Viral Infections

A UK prospective study (conducted in 2020-2021) including 2100 people with asthma (that had had a vaccine booster in the past) reported that getting a COVID-19 infection increased the risk of asthma exacerbation by:

• 5 fold for any asthma flare-up (adjusted OR 5.11 (4.19 to 6.24) for booster within 12 months and 5.60 (2.98 to 10.53) for booster over 12 months ago)
• 6 to 9 folds for severe asthma flare-ups (requiring OCS, ED visit or hospitalisation), depending on the time since the booster was received , although the difference in risk between under and over 12 months was not statistically significant: adjusted OR 6.59 (4.70 to 9.22) for booster within 12 months and 9.20 (3.56 to 23.78) for booster over 12 months ago
• these results were adjusted/controlled for asthma treatment level (severity) and history of past flare-ups, amongst other potential confounders.

This study indicates that having a COVID infection continues to increase the risk of asthma flare-up in people with asthma, independently of asthma severity and asthma exacerbation history.

While the results suggest that longer time since vaccination increases the risk of severe asthma exacerbation, the difference was not statistically significant (confidence intervals overlap) and this requires further investigation.

A literature review (ref 1) published in 2025 summarising evidence on the burden of RSV in adults with asthma or COPD highlighted that:

• A population-based study in New Zealand reported that the adjusted risk of RSV hospitalisation increased by 6.7; 7.6 and 8.2 folds in people with asthma aged 18-49; 50-64 and 65-80 respectively, compared to people without asthma.(ref 1, 2)
• Two studies reported that 49-65% of patients 60 years and older with asthma hospitalised with RSV experienced asthma exacerbations.(ref 1)

Lung foundation Australia carried out a survey involving more than 3,300 adult participants in 2024 to better understand barriers to adult vaccination, and information and support needs.

Participants:

• Over 3,300 adults
• 41% had a lung disease (of which, 57% had asthma, 65% had an additional chronic condition and 26% had more than one lung disease)
• 79% women, 20% men, 1% gender diverse

Findings:

• 87% agreeing that adult vaccinations improve the health of the population
• 85% agreed that it’s important for adults to receive all vaccinations recommended for them
• 83% supported setting national adult vaccination coverage targets
• 86% supported increased government investment in vaccination support and information
• Top barriers to receiving vaccination: 1st out-of pocket cost; 2^nd don’t know which vaccines are free; 3^rd don’t know which vaccine to get or when
• 3 in 4 (75%) contracted either COVID-19, influenza, pneumococcal disease, whooping cough or respiratory syncytial virus in the last two years: for 1 in 5, this infection had a major impact on their lung health.
• 45% of 18-49yo did not know which vaccines are free
• 42% of 18-49yo did not know which vaccines to get and when

The report/LFA recommends and advocates for:

• Implementing adult vaccination targets
• Recognise Australians living with a lung disease as a priority population for vaccination
• Vaccination awareness campaigns and community education
• Support primary care to better meet vaccination needs
• Free vaccinations for all clinically recommended vaccines on the NIP

Read the report to find out more including for specific respiratory conditions/vaccines.

– RSV vaccination is new, and has not been considered yet with the Australian Asthma Handbook guidelines.
– ATAGI recommends a single dose of Arexvy RSV vaccine for: (ref 1)
* all adults aged 75 and over
* Aboriginal and Torres Strait Islander peoples aged 60-74
* adults aged 60-74 with a medical condition increasing their risk of severe disease due to RSV, including severe asthma (defined as requiring frequent medical consultations or the use of multiple medicines)
– Arexvy can be co-administered with other vaccines, although this may increase mild-to-moderate adverse events.
– The need for further doses in the future has not yet been established. Recommendations on the need for subsequent doses will be provided when evidence is available.
– Abrysvo, another RSV vaccine, has been registered with the TGA in March 2024 for use in pregnant women and in adults 60 and over, however it is not available in Australia yet (as of 14 May 2024) (ref 2)

To protect infants/young children:(ref 2)
– monoclonal antibodies against RSV are currently available in Australia to immunise young infants and children up to 2 years. These are only available through certain states/territories programs (WA, QLD and NSW are funding nirsevimab for infants, see reference 2 for specifics of the programs)
– a RSV vaccine to immunise pregnant women: Abrysvo was registered by the TGA in March 2024 for use in pregnant women, however it is not available yet (as of 14 May 2024)

In childhood:
According to the Australian Asthma Handbook: (ref 1)
– severe respiratory viral infections during infancy, including with respiratory syncytial virus (RSV) and rhinovirus, are a risk factor associated with childhood asthma
– early life lower respiratory tract infections with RSV or Rhinovirus are strongly associated with allergic asthma in childhood.
– it is estimated that the attributable risk of asthma due to RSV is 13-22% in children 5 years and under, 11-27% in children 5-11 and 32% in children 12 and over. (This means that 13-22% of asthma occuring in 0-5 yo is thought to be due to RSV infection, etc)

In adulthood:
– Some medical conditions are associated with an increased risk of complications from RSV disease, including COPD and severe asthma (defined as requiring frequent medical consultations or multiple medicines). (ref 2)
– Older adults (particularly aged over 65), people with heart and lung disease, or people with weakened immune system are at higher risk of complication and hospitalisation. They may develop pneumonia, worsening asthma or COPD and congestive heart failure. (ref 3)
– adults that get an RSV infection typically have mild cold-like symptoms, however they may also develop a lung infection or pneumonia. RSV can also sometimes lead to worsening asthma, COPD and congestive heart failure.(ref 3, 4)

– RSV is a virus transmitted by respiratory secretions, and commonly causes upper and lower respiratory tract infection. Repeated infections are common throughout life because natural infection does not confer long-lasting immunity.
– in adults, RSV usually causes upper respiratory tract infection symptoms (cough, sore throat, nasal congestion etc). Lower respiratory tract infection can also cause wheezing and breathing difficulty.
– in children, the first RSV infection usually occurs by 2 years of age.
– The highest burden of RSV disease is among very young children and elderly people.
– RSV is the leading cause of hospitalisation due to lower respiratory tract infection and bronchiolitis in infants aged under 6 months. Most hospitlisations occur in children that are otherwise healthy.
– Hospitalisation rates decline with age after early childhood, then increase again from 50 to 65 years of age.
– Aboriginal and Torres Strait Islander adults have an increased risk of severe disease and hospitalisation due to RSV.

– so far 32k notifications in Quarter 1 which far exceeds the 15K notified in Q1 2023
– 37,002 cases up to 9/04/2023

– About 128,000 RSV lab-confirmed cases were notified in 2023, with the highest numbers in NSW (46,533; rate 90 per 100,000), QLD (28,787; rate 85 per 100,000) and VIC (25,232; rate 25 per 100,000)
– notifications were the highest in quarter 2 2023: 15K cases in Q1; 57K in Q2; 43K in Q3; 13K in Q4
– highest number of notifications in children 0-4 (64K) then 5-9 year olds (7k) and people aged 85+

Flu season 2024:
– So far this year, there have been 30,457 notifications of laboratory confirmed influenza reported to the NNDSS in the year to 3 April: ACT 420; NSW 12,382; NT 271; QLD 8,305; SA 1,747; TAS 219; VIC 5,367; WA 1,746 (ref 1)
– compared to previous years, there has been a high number of lab-confirmed influenza cases reported in January, February and March 2024. (ref 1)
– Latest statistics from quarter 1 of 2024 show an increase by 29% in laboratory-confirmed cases of Influenza in Australia, compared to the same period in 2023. (ref 2)
– as of 18 March 2024, national influenza statistics suggest we could be facing our second consecutive early influenza season. The Immunisation Coalition urges all Australians that now is the best time to get your influenza vaccination in preparation for the upcoming influenza season.(ref 2)

Note: cumulative notfications can be accessed live at: https://nindss.health.gov.au/pbi-dashboard/. As of 9/04/2024, there were 33,313 cases of influenza notified. the dashboard also provides age-specific numbers. Of these 33K cases, 9,165 (27.5%) were in children aged under 15. So far, children 0-9 are the age groups with the highest number of notifications. (ref 3)

According to the Australian Asthma Handbook:
– Viral respiratory infections are the most common trigger for asthma flare-ups, including serious acute asthma requiring hospital admission
– Reliever medicines may not be as effective during colds
– Children with both allergy and asthma have more severe and long-lasting virus-induced symptoms (both cold symptoms and asthma symptoms) than Children with asthma but no allergy
– people with asthma and allergies are at higher risk of asthma hospitalisation than those without allergies
– In practice, it is not feasible to avoid colds or influenza. Colds and influenza are spread by multiple routes, including airborne transmission of small and large droplets generated by talking and coughing, and transfer by fingers from contaminated items to the nose or eyes.
– People with asthma should avoid crowded and enclosed spaces, particularly where there are people with colds.

Management of viral infections/cold and asthma:
– ensure instructions about managing asthma at the onset of a cold are described in an Asthma Action Plan
– some patients with asthma may be sensitive to aspirin and/or NSAIDs (e.g. ibuprofen): do not take aspirin or NSAIDS if you have experienced runny nose or wheezing within 1-2 hours of taking these medications in the past. Taking these could worsen your asthma symptoms.

In children, asthma hospitalisations tend to peak in February, most likely due to respiratory infections associated with return to school and childcare after the summer break.

In adults, the peak period of severe viral-associated flare-ups occurs in the winter.

According to the Australian Asthma Handbook:
– Viral infections are the most common trigger for asthma flare-ups, including serious acute asthma requiring hospital admission
– influenza is spread by multiple routes, including airborne transmission of small and large droplets generated by talking and coughing, and transfer by fingers from contaminated items to the nose or eyes.

Immunisation recommendations from the Australian Asthma Handbook
– influenza vaccination reduces the risk of influenza, however the level of protection it confers against asthma flare-ups is uncertain (ref 1)
– patients with severe asthma (defined as having frequent hospitalisations and requiring multiple asthma medicines) should keep their influenza vaccination up to date. Other adults with asthma should follow national immunisation guidelines and be informed of the potential benefits of flu vaccination. (ref 2)
– the flu vaccine is free of charge for people with severe asthma (defined as requiring frequent medical consultations OR the use of multiple medications) (ref 2)

Immunisation recommendations from the National Immunisation Handbook: (updated 15 March 2024).
– Yearly influenza vaccination is recommended for all people aged 6 months and over (children and adults)
– influenza vaccination is funded on the NIP (free of charge) for:
* children 6 months to under 5 years
* people aged 65 years and over
* First nations people (aged 6 months and over)
* pregnant women
* people with certain medical conditions aged 6 months and over: this includes people with severe asthma (defined as requiring frequent medical consultations or the use of multiple medicines)

Flu season 2023:
– The 2023 influenza season was characterised by an early peak and longer duration, but overall lower clinical severity and societal impact, than many pre-COVID-19 pandemic influenza seasons
– vaccination coverage was low overall in 2023, especially in children, and severe
presentations to sentinel hospitals in children were reported throughout the season
– there were 252,296 notifications of laboratory-confirmed influenza cases, 376 influenza associated deaths (median age 76 years); and 3,696 sentinel hospital admissions
– Children aged 05–09 years had the highest influenza notification rates followed by children aged 0–04 years. The notification rate was lowest among adults aged 70–74 years.
– Influenza vaccine coverage rates were lower in 2023 (at 32% overall) than in 2022 (39%), and lower overall in First Nations peoples (24%).
– vaccine coverage in children was low (21% in under 5 yo)
– 72% of hospitalisations reported by sentinel hospitals were in children under 16 (although sentinel admissions may overestimate hospital admissions nationwide for children under 16)

Report/Information paper by the Lung Foundation that discusses the results from their national survey (2196 responses) about the experiences of Australians throughout the COVID-19 pandemic and the impact of ongoing COVID-19 symptoms, particularly for the lung disease community. This report outlines the following:
– Experience of Australians through the pandemic
– Experience of Australians living with a lung disease or other chronic condition
– Experience of carers
– Healthcare access
– Mental health
– Immunisation
– The view of Australians on disease prevention, the future and government trust
– Recommendations

Extract from AIHW Chronic respiratory conditions report:

COVID‑19 impact on chronic respiratory conditions

The COVID‑19 pandemic had substantial impacts on hospital activity generally. The range of social, economic, business and travel restrictions, including restrictions on, or suspension of, some hospital services, and associated measures in other healthcare services to support physical distancing in Australia, resulted in an overall decrease in hospital activity between 2019–20 and 2020–21. As a result, the hospitalisation rates for asthma and COPD in these years were the lowest recorded in the last 10 years (AIHW 2022a).

For more information on how the pandemic has affected the population’s health in the context of longer-term trends, see ‘Changes in the health of Australians during the COVID‑19 period’ in Australia’s health 2022: data insights.

Emergency department presentations for asthma and COPD were also affected by the pandemic, decreasing from March (when the national lockdown started) to May 2020 (from 26 to 11 and 39 to 28 presentations per 100,000 population, respectively).

In June 2020, emergency department presentations increased again as restrictions began to ease across the country (to 19 presentations per 100,000 population for asthma and to 33 presentations per 100,000 population for COPD) (Figure 9).

During the COVID‑19 pandemic (as at 31 October 2022), chronic respiratory conditions were certified as a pre-existing condition in 18% of the deaths with a chronic condition mentioned, the third highest of all chronic conditions (ABS 2022)

Death rates due to all respiratory diseases combined also showed a substantial fall in 2020, with rates particularly low for females and during the winter months compared with previous years, though rates have increased since (Figure 10).

While the long-term impact of COVID‑19 on the respiratory system is still being assessed, evidence shows that COVID‑19 does not directly impact the risk of increasing asthma severity and vice versa (Lee et al. 2020; Lieberman-Cribbin et al. 2020; Mather et al. 2021). However, there is increasing evidence showing that COPD patients with COVID‑19 have greater risk of mortality, severity of infection and higher likelihood of requiring Intensive Care Unit (ICU) support than those without COPD (Cazzola et al. 2021; Clark et al. 2021; Wells 2021).

For more information, see ‘The impact of a new disease: COVID‑19 from 2020, 2021 and into 2022’ in Australia’s health 2022: data insights.

Key Guidelines:
– Australian Asthma Handbook, v2.2, COVID webpage (ref 1)
– GINA COVID guidance (ref 2)
– Severe asthma toolkit: Clinical recommendations for COVID-19 in Severe Asthma + several infographics for people with severe asthma (ref 3)

Infographics can be accessed here: https://toolkit.severeasthma.org.au/resources/infographics/

key messages:
* People with asthma face no greater risk of becoming infected with COVID.(2)
* People with well-controlled asthma are not at greater risk of severe illness, going to hospital or dying from COVID, however people with severe or uncontrolled asthma (e.g. have needed oral corticosteroids or were hospitalised in the last 12 months) are. (1-6)

HOSPITALISATION:
– Adult patients with a history of asthma attack requiring oral corticosteroids (OCS) or hospitalisation are at increased risk of COVID hospitalisation, compared to patients without asthma. (1) Specifically:
– patients with a history of one or more asthma attacks in the last 2 years, defined as receiving one or more course of oral corticosteroids, had an adjusted HR between 1.30 (one course) and 1.54 (3 or more courses). (1)
– patients hospitalised for asthma in the last 2 years were about 3 times more likelly to be hospitalised for COVID than patients without asthma (adjusted HR 3.01), although this was calculated based on a small group of patients (201 patients with asthma hospitalisation). (1)

– in a Scottish study, children aged 5-17 years with uncontrolled asthma (defined as hospital admission or oral corticosteroids prescription in the last 2 years) had at increased risk of hospital admission for COVID, with a risk increased by at least 6-fold for those with a history of asthma hospitalisation, and at leat 3-fold for those with a history of at least 2 courses of OCS in the last 2 years. The rate of hospitalisation was higher in children with poorly controlled asthma compared to those with well-controled asthma or no asthma.(2)

– in a large national cohort study in England in adults and children aged 12-17 years old:(3)
– adults with asthma prescribed medium and high ICS had an elevated risk of COVID hospitalisation (fully adjusted HRs 1.53 and 1.52 respectively) compared to people without asthma.
– adults with asthma had a significantly higher risk of COVID hospitalisation, with those prescribed 2 or more courses of OCS in the year prior to the pandemic having an adjusted HR of COVID-19 hospitalisation of 1.94 compared to adults without asthma. => Nearly twice as likelly to be hospitalised for COVID
– children (12-17 yo) with asthma had a greater risk of hospitalisation compared to children without asthma, and was the greatest for children prescribed 1 (HR 2.58) or 2 or more (HR 3.80) courses of OCS in the year prior to the pandemic. => children prescribed OCS were more than twice as likelly to be hospitalised than children without asthma (nearly four times for children prescribed 2 or more courses).
Concl: People with asthma who recently required higher ICS dosage-based therapies (ie, have more severe disease) or who experience one or more exacerbations per year (ie, have poorly-controlled asthma) as measured by OCS prescriptions, are potentially at increased risk of hospitalisation (particularly those that required 2 or more courses of OCS).(3)

MORTALITY:
– Adults with asthma have a similar risk of dying from COVID compared with people without asthma.(1)
– when hospitalised for COVID, People with severe asthma (16yo +) are more likely to die than people without asthma (adjusted Hazard Ratio 1.96; 95% CI 1.25-3.08).(2)
– In a Scottish study, the risk of death from COVID was increased in asthmatic patients with a 2-year history of 3 course or more of oral corticosteroids (adjusted HR 1.39) or asthma hospitalisation (adjusted HR 1.84) compared to patients without asthma. (3, supplementary material table S7)

– In a large national cohort study in England:(4)
– increased risk of COVID death in Adults with asthma prescribed medium and high ICS (adjusted HRs 1.18 and 1.36 respectively) compared to adults without asthma, but no significant increase in people with asthma prescribed low ICS.
– increased risk of COVID death in adults with asthma prescribed 0 (adjusted HR 1.10), 1 (adjusted HR 1.20), 2 or more (adjusted HR 1.60) courses of OCS in the year prior to the pandemic compared to adults without asthma.
Concl: People with asthma who recently required higher ICS dosage-based therapies (ie, have more severe disease) or who experience one or more exacerbations per year (ie, have poorly-controlled asthma) as measured by OCS prescriptions, are potentially at increased risk of death from COVID (particularly those that required 2 or more courses of OCS).(4)

CRITICAL CARE:
– When hospitalised for COVID, people with asthma are more likely to receive critical care than people without underlying respiratory condition. (1)(2)
– There is an indication, although not statistically significant, that PWA have an increased risk of hopitalisation and critical care (ICU admission and ventilator use) compared to people without asthma.(3)
– Adults with asthma that have a history of asthma attack in the preceding 2 years (defined as two or more courses of oral corticosteroids (OCS), or at least one previous asthma hospitalisation) have an increased risk of ICU admission or death, compared with COVID patients without asthma (adjusted HR between 1.44 and 1.27 for history of OCS; adjusted HR = 2.24 for history of asthma hospitalisation, compared to patients without asthma). Suplementary material (table S7): the risk of ICU admission was higher in patients with a history of one or more course of OCS (adjusted HR 1.23 to 1.89) and in patients with a history of asthma hospitalisation (adjusted HR 3.48) compared to patients without asthma. (4)

in hospitalised (severe COVID) patients: (1)
A large prospective cohort study reported that amongst patients hospitalised with COVID, asthmatic patients aged 50 and over that used ICS within 2 weeks before hospitalisation were 14% less likely to die than patients without chronic respiratory conditions.

– It was estimated that about 8% of adult COVID-positive patients have asthma1
– Adults with asthma are 17% less likely to contract COVID than non-asthmatic patients (risk ratio=0.83, p=0.01)1
– Global Initiative for Asthma (International guidelines) states that patients with asthma are not at increased risk of acquiring COVID-19, or of severe COVID-192

GINA International guidelines recommendations1:
– Advise patients to continue taking their prescribed asthma medicines, including ICS and biological therapies
– Avoid the use of nebulizers where possible, due to the risk of viral transmission
– COVID vaccination is recommended for people with asthma
– Consider giving biological therapies on a different day from COVID vaccination

URGENT CARE In mild COVID patients, Randomised Controlled Trials Budesonide vs Usual Care:
– significanttly less patients required urgent care in group using budesonide compared to usual care (relative risk reduction 91% for budesonide), in the STOIC trial (small number of participants, aged 18+). (1)
– in PRINCIPLE, a much larger trial with patients at risk of deterioration (older/with co-morbidities), there was a (non-significant) indication of reduced hopitalisation or death in the budesonide group, although superiority was not demonstrated. (2)

RECOVERY in mild COVID patients,Randomised Controlled Trials Budesonide vs Usual Care :
– Time to recovery was 1 day shorter in the STOIC trial and 2.94 days shorter in the PRINCIPLE trial in the budesonide group compared to usual care. (1, 2)
– both trials indicated a quicker resolution/reduction of symptoms in the budesonide group. (1,2)
– both trials were open-label (participants know if they are taking ICS or not) implying a potentially significant placebo effect, particularly for self-reported time to recovery.