from two publicly owned treatment works in the San Francisco Bay Area and measured the amount of viral RNA present. They then plotted these numbers against the best available surveillance data, which were sourced from a state governmental laboratory that records the percentage of clinical samples that test positive for RSV. At both sewage-treatment sites, there was a striking correlation between wastewater RSV content and the confirmed clinical infection rate. Notably, in 2021 RSV cases began to increase in June rather than in October as they normally do, and the wastewater data tracked this.

A main advantage of wastewater testing is that it can indicate community infection rates without requiring active participation from individuals. Such methods are already used to monitor gastrologically associated viruses, such as norovirus, and analogous efforts to track the coronavirus SARS-CoV-2 have quickly matured. This study suggests that wastewater surveillance could provide real-time data about RSV outbreaks to guide public-health responses.

Environ. Sci. Technol. Lett. 9, 173−178 (2022)

The threat of zoonotic reservoirs

The 2020 discovery that pangolins hosted coronaviruses that were genetically similar to those that cause COVID-19 made global headlines and remains a contentious issue in establishing the origins of the pandemic. Fresh research shows that these animals can also be infected with RSV.

Scientists in China examined frozen tissue from 30 pangolins that were seized by customs officers in Guangxi, China, between August 2017 and July 2018. The animals had fallen sick and died while being smuggled from southeast Asia into China. The researchers isolated full-length or near full-length RSV genomes from 12 pangolins (from which, 4 had also carried the coronaviruses). There were three distinct sub-strains of RSV. Each genome was more than 99% identical to an RSV previously identified in human infections.

The authors speculate that the animals were probably infected by their human handlers, with potential pangolin-to-pangolin transmission following. The fact that 12 of the 30 pangolins were infected, the researchers say, might be due to an artificially inflated infection rate because the samples came from a group of sick animals. Whether the pangolins died of RSV or were culled because they were ill is unknown.

The fact that pangolins can host RSV underscores public-health concerns about viral transmission between people and animals, and suggests that further monitoring and analysis of RSV in non-human species is warranted.

Curr. Biol. 32, R307–R308 (2022)

Nose organoids, from swab to dish

Researchers at Baylor College of Medicine in Houston, Texas, have developed a human-nose organoid that they say can be used to research respiratory viruses and to aid the development of therapies.

Organoids are 3D cell cultures grown from stem cells, which divide and differentiate into a mixture of cell types that self-organize to capture, to some degree, the structure and function of in vivo organs. When such models are made from human cells, they can provide pre-clinical models that do not use animal tissues.

Previous efforts to make nasal organoids required taking biopsies from people to harvest stem cells. However, this work, by microbiologist Anubama Rajan and her colleagues, showed that the stem cells needed for creating organoids can be gathered through non-invasive methods such as a nasal wash or swab.

CDC Makes Another RSV Shot Approval: Here's Who Needs A COVID, Flu And RSV Shot

The US Centers for Disease Control and Prevention last week recommended an RSV vaccine (Abrysvo) for people in their third trimester of pregnancy in order to protect their newborns once they're born.

RSV (respiratory syncytial virus) is a common respiratory virus that's mild in most people but can cause severe illness in certain groups, particularly babies and older adults. Prior to the CDC's recommendation for pregnant people to get an RSV vaccine, it was approved and has been available for older adults in their 60s and older, giving the most vulnerable populations tools for protection for the first time this year.

COVID-19 vaccines just recently became available, and with the addition of the annual flu vaccine, most people are recommended at least two shots this fall and winter season. And if you haven't gotten any shots yet, don't stress: October is great time to get optimally protected ahead of cold-weather months, when more people are spending time indoors and respiratory viruses thrive.

Here's what to know about the COVID, RSV and flu vaccines this year and who should get each one.

Read more: Take 2 Minutes and Order 4 Free COVID Tests

Adults in their 60s and up may get three vaccines

If you're in your 60s or older, you have a higher risk of getting really sick from flu, COVID-19 and RSV. Here's what the CDC says about all three recommendations for your age group.

COVID vaccine: Strong yes

You can get a new formula and single shot of Pfizer's or Moderna's COVID-19 vaccine right now, as long as it's been two months since your last dose. To find a shot near you, enter your ZIP code in Vaccines.Gov. Your insurance (private or Medicare) should cover the entire cost of the shot, but you can check with your provider to make sure you're going to a place in-network.

If you don't have health insurance, the COVID shot will still be free if you book your appointment at a pharmacy participating in the Bridge Access Program, which includes many CVS and Walgreens locations. (Click the "Bridge Access Program" box when you make your appointment online.)

Flu vaccine: Strong yes

Older adults have a higher risk of severe illness from the flu. In recent years, it's been estimated that between 70% and 85% of deaths from the flu were in people age 65 or older. Of the different flu vaccines available each year, the CDC recommends older adults get a higher-dose flu vaccine, if one's available near you and it's convenient to get.

RSV vaccine: Up to you and your doctor

There are two RSV vaccines available for adults 60 and older. When the CDC recommended the RSV vaccine for this group, it did so with something called "shared clinical decision-making." This means that while the risk of RSV isn't identical across the age group (people with chronic health conditions like lung or heart disease and people who live in a nursing home or other care facility have a high risk, for example), all older adults should have the option to receive the vaccine.

If you have questions on whether you should get one, talk with your doctor or pharmacist. According to the CDC, RSV causes approximately 60,000 to 160,000 hospitalizations and 6,000 to 10,000 deaths every year among older adults.

Pregnant? You may also get three shots

Health officials have always stressed the importance of getting vaccinated against the flu during pregnancy because of the potential for complications the virus can cause. The same is true for COVID-19 -- the vaccines are recommended by medical organizations that treat pregnant people and their newborns, including the American College of Obstetricians and Gynecologists.

The RSV vaccine is recommended for use in pregnancy during weeks 32 through 36 of pregnancy. When it's given during pregnancy, the antibodies will offer babies some protection in the months after they're born. According to the CDC, the RSV vaccine has been shown to reduce the risk of RSV hospitalization for babies by 57% in the first six months after birth.

The vaccine isn't the only RSV news for people who are pregnant and their babies. Also this year, the FDA approved and the CDC recommended a new monoclonal antibody treatment for very young children that can reduce the risk of hospitalizations from RSV by up to 80%, called nirsevimab. It can be given to young children like a shot to all babies in their first RSV season, and some children 8 to 19 months in their second RSV season.

The CDC noted that most babies will only need one shot -- either the maternal vaccine through their parent when pregnant or the monoclonal antibody.

Everyone else

Everyone age 6 months and older, with rare exceptions, should get an annual flu vaccine, according to the CDC. While there are a few different flu shots available, if you're younger than age 65, it shouldn't matter which one you get (save, of course, people with allergies). However, certain people (including people who are pregnant, people with weakened immune systems and other health conditions) shouldn't get the nasal spray vaccine.

To find a flu vaccine, you can use Vaccines.Gov to search for appointments and pharmacies near you.

Similarly, everyone age 6 months and older can get an updated COVID-19 shot, as long as it's been at least two months since your last dose. If you recently had COVID-19, the CDC says you can consider waiting three months since your infection to the COVID shot. As a post from the Johns Hopkins Bloomberg School of Public Health points out, there is research that suggests waiting a few months longer (up to six months) post-infection makes sense for some people as a way to stretch out their immunity, but it would depend on the individual, their individual risk factors and more. If you have questions about the right timing for you, talk to your doctor.

It's also safe to get the flu vaccine and the COVID vaccine at the same time.

Read on for information about free COVID tests and treatment, as well as how to use the government program for free COVID vaccines for adults without health insurance.

When Should You Get Your Fall Covid-19, Flu, And RSV Vaccines? The Science Of Timing It Just Right

Fall is more than the start of flu season. Now, it's also the time to get vaccinated against up to three viruses: flu, Covid-19, and respiratory syncytial virus (RSV). But is there an exact science behind vaccine timing? In short, ideally before November 1.

It's safe to get boosted for flu and Covid-19 at the same time, according to public health expert and vice president of science, medicine, and public health for the American Medical Association (AMA) Andrea Garcia. The main advantage there isn't necessarily linked to a more fortified immune system, but rather a trip saved. Pairing flu and Covid-19 vaccines saves you an additional appointment, and delaying one could mean putting it off entirely.

Garcia also suggests the best months for vaccination. "In general, September and October are really good times to get the flu vaccine," Garcia said on the podcast AMA Update. The Centers for Disease Control agree that September and October are prime vaccine months because they immediately precede peak flu circulation, which is historically between December and February. This also goes for RSV. The RSV vaccine, which was approved by the Food and Drug Administration for adults over 60 this past May, is now available in major pharmacies. For those who need all three, it's safe and convenient to get them all at once.

Elderly adults and other people vulnerable to these viruses should also wait until this window to get vaccinated so their immunity will be strongest when infections are most rampant, according to the CDC. Healthy adults, however, have flexible timing because neither virus poses as large a health risk as it does to the elderly and more vulnerable adults.

The priority, however, is to get vaccinated before sickness starts spreading. Jennifer Nuzzo, epidemiology professor and director of the Pandemic Center at the Brown University School of Public Health, previously told Inverse that the best time to get inoculated is, essentially, before you're infected. Of course, when flu, Covid-19, and RSV cases rise in later autumn, you're much more likely to contract at least one of them.

"The goal is generally to get vaccinated before the virus is spreading in your community," Garcia said.

If you have or recently had Covid-19, then you'll want to hold off on the vaccine. Once you're symptom-free and testing negative, the infection acts as a natural boost of immunity that can last about three months, Nuzzo said; there's no point in also getting vaccinated if you're naturally immunized. When you're through with Covid-19, get your flu (and possibly RSV) vaccine — Covid-19 immunity does nothing against influenza.