Immunization and Respiratory Diseases Bulletin

Updates on respiratory illness and vaccine-preventable diseases.

April 5, 2024, 2:50 PM EDT

What CDC knows

H5N1 bird flu has been spreading in wild birds and causing outbreaks in poultry with infections in a growing number of other animals worldwide. It is now causing a multi-state veterinary outbreak in the U.S. in a new animal: dairy cows. In addition, there has been one confirmed human infection in a person who works with cows. CDC has been tracking and evaluating H5N1 bird flu for decades and is actively engaged with these recent developments because H5N1 bird flu has the potential to infect more humans and become a more widespread problem. Preliminary epidemiologic and laboratory data are reassuring, leading CDC to conclude that the current H5N1 risk to the general public remains low.

What CDC is doing

CDC is working with USDA, FDA, and state health departments to monitor people who may have been exposed to H5N1 bird flu infected animals and test people who develop symptoms. CDC has updated and expanded its recommendations for the prevention and control of H5N1 to include measures for people that are exposed to other animals, including cows, that may be infected with this virus. The CDC lab has sequenced and analyzed the virus from the person who tested positive for H5N1, published a summary of their findings, and provided the full sequence of this virus to public databases. The virus from the Texas human case is very similar compared to those from poultry and impacted cattle, with only a few minor changes. There is no evidence of genetic adaptation that would make the virus more likely to spread from person-to-person. Additionally, the virus is picked up by CDC tests, susceptible to currently available flu antiviral medications, and at this time, there is no sign of person-to-person spread of this virus. CDC will continue to remain engaged with this situation.

Keep reading: Update: Human Infection with Highly Pathogenic Avian Influenza A(H5N1) Virus in Texas

April 4, 2024, 4:45 PM EDT

What CDC knows

Worldwide, measles cases and outbreaks are on the rise, and U.S. measles-mumps-rubella (MMR) vaccination coverage has been decreasing since the start of the COVID-19 pandemic. For some communities, it has fallen below the 95 percent coverage level needed to prevent measles outbreaks. Some communities in the U.S. have even lower MMR vaccination coverage, putting them at high risk for a measles outbreak.

What CDC is doing

In addition to providing clinical guidance to healthcare providers and technical and communications support and vaccines to health departments, CDC is monitoring the measles situation globally and creating models of how measles could spread in the U.S. These models can be used to help federal, state, local, tribal and territorial health departments prepare for possible measles cases, better understand how to identify communities at highest risk, and manage healthcare resources.

Keep reading: Measles Outbreak Risk in the U.S.

March 22, 2024, 4:30 PM EDT

What CDC knows

Improving ventilation, whether natural or mechanical (air flow, filtration, and air treatment), reduces the number of small respiratory virus particles in indoor air, helping lower the risk of transmission. Ventilation is one of many tools available to help protect people from respiratory viruses.

What CDC is doing

CDC is providing actionable steps that people can take to reduce the number of small respiratory virus particles that circulate in indoor air. On March 1, 2024, CDC released updated guidance for respiratory viruses, which recommended taking  steps for cleaner air, along with staying up to date on vaccines for respiratory illnesses such as COVID-19 and flu, as core prevention strategies to lower risk. Some of these recommended actions to improve ventilation may require systems-level changes, but individuals can still take steps to reduce exposure to virus particles in buildings, especially in their homes.

Keep reading: Ventilation Can Reduce Exposure to Respiratory Viruses in Indoor Spaces

March 8, 2024, 4:15 PM EDT

What CDC knows

Measles is an extremely contagious virus that can make people very sick. A measles infection can cause serious problems, like pneumonia, encephalitis (infection and swelling of the brain), or even death. The number of measles cases and outbreaks are rising globally, increasingly in countries often visited by U.S. travelers. Recently, measles outbreaks have been reported in multiple U.S. states, including in daycares and schools.

What CDC is doing

CDC works with state and local health departments to prevent the spread of measles. CDC recommends that everyone get the measles-mumps-rubella (MMR) vaccine. This vaccine is safe and works well to protect against these diseases. It is part of the routine immunization schedule for all children and adults that doctors follow. CDC also has special guidance for people travelling internationally. If measles cases are detected in a community, it is important for public health to take action to stop it from spreading. There’s a well-known playbook to do just that. To prevent transmitting measles to others, people who are exposed to measles but haven’t been vaccinated are recommended to stay home and away from settings where unvaccinated people may be exposed, like schools and daycares.  This helps protect vulnerable people who are unable to get vaccinated from getting infected..

Keep reading: Measles in the United States — March 2024

March 1, 2024, 3:40 PM EDT

What CDC knows

As the 2023-2024 fall and winter virus season ends, it’s clear that the situation surrounding COVID-19 has changed.  It is still an important health threat, but it is no longer the emergency that it once was, and its health impacts increasingly resemble those of other respiratory viral illnesses, including flu and RSV.

What CDC is doing

CDC released updated Respiratory Virus Guidance in response to the decreasing risk that COVID-19 poses to the population. This updated Guidance includes strategies to protect people at highest risk of getting seriously ill and provides actionable recommendations for people with common viral respiratory illnesses, including COVID-19, flu, and RSV.

Keep reading: CDC’s Updated Respiratory Virus Guidance: What to do When You Are Sick

February 23, 2024, 6:15 PM EDT

What CDC knows

The impact of SARS-CoV-2, the virus that causes COVID-19, has changed dramatically since 2020. Although COVID-19 remains common, when compared to 2020, individual infections are less likely to result in severe illness for most people in the United States. COVID-19 poses the highest risk for older adults, infants, and people with pre-existing medical conditions, and there are multiple ways people and communities can help reduce their risk of infection.

What CDC is doing

CDC continues to partner with state and local health authorities to collect and share data on COVID-19 community spread, hospitalizations, deaths, and Long COVID.  Additionally, CDC continues to evaluate the effectiveness of prevention and treatment strategies for the virus in order to provide the public the best evidence-based recommendations for reducing their risk from COVID-19.

Keep reading: The Changing Threat of COVID-19

February 16, 2024, 5:20 PM EDT

What CDC knows

Hospital admissions for COVID-19, flu, and RSV have been declining in most parts of the country for the past few weeks. Some key indicators, however, show that flu activity is rising again in some parts of the United States. CDC expects many more weeks of respiratory disease circulation and possibly a second wave of flu activity.

What CDC is doing

CDC continues to track indicators of respiratory virus activity. You can protect yourself by staying up to date on your vaccines and with timely use of testing, treatment, and other measures.

Keep reading: 2023-2024 Respiratory Virus Season Is Likely Past Peak but Far from Over

February 9, 2024, 4:20 PM EDT

What CDC knows

BA.2.87.1, a new variant of SARS-CoV-2, the virus that causes COVID-19, was identified in South Africa by the National Institute for Communicable Diseases. CDC is closely tracking this variant because of the large number of mutations when compared to previous variants. At this time, BA.2.87.1 has not been identified in clinical specimens outside South Africa. Because this is a newly emerging variant, there is not as much additional data about its potential impact. So far, the public health risk for this new variant appears low.

What CDC is doing

CDC continues to track the appearance and spread of new variants around the world through genomic surveillance. CDC is working closely with partners in South Africa to gather the latest information on BA.2.87.1. CDC and its partners are continually assessing potential impacts to vaccines, tests, and treatments.

Keep reading: CDC Tracks New SARS-CoV-2 Variant, BA.2.87.1

February 1, 2024, 1:05 PM EDT

What CDC knows

New CDC data show that the updated COVID-19 vaccines were effective against COVID-19 during September 2023 – January 2024, including against the different circulating virus variants such as JN.1 and XBB. Getting vaccinated now can help lower the risk of becoming infected with or dying from COVID-19. CDC recommends everyone 6 months or older receive the updated 2023-2024 COVID-19 vaccine.

What CDC is doing

CDC analyzes circulating variants of the virus that causes COVID-19 and assesses how well COVID-19 vaccines protect people. We do this by looking at vaccine effectiveness against infection with symptoms or against severe disease, including hospitalization and death. Through CDC’s Bridge Access Program, COVID-19 vaccines are available at no cost to people who are uninsured or underinsured.

Keep reading: COVID-19 Vaccine Effectiveness

January 22, 2024, 5:15 PM EDT

What CDC knows

Respiratory disease activity in the United States remains high despite recent declines in some indicators. Influenza (flu) is currently the respiratory virus causing the most emergency department visits. The most common influenza viruses this season are type A(H1N1) and type B viruses. JN.1 continues to be the most widely circulating variant of SARS-CoV-2, the virus that causes COVID-19, in the United States and around the world.

What CDC is doing

CDC is studying the impacts of COVID-19 and flu illness this season, encouraging vaccination and prompt antiviral treatment for COVID-19 and flu, and studying vaccine effectiveness. CDC is still learning more about the JN.1 variant and tracking its spread.

Keep reading: Influenza Viruses Spreading This Season and Update on JN.1 Variant

January 12, 2024, 3:45 PM EDT

What CDC knows

Respiratory disease activity remains elevated, in line with projections, with hospital admissions for COVID-19 and flu still high. This could strain hospitals in some areas, making it harder for some patients to get medical care.

What CDC is doing

CDC is using multiple data systems to closely track signs of stress on the healthcare system as hospital admissions are expected to remain elevated. CDC shares these data with partners in federal, state, and local governments to inform healthcare planning and response.

Keep reading: CDC Tracks Hospital Capacity as Respiratory Diseases Continue to Spread

January 5, 2024, 5:45 PM EDT

What CDC knows

The prevalence of the JN.1 variant continues to increase. JN.1 is now the most widely circulating variant of SARS-CoV-2, the virus that causes COVID-19, in the United States and around the world. Based on current data, available vaccines, tests, and treatments work against JN.1.

What CDC is doing

CDC, in collaboration with state and local public health departments, continues to track SARS-CoV-2 variants present in the United States, including JN.1. There is no evidence at this time that JN.1 causes more severe disease than other circulating variants.

Keep reading: COVID-19 Activity Increases as Prevalence of JN.1 Variant Continues to Rise

December 22, 2023, 4:15 PM EDT

What CDC knows

CDC is tracking JN.1, one of many variants of SARS-CoV-2, the virus that causes COVID-19. As of December 23, 2023, JN.1 is projected to account for approximately 39-50% of circulating variants in the United States. The proportion of JN.1 continues to increase more rapidly than other variants. Based on laboratory data, existing vaccines, tests, and treatments work against JN.1. The JN.1 variant doesn’t change how we can protect ourselves and our communities. At this time, the spread of JN.1 does not appear to pose additional risks to public health beyond that of other recent variants. CDC is closely monitoring COVID-19 and will communicate if the situation changes.

What CDC is doing

CDC continues to track JN.1 and other emerging variants, in close collaboration with partners around the world. CDC is also closely tracking COVID-19 activity in the United States through multiple indicators.

Keep reading: CDC Continues to Track the Growth of JN.1

December 21, 2023, 5:00 PM EDT

What CDC knows

Antivirals are an important tool for treating people with COVID-19, yet often are underused. COVID-19 antivirals help reduce hospitalizations and deaths among people at higher risk, especially people 65 years and older and those with certain underlying conditions. COVID-19 hospitalizations are currently on the rise, especially among those over 65 years of age. COVID-19 antivirals need to be prescribed more often to people who are at risk for severe illness to reduce hospitalizations and save lives.

What CDC is doing

CDC is working with healthcare providers and the public to improve understanding of the benefits of antivirals. CDC is also conducting research to better explain uptake and effectiveness of these drugs, as well as supporting treatment access programs, developing clinical resources, and communicating with the public and public health partners. CDC is committed to the equitable access and uptake of antivirals among people who are at higher risk for severe illness.

Keep reading: If You Get Sick with COVID-19, Antiviral Treatments Can Protect You Against Severe Illness

December 14, 2023, 5:00 PM EDT

What CDC knows

Respiratory illness activity is rapidly increasing across the United States, yet vaccination rates for COVID-19, influenza, and respiratory syncytial virus (RSV) remain low. Millions of people may get sick in the next month or two, and low vaccination rates means more people will get more severe disease. Getting vaccinated now can help prevent hospitalizations and save lives.

What CDC is doing

CDC is reaching out to healthcare providers and clinicians to encourage them to recommend all patients receive all respiratory immunizations they are eligible for. On December 14, CDC issued a Health Alert Network (HAN) advisory to raise awareness about respiratory illness activity and urge action. To increase vaccination coverage, COVID-19 vaccines are available at no cost to people who are uninsured or underinsured through the Bridge Access Program.

Keep reading: Peak Season for Respiratory Diseases Is Near: There Is Still Time to Get Vaccinated

December 8, 2023, 11:45 AM EDT

What CDC knows

JN.1, a variant of the virus that causes COVID-19, is a closely related offshoot of the variant BA.2.86 that CDC has been tracking since August. JN.1 is currently projected to comprise 15-29% of circulating variants and continues to grow quickly compared with other variants. Its continued growth suggests that it is either more transmissible or better at evading our immune systems. At this time, there is no evidence that JN.1 presents an increased risk to public health relative to other currently circulating variants, and CDC is closely monitoring COVID-19 activity and JN.1 spread. The increase of this variant does not alter CDC’s COVID-19 recommendations, meaning that vaccines, tests, and treatments continue to work well against JN.1.

What CDC is doing

CDC will continue to track JN.1 and other variants, working closely with partners around the world, to provide the latest information. It’s a great time to get an updated COVID-19 vaccine if you haven’t already had one this fall, since infections are likely to increase in the coming weeks, as they tend to do this time of year regardless of variant.

Keep reading:

CDC is tracking a SARS-CoV-2 variant called JN.1 and working to better understand its potential impact on public health. This update follows CDC’s most recent variant update on November 27, 2023.

Find more information about virus trends in your area and tips to help you stay healthy during the holidays.

December 6, 2023, 4:30 PM EDT

What CDC knows
Testing wastewater (sewage) provides timely, actionable data to understand the spread of the virus that causes COVID-19 within communities. This makes wastewater monitoring an important tool to detect an increase of COVID-19 in the community. Wastewater data can be used alongside other data such as hospitalizations, visits to the doctor, or testing sick people to give a more complete picture of the spread of the virus that causes COVID-19 in your community.

What CDC is doing
CDC launched a new data dashboard that makes it easier to interpret and use wastewater data from CDC’s National Wastewater Surveillance System (NWSS). It’s now possible to see national, regional, and state trends of COVID-19 spread based on virus levels detected in wastewater in all 50 states, U.S. territories, and select tribal nations. This allows people to monitor wastewater data in their area and see how that compares to the rest of the United States.

Keep reading: Using Wastewater Data

December 1, 2023, 8:30 PM EDT

What CDC knows
CDC has been monitoring increases in respiratory illness recently reported around the world.

What CDC is doing
CDC uses multiple data sources to monitor for increases in respiratory illness. CDC is also collaborating with state and local public health departments to closely monitor pediatric pneumonia cases in the United States.

Keep reading: Pediatric Pneumonia Update

November 27, 2023, 1:15 PM EDT

What CDC knows
BA.2.86, a variant of the virus that causes COVID-19 that CDC has been tracking since August, is currently projected to comprise 5-15% of circulating variants. At this time, the expected public health risk of this variant, including its offshoot JN.1, is low. The increase of this variant does not affect CDC’s COVID-19 recommendations.

What CDC is doing
CDC continues to track new variants, working closely with partners around the world, to provide the latest information. It’s a great time to get an updated COVID-19 vaccine if you haven’t already had one this fall, since infections are likely to increase in the coming months, as they tend to do this time of year.

Keep reading: Update on SARS-CoV-2 Variant BA.2.86 Being Tracked by CDC

November 22, 2023, 9:00 AM EDT

What CDC knows
On November 16, CDC posted the first detailed estimates of who has gotten updated COVID-19 vaccines this fall. The data show that COVID-19 vaccine uptake is lower than we’d like to see and there are disparities in uptake by race and ethnicity. This means a lot of people are missing out on the benefits of vaccination. There are many social, geographic, political, economic, and environmental factors that create challenges to vaccination access and acceptance, and that often affect racial and ethnic minority groups.

What CDC is doing
Respiratory viruses don’t affect everyone equally. Certain groups of people are more likely to get very sick or die from COVID-19, and one reason is that there are big disparities in vaccination uptake. CDC is committed to vaccine equity so that everyone has fair and just access to vaccination. CDC continues to work to address vaccine inequities and their underlying drivers.

Keep reading: COVID-19 Vaccine Uptake and CDC’s Commitment to Vaccine Equity

November 21, 2023, 3:30 PM EDT

What CDC knows
Monitoring vaccine safety is an important responsibility shared by the CDC and the FDA.

What CDC is doing
The Vaccine Adverse Event Reporting System (VAERS) is an early-warning monitoring system for vaccine safety. It allows patients, pharmaceutical companies, medical personnel and other users to report concerns about medical events that occurred after someone received a vaccination. What VAERS doesn’t do, though, is tell us whether a vaccine caused a medical issue. That requires investigation. VAERS has a proven track record of successfully helping to identify safety issues.

Keep reading: VAERS: A Critical Part of the National Vaccine Safety System

November 9, 2023, 2:00 PM EDT

What CDC knows
Viruses tend to spread more commonly during fall and winter, especially the respiratory viruses that cause flu, COVID-19, and RSV illness. For many, gathering with loved ones to celebrate the holidays during this season is an important tradition. Fortunately, there are steps you can take to help you and your loved ones stay healthy this holiday season.

What CDC is doing
CDC continually monitors respiratory viruses, including what viruses are spreading and where, who they are affecting, and how well vaccines and medications are working against those viruses.

Keep reading: Take Steps to Help You Stay Healthy During the Holidays

November 2, 2023, 4:00 PM EDT

What CDC knows
Some people may prefer to get their recommended flu, COVID-19, and RSV vaccines at the same time. You should consider getting these vaccines at the same time if making multiple visits to get additional vaccines would be difficult for you.

What CDC is doing
CDC has reviewed the available scientific evidence and concluded that people may get flu, COVID-19, and RSV vaccines at the same visit.

Keep reading: What to Know About Getting Flu, COVID-19, and RSV Vaccines at the Same Time

October 30, 2023, 3:00 PM EDT

What CDC knows
CDC’s Center for Forecasting and Outbreak Analytics continues to anticipate that the upcoming fall and winter respiratory disease season will likely result in a similar number of hospitalizations as last season.

What CDC is doing
CDC will continue to monitor respiratory virus activity and update this outlook as we learn more. Vaccination remains the best way to protect yourself and your loved ones against serious outcomes of flu, COVID-19, and RSV. Vaccination is especially important for people who are at higher risk of developing serious complications.

Keep reading: 2023-2024 Respiratory Disease Season Outlook – October Update

October 27, 2023, 4:00 PM EDT

What CDC knows
The SARS-CoV-2 virus, which causes COVID-19, is constantly changing and new variants continue to emerge. A variant is a change in the virus. A new variant may infect people more easily, spread faster, or cause people to get sicker. Nevertheless, nearly all the SARS-CoV-2 variants currently circulating in the United States are closely related to the variant used for the updated 2023-2024 COVID-19 vaccines. This means that the updated vaccines should work well against currently circulating variants and continue to be the best way to protect yourself and others against severe disease.

What CDC is doing
CDC uses multiple systems to understand which SARS-CoV-2 viruses are circulating in communities, where they are circulating, and whether they are likely to contribute to surges in infection or serious illness. CDC then communicates these findings to the public.

Keep reading: Variants Happen

October 19, 2023, 1:30 PM EDT

What CDC knows
Vaccines are an important way to boost your immunity and prevent severe illness from flu, COVID-19, and RSV this fall and winter. These vaccines are only useful if you can access them.

What CDC is doing
There are ways to get free vaccines.

Keep reading: How to Get Your Flu, COVID-19, and RSV Vaccines This Year

October 13, 2023, 2:00 PM EDT

What CDC knows
COVID-19 vaccines save lives and help keep you out of the hospital. Vaccines are not always effective at preventing infection, but there is extensive data showing that these vaccines prevent severe illness and protect the public’s health.

What CDC is doing
CDC is continually assessing how effective COVID-19 vaccines are against this disease. Intensive safety monitoring has been conducted since the first COVID-19 vaccines came out in 2020 and is ongoing.

Keep reading: Things You Should Know about COVID-19 Vaccines

September 29, 2023, 6:00 PM EDT

What CDC knows
Immunizations against COVID-19, flu, and respiratory syncytial virus (RSV) are available and can help protect people against severe illness during the fall and winter season, when these diseases are more common.

What CDC is doing
CDC has provided immunization recommendations for providers and the public and is continuing to communicate about who should get immunizations, the benefits of immunization, and how to find recommended immunizations.

Keep reading: Immunization Overview for Fall and Winter 2023-2024

September 29, 2023, 1:30 PM EDT

What CDC knows
Pregnant and recently pregnant people are at increased risk of being hospitalized with COVID-19 and flu. Babies are also more likely to get very sick from COVID-19, flu, and respiratory syncytial virus (RSV).

What CDC is doing
CDC recommends COVID-19 and flu vaccination for pregnant people to help protect themselves and their babies from COVID-19 and flu. CDC also recommends RSV vaccination for pregnant people to protect their babies from RSV.

Keep reading: Respiratory Virus Vaccination for Pregnant People

September 22, 2023, 5:00 PM EDT

What CDC knows
Respiratory Syncytial Virus (RSV) can cause serious illness in infants, young children, and older adults. RSV season is right around the corner and immunization is an important way to protect against severe RSV.

What CDC is doing
Today, CDC recommended an RSV vaccine for people who are 32-36 weeks pregnant to help protect their babies from severe RSV. CDC has also recommended RSV immunization to protect babies and toddlers. For older adults, CDC recommends an RSV vaccine, using shared clinical decision-making.

Keep reading: Update on RSV and New Vaccine Recommendation

September 15, 2023, 3:00 PM EDT

What CDC knows
It is unclear how easily BA.2.86 spreads compared to other circulating variants. At this time, BA.2.86 does not appear to be rapidly increasing or driving increases in infections or hospitalizations in the United States.

What CDC is doing
CDC will continue monitoring BA.2.86 and other circulating variants of the virus that causes COVID-19. Moving forward, we will share updates on BA.2.86 when significant additional information becomes available.

Keep reading: Sept 15 Update on COVID-19 Variant

September 14, 2023, 11:30 AM EDT

What CDC knows
Analysis from CDC’s Center for Forecasting and Outbreak Analytics shows that with the addition of a third virus (COVID-19) that can cause severe illness, even an average respiratory season can place significant strain on our healthcare system.

What CDC is doing
CDC recommends staying up to date on the vaccines recommended for you as an important strategy to prevent severe disease and protect yourself and others around you. Higher levels of vaccination across the population will also help reduce the number of hospitalizations and risk of hospital strain.

Keep reading: Respiratory Disease Season Outlook

September 12, 2023, 9:00 PM EDT

What CDC knows
COVID-19 continues to be a major cause of serious respiratory illnesses in the United States, with more than 200,000 deaths (including more than 600 in children and adolescents 0-19 years old) reported since January 2022. Vaccination is the most effective tool to protect yourself from severe illness this fall and winter.

What CDC is doing
CDC recommended a COVID-19 vaccine updated for 2023-2024 for everyone aged 6 months and older to protect against serious illness.

Keep reading: Updated COVID-19 Vaccine Recommendations Now Available

September 8, 2023, 5:30 PM EDT

What CDC knows
The U.S. 2023-2024 flu vaccines have a similar vaccine virus composition as the 2023 Southern Hemisphere flu vaccines.

What CDC is doing
A new CDC study found that people who had received a flu vaccine were half as likely to be hospitalized with flu compared to people who had not been vaccinated.

Keep reading: Flu in the Southern Hemisphere

September 8, 2023, 11:30 AM EDT

What CDC knows
Early research data from multiple labs are reassuring and show that existing antibodies work against the new BA.2.86 variant.

What CDC is doing
Real-world data are needed to fully understand the impact given the complexities of the immune response to this variant. Studies are ongoing, and we expect to learn more in upcoming weeks.

Keep reading: Sept 8 Update on COVID-19 Variant

August 30, 2023, 3:30 PM EDT

What CDC knows
At this time, we don’t know how well this variant spreads, but we know that it spreads in the same way as other variants. Take preventative actions to protect yourself and others from infection.

What CDC is doing
CDC is tracking a new SARS-CoV-2 variant called BA.2.86 and working to better understand its potential impact on public health.

Keep reading: Update on COVID-19 Variant

August 23, 2023, 10:10 AM EDT

What CDC knows
A new variant of SARS-CoV-2 called BA.2.86 was detected in Denmark and Israel.  This variant is notable because of a large number of genetic differences from previous versions of SARS-CoV-2.

What CDC is doing
Based on what CDC knows now, we’ve prepared a scientific assessment of the risk profile posed by BA.2.86.

Keep reading: COVID-19 Variant